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Intensifying pastoralism may not reduce greenhouse gas emissions: Wildlife-dominated landscape scenarios as a baseline in life-cycle analysis
Abstract
Livestock-related Life Cycle Analyses (LCA) have consistently identified extensive livestock systems as the most emission-intense sources of greenhouse gases, which has triggered calls for a livestock intensification policy, including the promotion of monogastrics in zero-grazing systems. This is in contrast with advocates for pastoralist systems that depict them as biodiversity-friendly and helpful against land degradation. Here we reconcile both perspectives by showing that grazed ecosystems have a certain level of natural baseline emissions, which will be caused either by free ranging livestock or by wild animals able to digest cellulose. Such emissions cannot be considered anthropogenic and policies aimed at intensifying pastoralist production will therefore not have a positive effect on climate change. Future LCA should include baseline emissions from ecosystems.
... However, with intrinsic spacious-temporal variability and a long human activity, it is difficult to define herbivory baselines of potential Open Ecosystems (Hempson et al. 2017). The dynamics of herbivory and fire have been discussed theoretically, but there are limitations to quantifying them (Hempson et al. 2017;Manzano and White 2019;Archibald et al. 2019;Adie and Lawes 2023). ...
... In Open Ecosystems, some natural and anthropic processes linked to both wild and domestic herbivores are, to a large extent, mutually equivalent. This includes, among others, the configuration of the landscape and the vegetation structure, and GHG fluxes (Smith et al. 2010;Hristov 2012;Kim et al. 2013;Smith et al. 2016;Manzano and White 2019). Herbivore densities have hence great implications for burning environmental questions such as biodiversity maintenance or climate change. ...
... At the same time, some authors have demanded that the consideration of baselines can be important in environmental assessment (Pardo et al. 2023) and policy-making (Moncrieff et al. 2016), for example, when supporting or limiting pastoralism (Manzano et al. 2023a). In sum, new methodological approaches demand delving into a specific framework for Open Ecosystems that explicitly includes and quantifies baseline values (Manzano and White 2019). ...
Context
There are no estimations of herbivory baselines in Spain. Due to the bioclimatic conditions, ungulates have maintained Open Ecosystems until the Holocene. Pastoral tradition later fulfilled the niche of wild grazers, but this role is not considered in environmental assessments of grazing livestock.
Objectives
We attempted to better understand the scale of herbivory in Spain. We aimed to estimate the weight of current wild herbivory and evaluate the role of domestic herbivory in these baselines. We applied them to improve the allocation of environmental impacts and emissions from grazing livestock.
Methods
We inferred an equation relating Net Primary Productivity (NPP) with ungulate biomass and enteric CH 4 with data from 11 Spanish Protected Areas. We estimated theoretical baselines in Spain using other literature sources. We applied the equations to the Spanish open ecosystems that are currently grazable. We also estimated the proportion of grazing livestock that would be part of such baseline.
Results
We found relationships between NPP and ungulate biomass and enteric CH 4 emissions. However, current abundances are several times below the estimated baselines and the carrying capacity. There are major constraints for herbivore populations to reach their baseline state, particularly the absence of migration and the extinction of grazers among wild herbivores. Structural maintenance of Open Ecosystems should therefore be complemented by domestic grazers that cannot be replaced by the extant wild, mostly browser, ungulates.
Conclusions
We concluded that Spain is widely susceptible to being populated by herbivores that generate Open Ecosystems as baseline landscapes. Current grazing livestock accounts for a significant part of them, so baselines must be included in their environmental assessments. For the case of Spain, we propose a minimum baseline equivalent to 36% of current grazing livestock biomass and 23% of their enteric CH 4 emissions.
... Grazing livestock and wild herbivores occupy similar ecological niches, raising the question whether abandonment of pastoralism would necessarily lead to a significant reduction of emissions 8 . Large herbivores attain biomass densities in wild or rewilded landscapes that are particularly high in Sub-Saharan Africa and, to a lesser extent, South and South-East Asia 9 . ...
... There, unlike in other areas, guilds of large herbivores have been preserved up to the present. Recolonization of abandoned rangelands by large herbivores is thus likely to reach very high densities 10 , and such wild fauna can potentially attain high levels of GHG emissions 8 . In order to check for the relevance of this process of herbivore substitution, the hypothesis needs to be tested with current field data comparing analog ecosystems grazed by livestock and wildlife. ...
... Our research points to a significant overlap of managed and natural rangelands, especially when conservation or climatic policies are proposed that suggest massive conversion of a given land from one category into the other 6 . We can help nuancing current calls to shift into plant-based diets to increase the sustainability of the food system 24 , because the resulting abandoned land will clearly not be a zero-emission scenario 8 . Instead, livestock systems that mimic natural migratory herbivore systems as much as possible, such as mobile pastoralism, should be promoted to mitigate climate change at the expense of industrialized high-input production systems 10,25 . ...
Pastoralism in Old World savannas is known to emit a significant share of global livestock-sourced greenhouse gases (GHG). Here, we compare calculated emissions from animals in a wildlife-dominated savanna (14.3 Mg km ⁻² ), to those in an adjacent land with similar ecological characteristics but under pastoralism (12.8 Mg km ⁻² ). The similar estimates for both, wildlife and pastoralism (76.2 vs 76.5 Mg CO 2 -eq km ⁻² ), point out an intrinsic association of emissions with herbivore ecological niches. Considering natural baseline or natural background emissions in grazing systems has important implications in the analysis of global food systems.
... At the same time, some authors have demanded that the consideration of baselines can be important in environmental assessment (Pardo et al. 2023) and policymaking (Moncrieff et al. 2016), for example, when supporting or limiting pastoralism (Manzano et al. 2023a). In sum, new methodological approaches demand delving into a speci c framework for Open Ecosystems that explicitly includes and quanti es baseline values (Manzano and White 2019). ...
... An herbivory baseline implies that enteric herbivore emissions have been part of the natural uxes in the past and have a degree of inevitability in the future, because such emissions are consubstantial to the grazing ecological niche that dominates Open Ecosystems (Manzano and White 2019). Considering a signi cant fraction of current herbivory as a natural process, as done in the present study, or in Pardo et al. (2023) contrasts from the conventional approach of most studies. ...
... can be catalogued as anthropogenic (Manzano et al. 2023b). At this point, herbivory baselines, i.e. potential ecosystem effects from wild herbivory, must be calculated to evaluate strategies that aim to reduce either global warming, biodiversity loss or other land-use-associated impacts (Manzano and White 2019;Scoones 2022). Challenges for estimating herbivore baselines Our results are constrained by a signi cant degree of uncertainty, and there is still room to re ne methodologies -e.g. for measuring wild ungulate abundance on the eld. ...
Context
There are no estimations of herbivory baselines in Spain. Due to the bioclimatic conditions, ungulates have maintained Open Ecosystems until the Holocene. Pastoral tradition later fulfilled the niche of wild grazers, but this role is not considered in environmental assessments of grazing livestock.
Objectives
We attempted to better understand the scale of herbivory in Spain. We aimed to estimate the weight of current wild herbivory and evaluate the role of domestic herbivory in these baselines. We apply them to improve the allocation of environmental impacts and emissions from grazing livestock.
Methods
We inferred equations relating Net Primary Productivity (NPP) with ungulate biomass and enteric CH4 with data from 11 Spanish Protected Areas. We applied the equations to the current grazable areas in Spain and we analysed the ecological conditions to get the herbivory baseline. We also estimated the proportion of grazing livestock that would be part of such baseline.
Results
We found relationships between NPP and ungulate biomass and enteric CH4 emissions. However, current abundances are several times below the estimated baselines and the carrying capacity. There are major constraints for herbivore populations to reach their baseline state, particularly the absence of migration and the extinction of grazers among wild herbivores. Structural maintenance of Open Ecosystems must therefore be led by domestic grazers that cannot be replaced by the extant wild, mostly browser, ungulates.
Conclusions
We concluded that Spain is widely susceptible to being populated by herbivores that generate Open Ecosystems as baseline landscapes. Current grazing livestock accounts for a significant part of them, so baselines must be included in their environmental assessments. For the case of Spain, we propose a minimum baseline of 36% of the herbivore biomass and 30% of the enteric CH4.
... Beef cattle production has increased in the last three decades almost 40% worldwide, with the Americas being one of the regions that led this development [1]. However, beef produced from native grassland ecosystems provides multiple benefits such as biodiversity conservation, low energy and inputs consumption, carbon sequestration in soils, improved animal welfare, and rural development [2,3]. ...
... After the CoP21 meeting in Paris, there was a multinational agreement to act against climate change and that includes interventions in the livestock sector, by reducing methane emissions per unit of product (carbon footprint), in association with the promotion of sustainable grazing practices, so that the associated benefits of pastoralism are not sacrificed [3]. In this sense, using herbage mass efficiently by managing allowance per animal, is a key mitigation option in beef cow-calf grazing systems that can increase beef productivity and reduce carbon footprint [1]. ...
... Means within the same row followed by different letters are significantly different at p < 0.05. Organic matter digestibility, 2 Organic matter intake,3 Dry matter intake,4 Live weight , adjusted for uterine weight. ...
The aim of this study was to measure methane emissions (CH4) and herbage intake, and, on the basis of these results, obtain the methane yield (MY, methane yield as g CH4/kg dry matter intake (DMI) and Ym, methane yield as a percentage of Gross Energy intake), from beef cows grazing on native grasslands. We used forty pregnant heifers, with two treatments of herbage allowance (HA) adjusted seasonally (8 and 5 kg dry matter (DM)/kg cattle live weight (LW), on average), during autumn, winter and spring. Methane emissions (207 g CH4/d), organic matter intake (OMI, 7.7 kg organic matter (OM)/d), MY (23.6 g CH4/kg DMI) and Ym (7.4%), were similar between treatments. On the other hand, all variables had a marked increase in spring (10.8 kg OM/d and 312 g CH4/d), except for Ym. The methane emission factor from Intergovernmental Panel on Climate Change (IPCC) Tier 2 estimated with these results was 78 kg CH4/head/year. The results show that methane emissions and intake were influenced by the season, but not by the HA analyzed in this study. This information for cow–calf systems in native grasslands in Uruguay can be used in National greenhouse gases (GHG) inventories, representing a relevant contribution to global GHG inventories.
... This claim, however, needs to be scrutinized, as pastoralism not only provides wealth and nourishment to societies, but also provides other valuable ecosystem services, as stated above, and has the potential to obtain a neutral carbon balance (Assouma et al., 2019). Moreover, the opening of pastoral lands to rewilding needs careful consideration (Manzano and White, 2019), as it would ultimately lead to an increase in other methanogenic animals that do not significantly contribute to human nutrition and livelihoods (i.e., wild ruminants and termites). Although current domesticated ruminants produce large amounts of CH 4 , this may be comparable to historical wildlife (Hristov, 2012;Zimov and Zimov, 2014), with wild herbivores being less efficient in feed conversion (Manzano and White, 2019). ...
... Moreover, the opening of pastoral lands to rewilding needs careful consideration (Manzano and White, 2019), as it would ultimately lead to an increase in other methanogenic animals that do not significantly contribute to human nutrition and livelihoods (i.e., wild ruminants and termites). Although current domesticated ruminants produce large amounts of CH 4 , this may be comparable to historical wildlife (Hristov, 2012;Zimov and Zimov, 2014), with wild herbivores being less efficient in feed conversion (Manzano and White, 2019). ...
... Considerable progress can be achieved for monogastrics, by focusing on their potential for recycling food waste and leftovers Van Zanten et al., 2018;Uwizeye et al., 2019), as well as for ruminants, by adjustment of the grazing management and taxonomical and biochemical dietary diversity of ruminants at individual and herd level (Gregorini et al., 2017), improved channeling of waste streams, and better integration in the circular bioeconomy (Fairlie, 2011;Teague et al., 2016;Stanley et al., 2018). Rather than losing grasslands to annual agriculture and biofuel production, this includes working with the carbon storage potential of grasslands and rangelands, the added value of trees, the adoption of improved pasture species, better veterinary care, etc., which are also forms of intensification, in their own right (Manzano and White, 2019). This offers an entirely different mindset than the linear approach of Cartesian, mechanical thinking. ...
Humanity’s main societal and epistemic transitions also mirror changes in its approach to the food system. This particularly holds true for human–animal interactions and the consumption of animal source foods (red meat especially, and to a lesser degree dairy, eggs, poultry, and fish). Hunter-gathering has been by far the longest prevailing form of human sustenance, followed by a diffuse transition to crop agriculture and animal husbandry. This transition eventually stabilized as a state-controlled model based on the domestication of plants, animals, and humans. A shift to a post-domestic paradigm was initiated during the 19th century in the urbanizing populations of the Anglosphere, which was characterized by the rise of agri-food corporations, an increased meat supply, and a disconnect of most of its population from the food chain. While this has improved undernutrition, various global threats have been emerging in parallel. The latter include, among others, a public health crisis, climate change, pandemics, and societal class anxieties. This state of affairs is an unstable one, setting the conditions of possibility for a new episteme that may evolve beyond mere adjustments within the business-as-usual model. At least two disruptive scenarios have been described in current food discourses, both by scientists and mass media. Brought to its extreme, the first scenario relates to the radical abolishment of livestock, rewilding, a ‘plants-only’ diet, and vegan ideology. A second option consists of a holistic approach to animal husbandry, involving more harmonic and richer types of human–animal–land interactions. We argue that – instead of reactive pleas for less or none – future thoughtscapes should emphasize ‘more of the better.’
... However, since reduction rates in CH 4 intensity have been much larger than CO 2 increases, such trade-off seems to have had limited warming implications for the future in this particular case. This should, nevertheless, be taken cautiously: the reduction in CH 4 emissions by livestock no longer grazing on marginal areas may have been replaced by methane-emitting wild herbivores that would be occupying their former grazing niches in the ecosystem (Manzano and White, 2019). It is known that European wild herbivores are expanding into abandoned marginal grazing areas (Milner et al., 2006), so the net amount of CH 4 arising from the whole wild and domestic grazing system may have stayed around the same values. ...
... Moreover, these countries have abundant natural grazing ecosystems in their territory that can host many wild methane-producing herbivores. Total abandonment of grazing in natural rangelands is likely to be a very ineffective climate change policy (Manzano and White, 2019). ...
Recent calls advocate that a huge reduction in the consumption of animal products (including dairy) is essential to mitigate climate change and stabilise global warming below the 1.5 and 2°C targets. The Paris Agreement states that to stabilise temperatures we must reach a balance between anthropogenic emissions by sources and removals by sinks of greenhouse gases (GHG) in the second half of this century. Consequently, many countries have adopted overall GHG reduction targets (e.g. EU, at least 40% by 2030 compared to 1990). However, using conventional metric-equivalent emissions (CO 2 -e GWP 100 ) as the basis to account for emissions does not result in capturing the effect on atmospheric warming of changing emission rates from short-lived GHG (e.g. methane: CH 4 ), which are the main source of GHG emissions by small ruminants. This shortcoming could be solved by using warming-equivalent emissions (CO 2 -we, GWP*), which can accurately link annual GHG emission rates to its warming effect in the atmosphere. In our study, using this GWP* methodology and different modelling approaches, we first examined the historical (1990–2018) contribution of European dairy small ruminant systems to additional atmosphere warming levels and then studied different emission target scenarios for 2100. These scenarios allow us to envision the necessary reduction of GHG emissions from Europe's dairy small ruminants to achieve a stable impact on global temperatures, i.e. to be climatically neutral. Our analysis showed that, using this type of approach, the whole European sheep and goat dairy sector seems not to have contributed to additional warming in the period 1990–2018. Considering each subsector separately, increases in dairy goat production has led to some level of additional warming into the atmosphere, but these have been compensated by larger emission reductions in the dairy sheep sector. The estimations of warming for future scenarios suggest that to achieve climate neutrality, understood as not adding additional warming to the atmosphere, modest GHG reductions of sheep and goat GHG would be required (e.g. via feed additives). This reduction would be even lower if potential soil organic carbon (SOC) from associated pastures is considered.
... Pastoralists in highly variable environments are professionals in adapting to change and dealing with uncertainty while not relying on energy-intensive processes that have caused climate change in the first place. Key factors supporting pastoralists' resilience include strategic mobility, diversity of assets, adaptive resource management strategies, and strong customary institutions (Krätli, 2019), Manzano and White, 2019;Houzer and Scoones, 2021). ...
Most arid and semi-arid ecosystems in Africa are mainly dedicated to various types of extensive livestock production. These systems play an essential role in the valorization of natural spaces and resources. In addition to feeding humans and animals, pastoral livestock production provides a subsistence income to populations that would otherwise not be able to survive in these regions. This pastoralism has been threatened for several years. In almost all agropastoral areas of the continent, agricultural fronts are advancing and encroaching on pastoral areas. The monetization of access to water for watering and the taxation of access for transhumant livestock have multiple negative consequences: decapitalization of livestock, increased conflicts between users of rural areas, and dissolution of social ties between communities. Friction is amplified by the prevailing insecurity, banditry and armed conflicts, as in the Sahel, Nigeria, the Horn of Africa and the Great Lakes. The security crisis is taking a heavy toll on pastoralists. But for many analysts, solutions exist. The question is how to disentangle and redress the adverse dynamics, translating the recognition of pastoralists' rights and interests into texts and facts, ensuring their integration into local and national institutional and economic structures in order to extinguish their feeling of social exclusion and marginalization.
... In the case of pastoral systems (GS and PS), actions contributing to the increase in availability and quality of natural and cultivated grasslands are recommended, such as (i) adopting controlled grazing techniques [44], allowing the optimization of pasture production, and controlling spatial and temporal mobility of livestock with new technologies (e.g., tracking collars); (ii) improving the recycling and cycling of nutrients in crops; and (iii) introducing quality autochthonous herbaceous species (e.g., legumes) that contribute to balancing the forage supply. These actions contribute to pastoral systems reaching maximum food autonomy, reducing dependence on external food that has higher environmental costs due to their production and transportation system. ...
Simple Summary
The carbon footprint (CF) is, at present, the most widely used indicator to quantify the impact of livestock farming on global warming, fulfilling also the purpose of identifying production practices that develop more efficient uses of available resources, as well as ways to minimize their environmental impact. The aim of this study was to characterize the CF in the four different production systems of autochthonous dairy goat breeds currently occurring in Andalusia (S Spain), from confined to pastoral systems, also considering the carbon sink ability by vegetation associated with land-based livestock systems. Despite the difficulties of calculation, the relevance of using a species-specific standardization equation and of taking into account land carbon sink ability was demonstrated. The four production systems analyzed obtained similar CF values, all showing room for improvement. This must be translated into the adoption of specific actions for each production system and territory, particularly regarding the improvement of grazing activity, optimal use of farm resources, and appropriate management of manure or the use of local food. Professional advice, training, and the use of specific management tools are essential for the implementation of these strategies to move towards low-carbon goat production.
Abstract
The small ruminant livestock sector faces the challenge of reducing greenhouse gas (GHG) emissions. Carbon footprint (CF) studies on dairy goats, the most widely used indicator to quantify the impact of livestock farming on global warming, are still few. The aim of this study was to calculate the CF of the different production systems of autochthonous dairy goat breeds presently occurring in Andalusia (S Spain) and identify systems and practices that can minimize their environmental impact in these terms. Twenty-one farms were monitored during a year, obtaining valuable information that allowed the CF calculation on a “cradle-to-gate” approach, taking into account both GHG emissions at the farm level and carbon sink by vegetation associated with land-based systems. Results showed similar CF values for the analyzed systems (1.42, 1.04, 1.15, and 1.17 kg CO2-eq kg⁻¹ fat–protein corrected milk for indoor systems without associated crops, indoor systems with associated crops, grazing systems with high feed supply, and pastoral systems, respectively). To minimize their environmental impact, specific actions must be developed for each system, particularly regarding genetic improvement, reproductive and feeding management, including pasture management, and the integration of livestock activity into the bio-circular economy with the help of professional advice.
... Applied Vegetation Science LINDBORG et al. additionally reduce other greenhouse gas emissions generated from grazing livestock (Manzan & White, 2019). ...
Question
Semi‐natural grasslands (SNG) are important for maintaining biodiversity and ecological processes in farmland. Current pasture‐based livestock production mainly occurs on intensified grasslands (IG) that have been agronomically improved. Although it is documented that SNG and IG differ in terms of plant diversity, their ability to provide ecosystem services (ES) in farmland is less explored. Here, we review the role of SNG and IG in delivering ES, illustrate their trade‐offs and synergies, and examine how ES can be assessed by using plant traits and functional richness.
Results
We found that SNG generate a wider range of ES than IG. Trade‐offs exist between ES that appear more pronounced in IG between high biomass production and other ES. SNG are good in providing habitat for biodiversity, supporting pollination and cultural services. SNG also have a significantly wider range of plant functional traits and a higher functional richness, suggesting that the potential to supply ES in SNG is partly driven by higher number of species and their functional diversity.
Conclusion
Clearer trade‐offs were found in IG compared with SNG, supported both by the literature and the functional richness. This suggests that functional knowledge could be a good complement to understand the mechanisms behind ES generation and could help with tailoring grassland management to sustain biodiversity, ecological functions and ES. Although both IG and SNG are likely needed for the long‐term sustainability of food production, both could aim for a more balanced generation of ES, increasing biodiversity and functional redundancy at the landscape scale.
... When such lands are abandoned, as has happened after, e.g., the Chernobyl disaster, wild herbivores re-occupy the grazing niches, emitting CH 4 that is in turn considered a natural ecosystem flow. However, this exemplifies that the abandonment of grazing livestock, and the subsequent ecosystem changes that follow (e.g., loss of habitat for ground-nesting birds; Pearce-Higgins and Yalden, 2003), is not as effective as a global warming mitigation strategy as has been claimed (Manzano & White, 2019), as the balance from domestic herbivores disappearing from the landscape is not zero. This will be particularly significant in some developing countries with wellconserved herbivore guilds that achieve high biomass concentrations when undisturbed, such as East Africa or South Asia (Fløjgaard et al., 2022). ...
... Such natural GHG flows build up a natural baseline emission level and can have important implications on how grazing-based ruminant systems can be considered in the future. A pastoralism abandonment scenario would likely drive to either an increase in wild herbivore populations, more frequent wildfires, or both, constituting a scenario that in no case consists of zero GHG emissions (Manzano and White 2019) and that, according to estimates for global herbivore baselines, could translate into relevant emission levels (Manzano et al. 2023). At the global scale, a large portion of such systems implies traditional animal husbandry with negligible external inputs and varying degrees of livestock mobility as coping mechanisms for managing seasonal variations in vegetation growth-with obvious parallelisms to the Spanish transhumance system. ...
Purpose
Transhumance has rarely been analyzed through LCA approaches, and there is little evidence about its emissions level when conducted under different practices (by truck or on foot) or compared to sedentary livestock systems. Moreover, mobile pastoralism is strongly linked to natural resources by its seasonal grazing patterns, thereby occupying the niche of wild herbivores. Considering natural emission baselines in these ecosystems could have relevant effects when estimating their carbon footprint.
Materials and methods
Inventory data of 20 sheep farms was collected to estimate the carbon footprint (CF) of lamb meat produced. Farms were divided into three sub-groups representing typical management practices in the region: (1) sedentary (SED), (2) transhumance by truck (THT), and (3) transhumance on foot (THF). Livestock GHG emissions were modeled according to herd structure and IPCC guidelines. Off-farm emissions from external feeds and fuels were accounted based on existent LCA databases. A natural baseline of wild herbivores was established from the population of red deer reported in a hunting preserve, previously considered to be a reference for the natural carrying capacity in Mediterranean ecosystems. GHG emissions of wild herbivores were estimated through two methods based on (1) IPCC guidelines and (2) allometric regression equations.
Results and discussion
Carbon footprint ranged from 16.5 up to 26.9 kgCO2-eq/kg of lamb liveweight (LW). Significant differences were identified among sedentary and transhumant farms, the latter consistently showing lower CF values (SED: 25.1 kg CO2-eq/kg LW, THT: 18.3 kg CO2-eq/kg LW, THF: 18.2 kg CO2-eq/kg LW). Sedentary farms resulted in higher GHG emissions (+ 27%) and higher CO2 and N2O, contributions derived from the consumption of additional feeds. Both methods applied to compute emissions for wild herbivores led to similar results (25.3–26.8 Mg CO2-eq/km²), comparatively lower than estimation for transhumant sheep (47.7 Mg CO2-eq/km²). When considering natural baseline emissions, the CF of transhumant lamb meat is reduced by almost 30%, reaching values quite below those reported for intensive lamb production systems in Spain.
Conclusions
From our results, mobility of grazing livestock can be considered as a strategy promoting climate change mitigation. This is achieved mainly by reducing the need of external feeds, while maximizing the use of local forage resources that otherwise would be difficult to valorize. Further reductions in the CF result when considering natural baseline emissions. The application of this new GHG accounting perspective could have relevant implications when aiming at climate neutrality of grazing-based ruminant systems.
... These changes could lead to more frequent extreme weather. Therefore, we must reduce greenhouse gas emissions (Gillingham and Stock 2018;Manzano and White 2019), and effectively enhance the carbon absorption capacity of vegetation (Mohanty et al., 2018) to achieve the sustainable enhancement of the terrestrial environment as well as socioeconomic progress (Song et al. 2019;Yi et al., 2018). ...
Vegetation cover significantly improves the terrestrial environment by increasing carbon sequestration capacity. It is projected that a major threat to China's terrestrial environment will be happened by 2030 due to the increment in carbon emissions. Identifying reliable techniques to assess carbon absorption by green coverage is necessary to build a resilient environment. This research examines the performance of two weighted regression models to explain the capacity of vegetation carbon sequestration (VCS), spatial distribution, and degree of influence of vegetation coverage for reducing carbon emission. The results demonstrate changes in the VCS capacity from slow to fast, with an average yearly growth rate of 0.043% (2005–2010) to 1.963% (2010–2015) and more obvious growth in local cities. Variables such as the night-time light index, average relative humidity, and length of sunlight substantially impacted VCS capacity, although their effect varied yearly. Finally, the comparative results show that This study can play an influential role in finding specific locations facing issues with carbon emissions and can support local governments through the association of effective measures to mitigate it.
... (b) Even though economic benefit is not identified as a priority for farmers within the FF project (Table 3), generating additional profits for farms is a relevant aspect that needs to be addressed. Ensuring a fair economic return for the grazing activity in SMAs and CAs can be achieved either by improving the promotion of their products-with strong external conditioning from the market, strongly controlled by the industrialized agri-food sector [39]-or through a consolidated direct payment for the service [16]. The latter currently depends on the conditions of public administration policies, these being external to FF (Q3.5, Figure 7). ...
Nowadays, extensive livestock farming faces substantial threats in the Mediterranean region , provoking a setback dynamic in the sector. In 2016, the Fire Flocks (FF) project was conceived and implemented as a regional strategy to revert this situation and revalue the sector in Catalonia, in the NE of the Iberian Peninsula. FF promotes forest management through extensive livestock farming, and more specifically silvopastoralism, to reduce vegetation load and wildfire risk. The initiative also works on fire risk awareness with the aim of promoting extensive livestock products through FF label and valorization strategies. Five years after its initial implementation, the project managers detected several weaknesses and potential improvements directly affecting the economic and environmental performance of the participating farms. It was therefore considered necessary to conduct targeted qualitative interviews with the farmers participating in the project in order to gather their opinions on the project's functioning and further steps. To this end, 17 farmers were interviewed with the aid of a qualitative questionnaire. The farmers stated that although FF is not providing them with any direct financial benefits, it does present an opportunity to belong to a group of farmers working on wildfire prevention, thereby lending them a voice as a group, and reaching more social visibility. The qualitative analyses elucidate key elements to be promoted in FF, such as redesign of the operational structure, expansion to a regional scale and action lines to facilitate grazing activity.
... In 2015, livestock farming in Spain emitted 86.4 million tons of CO 2 equivalent, more than half of which is attributable to the agricultural production of animal feed and is therefore associated primarily with industrial animal production systems (Herrera, 2020). However, recent research highlights the caveats of the accounting methodologies used by the IPCC, which do not include a baseline scenario with wild herbivores also emitting greenhouse gasses (Manzano & White, 2019), or the carbon sink that grasslands and other natural pastures contribute (Freibauer et al., 2004). The impacts of climate change on Spanish grasslands have been extensively reported and include the loss of plant diversity, reduced soil moisture availability (the "Mediterraneanization" of the northern Iberian Peninsula and the aridification of the Southern area), rapid changes in species distribution that are driving extinctions and a resulting biotic homogenization, edaphic changes, changing wildfire regimes, increased frequency and impacts of extreme weather events like drought, or changes in seasonality that affect plant phenology and pollination, among others (Rubio & Roig, 2017). ...
... Species richness (number of species) 32.33 a ± 2.33 25.00 b ± 2.33 Soil microbial metabolic quotient (mg CO 2 m −2 h −1 /mg microbial C kg −1 soil) 0.93 a ± 0.28 1.20 b ± 0.26 Soil compaction (Mpa) 3.31 a ± 0.86 1.28 b ± 0.21 CN ratio 24.51 a ± 0.35 29.06 b ± 0.88 albedo are highly context-dependent (Bond et al. 2019), potentially counterproductive (Nuñez et al. 2021), and subject to large uncertainties as landscapes will be colonized by wild ruminants and other methane emitters (Manzano and White 2019). In terms of biodiversity, our results corroborate that livestock grazing exerts important and direct benefits for plant species richness, which also benefits the diversity of other aboveground and belowground organisms (e.g., insects, worms, microorganisms) (see also Wang et al. 2019). ...
Pastoral systems face increasing pressure from competing global markets, food sector industrialization, and new policies such as Europe’s post-2020 Common Agriculture Policy. This pressure threatens the use of extensive sheep-grazing systems in mountain areas of low productivity but high natural value. Using information gathered at a long-term research setting in a mountainous area of the Basque Country (northern Spain), we assessed the multiple benefits of extensive dairy sheep grazing systems from multiple perspectives using indicators pertaining to ecological, socio-economic, and food quality domains. In this way, we address the benefits that would be lost if sheep grazing abandonment persists in mountain regions. Our results show that the benefits of extensive dairy sheep grazing in the research area include the production of healthy and high-quality foods and multiple ecological benefits including biodiversity conservation. Extensive dairy sheep grazing also contributes to rural development by generating employment and income in marginal, low-productivity lands that can support few economic alternatives. In particular, we found that sheep farmers who produce high-value products, such as cheese, have enhanced their economic profitability and are less dependent on public subsidies. However, careful attention to sustainable practices, support for new generations of farmers, and streamlined supply chains are required. These would contribute to ensure socio-economic benefits for farmers, avoid the ecological costs associated with grazing abandonment, and enhance ecosystem services for the whole society.
... All ruminants produce methane and so have impacts on global warming, but in global assessments for climate change mitigation we are interested in those that are "additional." This means thinking about what the appropriate baseline is (Manzano & White, 2019). Emissions from industrial systems are clearly additional to a natural baseline. ...
The relationship between livestock production and climate change is the subject of hot debate, with arguments for major shifts in diets and a reduction in livestock production. This Perspective examines how global assessments of livestock‐derived methane emissions are framed, identifying assumptions and data gaps that influence standard life‐cycle analysis approaches. These include inadequate data due to a focus on industrial not extensive systems; errors arising due to inappropriate emission factors being applied; questions of how global warming potentials are derived for different greenhouse gases and debates about what baselines are appropriate. The article argues for a holistic systems approach that takes account of diverse livestock systems—both intensive and extensive—including both positive and negative impacts. In particular, the potential benefits of extensive livestock systems are highlighted, including supporting livelihoods, providing high‐quality nutrition, enhancing biodiversity, protecting landscapes, and sequestering carbon. By failing to differentiate between livestock systems, global assessments may mislead. Inappropriate measurement, verification and reporting processes linked to global climate change policy may in turn result in interventions that can undermine the livelihoods of extensive livestock‐keepers in marginal areas, including mobile pastoralists. In the politics of global assessments, certain interests promote framings of the livestock‐climate challenge in favour of contained, intensive systems, and the conversion of extensive rangelands into conservation investments. Emerging from a narrow, aggregated scientific framing, global assessments therefore can have political consequences. A more disaggregated, nuanced approach is required if the future of food and climate change is to be effectively addressed.
This article is categorized under: Integrated Assessment of Climate Change > Assessing Climate Change in the Context of Other Issues
Climate and Development > Social Justice and the Politics of Development
... Similarly, the disagreement among experts on the contribution of grazing practices to carbon sequestration is consistent with previous studies that observed lower expert knowledge on carbon sequestration dynamics (Rodríguez-Ortega et al., 2018). Recent studies signal the potential of well-managed livestock systems to increase soil carbon storage capacity, but the effects of grazing intensity, regimes, season and species are still understudied (Stanley et al., 2018;Manzano and White, 2019). Likewise, the mismatches in the scoring according to the expert category and specialization claims for a broader transdisciplinary approach. ...
Silvopastoral systems (SPS) emerge with a renewal interest in the Mediterranean for their promotion of multifunctionality through a variety of ecosystem services (ES). However, the understanding of how combined forestry and pastoral practices affect the ES delivery as well as the synergies and trade-off dynamics amongst them is still very limited. We applied the structured expert consultation Delphi method to assess the medium-term effect of relevant silvopastoral management practices (SMP) on the delivery of provision, regulation and maintenance and cultural ES in Mediterranean mid-mountain SPS in Spain. The deliberation process entailed two rounds and the Delphi panel was finally formed by 69 experts covering a broad spectrum of background and expertise. Results show that some practices, such as silvicultural treatments (e.g., thinning or coppice selection), play a multifunctional role contributing to ES delivery in bundles while some trade-offs are also identified between SMP, such as free animal grazing, and the provision of some ES. Synergies are also found between ES, such as livestock production and recreational hunting and between timber production and carbon sequestration, whereas possible trade-offs were particularly relevant between wildfire prevention and carbon sequestration. These findings can support decision-making processes towards sustainable and multifunctional silvopastoral management in the northern Mediterranean basin.
... The most characteristic systems are the pastoral and agropastoral systems in arid and semiarid areas based on feed grazing accompanied by herd mobility (Neely et al., 2009). Several recent research studies have established the comparative advantage of these grazing livestock systems, notably in facing global environmental challenges related to methane emission and other greenhouse gas emissions (Vigne et al., 2013;Manzano and White, 2019) and carbon sequestration (Reid et al., 2004). Overall these systems are considered the most sustainable systems in these constrained and fragile environments, as shown by Behnke (1994), Th� ebaud and Batterbury (2001), and recently by Nori and Farinella (2021). ...
Analyzing the sustainability of grazing livestock farming systems in the drylands at the farm and household or territorial levels (in terms of food security, well-being, value chain performance, feed supply, and maintenance of common grazing resources) constitutes a major challenge in the context of global changes. In particular, social–natural interdependency in an entanglement of spatial and temporal scales complicates the development of a common and systematic framework for assessing the sustainability of these grazing livestock systems. Our objective is to give an overview of some fundamental sets of indicators usually used and elaborate on some principles to guide the sustainable assessment of grazing livestock systems in drylands. To do so, this paper reviews a set of empirical, theoretical, and methodological studies related to the analysis of risk, adaptability, vulnerability, resilience, and sustainability of livestock systems in drylands based on grazing (mostly pastoral systems, but also some integrated crop-livestock systems). More concretely, this review seeks to compile a set of indicators to inform the processes of assessing the sustainability of livestock socio-ecosystems.
It points to the wide range of approaches that have been used to address the sustainability of grazing livestock systems, ranging from those that focus on ecological or social approaches to more integrated and systemic approaches; from indicator-based approaches to those focusing on processes; from quantitative approaches to those that point out the need to take qualitative aspects into consideration; and from research-based assessments to participatory approaches. Based on this review, we propose a multi-scale indicators framework combining scales of space, time, and coordination to address the sustainability of these livestock systems. This framework aims to constitute a sound basis for elaborating a system of information that will contribute to and support policymakers and development agencies in developing their policies and measurements in order to ensure the sustainable development of pastoral and agropastoral systems in the short and medium-term. However, this study also warns about the multiple contextual scopes of the indicators and their implications, which reveal differing dynamics (and therefore adaptive capacities) of these systems.
... Dans le contexte des changements globaux et d'incertitudes (catastrophes naturelles, zoonoses), le pastoralisme se positionne comme un système de production résilient et durable dans les systèmes socio-écologiques semi-arides (Leclerc et Sy, 2011 ;Manzano et White, 2019). Ce mode d'utilisation de l'espace est néanmoins sujet à plusieurs pressions et menaces, comme les changements climatiques (Simel, 2008 ;Hiernaux et al., 2014), la raréfaction des ressources fourragères (Traoré, 1997), le manque d'investissements publics dans l'accompagnement des systèmes pastoraux ou les politiques de gestion de l'espace minimisant la capacité de mouvement des troupeaux (Birch et Grahn, 2007), et les conflits avec d'autres modes d'utilisation de l'espace (Abbass, 2012 ;Butt et Turner, 2012 ;Butt, 2014). ...
In the context of global changes, pastoralism is positioned as a relevant production system in semi-arid areas. However, those ecosystems are particularly vulnerable face to global warming. It is now necessary to preserve them and think up flexible planning and management rules rooted in local socio-ecological realities. This article presents work carried out in the Ferlo (Sylvopastoral Zone), inhabited mainly by Fulani pastoralists. For more than half a century, the Ferlo has been the scene of constant development policies and projects accumulated around the management of pastoral resources and the fight against desertification. We defend the idea that difficulties in solving the socio-ecological challenges of the Ferlo come from project development implemented in this area are based on an obsolete narrative. Based on fieldwork and document analysis, we propose an update of this narrative, describing the socio-ecological transition of the Ferlo from the historical system of the hurum to a contemporary system characterized by great complexity. Throughout the article, we draw attention to the potential consequences of the discrepancy between the Ferlo as perceived by public authorities and development agents on the one hand and how Fulani pastoralists de facto use it.
... Dans le contexte des changements globaux et d'incertitudes (catastrophes naturelles, zoonoses), le pastoralisme se positionne comme un système de production résilient et durable dans les systèmes socio-écologiques semi-arides (Leclerc et Sy, 2011 ;Manzano et White, 2019). Ce mode d'utilisation de l'espace est néanmoins sujet à plusieurs pressions et menaces, comme les changements climatiques (Simel, 2008 ;Hiernaux et al., 2014), la raréfaction des ressources fourragères (Traoré, 1997), le manque d'investissements publics dans l'accompagnement des systèmes pastoraux ou les politiques de gestion de l'espace minimisant la capacité de mouvement des troupeaux (Birch et Grahn, 2007), et les conflits avec d'autres modes d'utilisation de l'espace (Abbass, 2012 ;Butt et Turner, 2012 ;Butt, 2014). ...
In the context of global changes, pastoralism is positioned as a relevant production system in semi-arid areas. However, those ecosystems are particularly vulnerable face to global warming. It is now necessary to preserve them and think up flexible planning and management rules rooted in local socio-ecological realities. This article presents work carried out in the Ferlo (Sylvopastoral Zone), inhabited mainly by Fulani pastoralists. For more than half a century, the Ferlo has been the scene of constant development policies and projects accumulated around the management of pastoral resources and the fight against desertification. We defend the idea that difficulties in solving the socio-ecological challenges of the Ferlo come from project development implemented in this area are based on an obsolete narrative. Based on fieldwork and document analysis, we propose an update of this narrative, describing the socio-ecological transition of the Ferlo from the historical system of the hurum to a contemporary system characterized by great complexity. Throughout the article, we draw attention to the potential consequences of the discrepancy between the Ferlo as perceived by public authorities and development agents on the one hand and how Fulani pastoralists de facto use it.
... For this reason, improving the efficiency in the use of this nutrient by ruminants may be a viable alternative not only to increase animal productivity but also to reduce GHG emissions by reducing N excretion. It must be noted however that in extensive grazing and pastoralist systems cattle can be undernourished, and the scarce nutrients can be used more effectively by animals (Manzano and White, 2019). ...
Cattle production systems are an important source of greenhouse gases (GHG) emitted
to the atmosphere. Animal manure and managed soils are the most important sources
of emissions from livestock after enteric methane. It is estimated that the N2O and CH4
produced in grasslands and manure management systems can contribute up to 25%
of the emissions generated at the farm level, and therefore it is important to identify
strategies to reduce the fluxes of these gases, especially in grazing systems where
mitigation strategies have received less attention. This review describes the main factors
that affect the emission of GHG from manure in bovine systems and the main strategies
for their mitigation with emphasis on grazing production systems. The emissions of N2O
and CH4 are highly variable and depend onmultiple factors, whichmakes it difficult to use
strategies that mitigate both gases simultaneously. We found that strategies such as the
optimization of the diet, the implementation of silvopastoral systems and other practices
with the capacity to improve soil quality and cover, and the use of nitrogen fixing plants
are among the practices with more potential to reduce emissions from manure and at the
same time contribute to increase carbon capture and improve food production. These
strategies can be implemented to reduce the emissions of both gases and, depending
on the method used and the production system, the reductions can reach up to 50%
of CH4 or N2O emissions from manure according to different studies. However, many
research gaps should be addressed in order to obtain such reductions at a larger scale.
... Ces niveaux de référence sont utilisés en climatologie en général, dans des aspects si fondamentaux comme le niveau de vapeur d'eau (qui est de loin le gaz à effet de serre le plus important -et heureusement, car notre planète ne serait autrement pas habitable). Il est nécessaire d'examiner quelles options de niveaux de référence nous devrions utiliser également pour les impacts de l'élevage, et c'est ce que j'ai évoqué dans une publication récente (Manzano & White 2019). Ici, notre connaissance de l'Afrique nous explique que le modèle de paysage naturel est basé sur des paysages dominés par des herbivores, soit des bisons et des cervidés avant l'arrivée des Européens (Hristov 2012), soit des mégaherbivores, en Amérique du Nord (Smith et al 2010) ou en Sibérie (Zimov & Zimov 2014) avant leur disparition. ...
L'utilisation de niveaux de référence est courante dans les études scientifiques de disciplines diverses, y compris l'environnement, mais elles dépendent de la référence géographique ou historique considérée. La mesure des effets de l'élevage sur le changement climatique a toutefois négligé cet aspect. En effet, les émissions de gaz à effet de serre sont rarement considérées dans un contexte écologique. Les systèmes de ruminants nourris à l'herbe sont perçus comme de forts émetteurs de méthane, et, pour cette raison uniquement, il est peut-être recommandé de les convertir en systèmes intensifs de poulet et de porc nourris au grain.
Nous avons examiné la littérature existante sur les émissions de gaz à effet de serre des ruminants sauvages, en tenant également compte du rôle potentiel des termites, susceptibles de remplacer les niches d'herbivores dans un scénario sans ongulés. Les scénarios de référence naturels seraient du même ordre de grandeur que les scénarios actuels d’élevage. Les recommandations politiques actuelles sur le changement dans le secteur de l'élevage risquent donc d'être beaucoup moins efficaces qu'on ne le pense actuellement. Des considérations similaires peuvent être appliquées sur les impacts de l'élevage sur l'eau ou la biodiversité. Les recommandations politiques devraient prendre en compte les niveaux de référence, se concentrer sur la réduction de l'utilisation intensive de combustibles fossiles et sur des stratégies de réduction du méthane ayant des bénéfices sociales, telles que l'utilisation de fourneaux de cuisson au biogaz alimentés au fumier.
... Sí se usan en ciencia climática en general, en aspectos tan fundamentales como que el vapor de agua es, con mucho, el gas de mayor efecto invernadero -y afortunadamente, porque nuestro planeta de otro modo no sería habitable. Es necesario plantear qué escenarios de niveles de referencia debemos usar también para los impactos de la ganadería (Manzano & White 2019). Aquí África nos dice que el escenario natural contempla paisajes dominados por herbívoros, bien bisontes y cérvidos a la llegada de los europeos (Hristov 2012) o bien antes de que desaparecieran los megaherbívoros, en Norteamérica (Smith et al 2010) o en Siberia (Zimov & Zimov 2014). ...
La alpaca (Vicugna pacos) es un mamífero artiodáctilo de la familia Camelidae. Digestivamente es considerado un pseudo-rumiante, produciendo metano durante el proceso digestivo. En el mundo existen alrededor de 4.1 millones de alpacas que son criadas para producir fibra la cual se considera de alta calidad. En el Perú se cría el 87% de la población mundial de alpacas. Su crianza se desarrolla en sistemas extensivos de pastoreo en pastizales altoandinos (>4000 msnm) a cargo de 82 mil familias rurales. La crianza de alpacas enfrenta bajos niveles de productividad y escaso desarrollo de capital y tecnología, como tal sus criadores se encuentran en condiciones de pobreza y pobreza extrema por los bajos precios de su fibra y carne.
Los pastizales altoandinos cumplen un rol fundamental en el ciclo hidrológico y se constituyen en sumideros de carbono, un pastizal tipo Chilliwar captura 7.1 t C por ha año. Por otro lado, se ha estimado que la producción de metano entérico de las alpacas en pastoreo se aproxima a 8 kg CH4 por animal año. En esta situación aún es escasa la información que existe respecto a la huella de carbono de la producción alpaquera en sistemas de producción tradicionales y
condiciones ambientales altoandinas. En el presente estudio se ha realizado un balance de CO2 para un sistema de producción de alpacas en pastoreo extensivo. Para ello se ha utilizado un caso de estudio en un pastizal altoandino “Chilliwar” de 50 has, con un hato de 100 alpacas madres con sus unidades acompañantes (machos reproductores, crías de 1 año, crías de 2 años y animales de reposición), manejado por una familia campesina. Los productos finales de este sistema son la fibra y la carne de alpaca. Se ha calculado la huella de carbono para los productos fibra y carne de alpaca. La única fuente de alimento para las alpacas es el propio pastizal, no existiendo insumos externos. Se ha estimado que, el pastizal altoandino captura 355 t de CO2 año, las alpacas consumen en forma de forraje 224 t de CO2 año. De otra parte, la población de
alpacas, considerando las emisiones de CH4, emite 41.4 t de CO2-eq al año y la familia de pastores, por sus condiciones de vida y manejo tecnológico, conlleva una emisión 29.49 t de CO2-eq (mano de obra para actividades de pastoreo, esquila y otras actividades de sanidad y
manejo ganadero). El balance anual del sistema estudiado es negativo (-60 t de CO2), resultando, la huella de carbono para los productos del sistema en -61.5 kg CO2-eq/kg de fibra y -22.3 kg CO2-eq/kg de carne. Por lo tanto, según los resultados de este caso de estudio, la crianza de alpacas en sistemas de producción tradicional en los andes puede considerarse un sumidero de carbono a corto y medio plazo. Este resultado presenta la posibilidad para mejorar el valor económico de la fibra y carne de alpaca en beneficio de las familias rurales alpaqueras.
... Other research has considered the effects of rewilding, the effect of moving away from pastoralism toward more dense production using concentrates and grain. When nonlivestock animals, such as nondomesticated ruminants and termites, move into areas previously used by livestock, there is a significant effect on GHGE (Manzano and White, 2019). As such, understanding what role dairy products, specifically, play in the US agricultural system and the nutritional and environmental impacts associated with removing dairy production would be of use in assessing dairy production's utility in the US food production system. ...
Questions regarding the balance between the contribution to human nutrition and the environmental impact of livestock food products rarely evaluate specific species or how to accomplish the recommended depopulation. The objective of this study was to assess current contributions of the US dairy industry to the supply of nutrients and environmental impact, characterize potential impacts of alternative land use for land previously used for crops for dairy cattle, and evaluate the impacts of these approaches on US dairy herd depopulation. We modeled 3 scenarios to reflect different sets of assumptions for how and why to remove dairy cattle from the US food production system coupled with 4 land-use strategies for the potential newly available land previously cropped for dairy feed. Scenarios also differed in assumptions of how to repurpose land previously used to grow grain for dairy cows. The current system provides sufficient fluid milk to meet the annual energy, protein, and calcium requirements of 71.2, 169, and 254 million people, respectively. Vitamins supplied by dairy products also make up a high proportion of total domestic supplies from foods, with dairy providing 39% of the vitamin A, 54% of the vitamin D, 47% of the riboflavin, 57% of the vitamin B12, and 29% of the choline available for human consumption in the United States. Retiring (maintaining animals without milk harvesting) dairy cattle under their current management resulted in no change in absolute greenhouse gas emissions (GHGE) relative to the current production system. Both depopulation and retirement to pasture resulted in modest reductions (6.8–12.0%) in GHGE relative to the current agricultural system. Most dairy cow removal scenarios reduced availability of essential micronutrients such as α-linolenic acid, Ca, and vitamins A, D, B12, and choline. Those removal scenarios that did not reduce micronutrient availability also did not improve GHGE relative to the current production system. These results suggest that removal of dairy cattle to reduce GHGE without reducing the supply of the most limiting nutrients to the population would be difficult.
... Sin embargo, también pueden ser empleados para calcular de manera más precisas las emisiones asociadas a la producción de materias primas para alimentación animal, que no ha sido posible incorporar al presente trabajo debido a que estos documentos se han terminado de publicar cuando el proyecto había finalizado. Este estudio más detallado de la producción ganadera también podría incluir análisis de niveles de base de emisiones 229,230 en ausencia de animales domésticos, para calcular emisiones de sistemas ganaderos vinculados al territorio en comparación con otros más intensivos. ...
La “huella de carbono” expresa, en términos de CO2 equivalentes (CO2e), la cantidad de GEI emitida y carbono capturado en la elaboración de un producto o servicio. En este trabajo se ha estimado la huella de carbono del sistema agroalimentario y de la alimentación de la población residente en España, contabilizando de manera pormenorizada las emisiones de GEI que se generan no solo en campos de cultivo y granjas, sino también las que ocurren “aguas arriba” de la explotación, por ejemplo, durante la fabricación de los insumos agrícolas como fertilizantes y la producción de electricidad, o la producción de materias primas importadas para la producción de piensos (y deforestación asociada), así como de la gestión de residuos alimentarios. Para ello se ha empleado el Análisis de Ciclo de Vida (ACV), una metodología que, desde hace años, cuenta con un amplio respaldo dentro de la comunidad científica. Se consideran además 3 cortes temporales para el análisis de la evolución temporal de las emisiones del sistema agroalimentario en su conjunto: 1960, 1985 y 2010, mientras que en el caso de la producción de cultivos se estudian 4 cortes: 1900, 1960, 1990 y 2016.
... Sí se usan en ciencia climática en general, en aspectos tan fundamentales como que el vapor de agua es, con mucho, el gas de mayor efecto invernadero -y afortunadamente, porque nuestro planeta de otro modo no sería habitable. Es necesario plantear qué escenarios de niveles de referencia debemos usar también para los impactos de la ganadería (Manzano & White 2019). Aquí África nos dice que el escenario natural contempla paisajes dominados por herbívoros, bien bisontes y cérvidos a la llegada de los europeos (Hristov 2012) o bien antes de que desaparecieran los megaherbívoros, en Norteamérica (Smith et al 2010) o en Siberia (Zimov & Zimov 2014). ...
Los pastizales altoandinos cumplen un rol fundamental en el ciclo hidrológico y se constituyen en sumideros de carbono, un pastizal tipo Chilliwar captura 7.1 t C por ha año. Por otro lado, se ha estimado que la producción de metano entérico de las alpacas en pastoreo se aproxima a 8 kg CH4 por animal año. En esta situación aún es escasa la información que existe respecto a la huella de carbono de la producción alpaquera en sistemas de producción tradicionales y condiciones ambientales altoandinas. En el presente estudio se ha realizado un balance de CO2 para un sistema de producción de alpacas en pastoreo extensivo. Para ello se ha utilizado un caso de estudio en un pastizal altoandino “Chilliwar” de 50 has, con un hato de 100 alpacas madres con sus unidades acompañantes (machos reproductores, crías de 1 año, crías de 2 años y animales de reposición), manejado por una familia campesina. Los productos finales de este
sistema son la fibra y la carne de alpaca. Se ha calculado la huella de carbono para los productos fibra y carne de alpaca. La única fuente de alimento para las alpacas es el propio pastizal, no existiendo insumos externos. Se ha estimado que, el pastizal altoandino captura 355 t de CO2 año, las alpacas consumen en forma de forraje 224 t de CO2 año. De otra parte, la población de alpacas, considerando las emisiones de CH4, emite 41.4 t de CO2-eq al año y la familia de pastores, por sus condiciones de vida y manejo tecnológico, conlleva una emisión 29.49 t de CO2-eq (mano de obra para actividades de pastoreo, esquila y otras actividades de sanidad y manejo ganadero). El balance anual del sistema estudiado es negativo (-60 t de CO2), resultando, la huella de carbono para los productos del sistema en -61.5 kg CO2-eq/kg de fibra y -22.3 kg CO2-eq/kg de carne. Por lo tanto, según los resultados de este caso de estudio, la crianza de alpacas en sistemas de producción tradicional en los andes puede considerarse un sumidero de carbono a corto y medio plazo. Este resultado presenta la posibilidad para mejorar el valor económico de la fibra y carne de alpaca en beneficio de las familias rurales alpaqueras.
... Arguments against red meat production rest on the assumption that if grazing ruminants are removed and the meat required is provided through intensive livestock systems (nonred meat), greenhouse gas (GHG) emissions will be reduced. However, the current paradigm for mitigating the effects of climate change by promoting intensive meat production from monogastric animals may be misleading [5]. In fact, in the absence of grazing by farmed ruminants, rangeland habitats may be dominated by other methane-producing herbivores including roe deer, elk, and reindeer. ...
Norway has vast rangeland resources (292,361 km2) with an estimated carrying capacity of nearly four million sheep and lambs, twice the current number. However, the intensive production system currently applied has led to more concentrate dependency, resulting in heavier animals in addition to poorer utilization of rangelands and homegrown feed. Intensive feeding systems indirectly influence the sustainability of ecosystems by promoting intensive cropping that can deplete soil fertility and threaten landscape preservation and biodiversity. By contrast, extensive grazing systems can produce environmentally and animal-friendly food products and contribute to regulating soil health, water and nutrient cycling, soil carbon sequestration, and recreational environments. In this paper, the economics of current sheep feeding practices in Norway, using a linear programming model, were compared with more extensive systems which allow for higher usage of on-farm feed resources. Changes in current sheep farming practices have the potential to increase lamb meat production relative to mutton production, in addition to improving the year-round supply of fresh meat. The investigated alternatives, using the Norwegian White Sheep (NWS) breed, suggest that delayed lambing is useful only on farms with abundant pastures available for autumn feeding. Lambs achieve a better market price than hoggets and mature sheep. Therefore, based on the current Norwegian meat market and price offered per kilogram of meat for lamb, an increase in NWS lamb production improves farm profits. On the other hand, when the aim is on greater use of homegrown feed and rangelands, this can be achieved through hogget production, and the quantity of concentrates required can be reduced substantially.
... Arguments against red meat production rest on the assumption that if grazing ruminants are removed and the meat required is provided through intensive livestock systems (nonred meat), greenhouse gas (GHG) emissions will be reduced. However, the current paradigm for mitigating the effects of climate change by promoting intensive meat production from monogastric animals may be misleading [5]. In fact, in the absence of grazing by farmed ruminants, rangeland habitats may be dominated by other methane-producing herbivores including roe deer, elk, and reindeer. ...
Norway has vast rangeland resources (292,361 km2) with an estimated carrying capacity of nearly four million sheep and lambs, twice the current number. However, the intensive production system currently applied has led to more concentrate dependency, resulting in heavier animals in addition to poorer utilization of rangelands and homegrown feed. Intensive feeding systems indirectly influence the sustainability of ecosystems by promoting intensive cropping that can deplete soil fertility and threaten landscape preservation and biodiversity. By contrast, extensive grazing systems can produce environmentally and animal-friendly food products and contribute to regulating soil health, water and nutrient cycling, soil carbon sequestration, and recreational environments. In this paper, the economics of current sheep feeding practices in Norway, using a linear programming model, were compared with more extensive systems which allow for higher usage of on-farm feed resources. Changes in current sheep farming practices have the potential to increase lamb meat production relative to mutton production, in addition to improving the year-round supply of fresh meat. The investigated alternatives, using the Norwegian White Sheep (NWS) breed, suggest that delayed lambing is useful only on farms with abundant pastures available for autumn feeding. Lambs achieve a better market price than hoggets and mature sheep. Therefore, based on the current Norwegian meat market and price offered per kilogram of meat for lamb, an increase in NWS lamb production improves farm profits. On the other hand, when the aim is on greater use of homegrown feed and rangelands, this can be achieved through hogget production, and the quantity of concentrates required can be reduced substantially.
... Es cierto que la ganadería extensiva utiliza ciclos de vida más largos y que los animales, al moverse y estar en el exterior utilizan El argumento de la línea base de emisiones es muy interesante para la ganadería extensiva. Hay dos referencias clave para desarrollarlo, el artículo científico en el que Manzano y White exponen el fundamento de esta argumentación: Manzano & White (2019). Intensifying pastoralism may not reduce greenhouse gas emissions: wildlife-dominated landscape scenarios as a baseline in life-cycle analysis. ...
Este cuaderno, coeditado por la Fundación Entretantos y la Plataforma por la Ganadería Extensiva y el Pastoralismo, recopila y organiza un intenso trabajo colectivo desarrollado en el seno de la Plataforma para abordar la adaptación y la lucha contra el cambio climático desde la perspectiva de la ganadería extensiva. El proceso se inició con una serie de debates en el seno de la Plataforma sobre el papel climático de la ganadería extensiva, sus emisiones, sus necesidades de adaptación y su potencial de mitigación. Estos debates fueron incorporando experiencias, artículos científicos (varios de ellos firmados por las mismas personas que debatían), prácticas innovadoras (planteadas desde la realidad de ganaderos y ganaderas en activo) y propuestas políticas que comparten una idea global: la necesidad de cambiar radicalmente, tanto a nivel técnico como científico y político, la visión actual de la relación entre cambio climático y ganadería extensiva. La riqueza de este debate y de las ideas aportadas nos animaron a presentarlas en la pasada reunión de la COP25, en Madrid. Esta presentación se organizó, de forma colaborativa, en torno a una mesa redonda en la que participaban, simultáneamente, personas vinculadas al mundo científico, investigadoras, activistas y, por supuesto, ganaderos y ganaderas. La fotografía de esta mesa redonda describe igualmente la forma de trabajo y el espíritu colectivo que constituyen la principal seña de identidad de la Plataforma. El paso siguiente consistía en transmitir estas ideas al resto de la sociedad, de forma que el cambio de perspectiva pudiera adoptarse de forma mucho más amplia, sobre todo entre las personas y organizaciones que trabajan alrededor de la ganadería, la agricultura y la alimentación. Así surge la iniciativa de editar y distribuir este cuaderno. El cuaderno organiza nuevas y viejas ideas, todas ellas con un sólido fundamento científico detrás. Se trata de un documento técnico, pero que se ha intentado hacer más comprensible y accesible a cualquier persona interesada, separando las ideas principales de una serie de materiales complementarios. Así, aunque el texto principal está escrito en tono divulgativo y accesible, el cuaderno incluye numerosos recuadros en los que se describen y enlazan artículos científicos, informes y documentos técnicos, en castellano o en inglés, que permiten fundamentar los contenidos y elaborar discursos propios. Sintetizando, se trata de desplegar la enorme capacidad que la ganadería extensiva tiene de cara a hacer más sostenible y segura nuestra producción de alimentos en el contexto actual de cambio climático, y también su aportación insustituible para adaptarnos y reducir los efectos de dicho cambio.
... It is important to generate truthful and objective information on the contribution of ruminant livestock systems to climate change. Although it is true that ruminants produce large amounts of methane from enteric fermentation -ruminants are blamed for 80% of the greenhouse gases emissions (GHG) in livestock systems-it is likewise true that grazing can increase carbon sequestration and compensate for emissions (Manzano & White, 2019). On the other hand, most publications related to GHG emissions from ruminants refer to feedlots where animals feed on cultivated grasslands, which is very different from the use of natural grazable resources produced in Mediterranean ecosystems with low use of non-renewable energy. ...
Aim of study: To characterize and analyse the extensive livestock farming systems in environmental protected area and propose strategies for their sustainable improvement.
Area of study: Sierra Nevada Protected Area (Spain)
Material and methods: Data were collected from a sample of 85 farmers and 48 experts. The information from farmers was expressed in 35 variables, 23 of which were qualitative and 12 quantitative. A multivariate analysis was conducted.
Main results: The principal components explained 71.2% of the total variance and the k-means cluster analysis identified three groups: C1 (38 farms), medium-size farms with a predominance of goats and relative dairy specialization; C2 (12 farms), large-size farms with extensive grazing lands, a high proportion of meat purpose animals and managed by young and dynamic farmers and C3 (35 farms), medium-size farms with a high proportion of meat purpose animals and undeveloped business management. The main problems reported were: insufficient pastures for livestock, stagnation of product prices, lack of generational renewal and need for social recognition of livestock farming. These obstacles could be overcome by implementing measures aimed at improving feed self-sufficiency -and thus reduce production costs- increasing income through social recognition of farming, achieving product differentiation, and strengthening short marketing channels. This would be favoured by an increase in associationism and specialized training.
Research highlights: Farm management and marketing are important for improve these farming systems. The extensive livestock farming continues to be an important activity in European protected mountain areas.
KEY MESSAGES
1. As global temperatures continue to increase, food systems are facing a double burden. While emitting over one third of global green-house gases, they are jeopardized by climate change at the same time. Increasing energy inputs to stabilize production from rising climate variability also increases global warming. A fundamental rehaul of global food systems is needed with an alternative approach to climate resilience, with low emission strategies at the core.
2. Resilience to climate change is conditional to avoiding catastrophic global warming. ‘Resilience in the face of climate change’ refers to the unprecedented climate variability humanity will have to live with even if global warming is limited to 1.5°C and does not trigger a tipping point in one or more of Earth’s natural systems. Therefore, today’s resilience to climate change is only sustainable if it does not depend on the energy-intensive processes that have set the world on the current trajectory to runaway climate change.
3. Variability in the ways of operating, especially mobility, is crucial to pastoralists’ adaptive capacity. Pastoralists’ resilience while making use of unpredictable environments is based on keeping options open. Variability is embedded in operational pro- cesses and institutional arrangements so that they can be rapidly adapted to short-notice changes in the external conditions. Mobility remains pivotal to this logic.
4. Addressing non-climate stressors is key also to 4 climate resilience. The analysis of climate vulnerability in pastoralism and small-scale agricultural systems, and the strategies to reduce it, must engage with non-climate stressors, as they are generally the primary cause of climate vulnerability. Promoting climate resilience starts from removing the legacy of non-climate stressors that undermine it.
5. Smallholder farmers’ livelihood systems in drylands can learn from pastoralism to address the challenge of sustainably producing food in an increasingly unpredictable climate. Small-scale rainfed agricultural systems, and especially pastoralism, might be the world’s best bet in the face of the imperative to avoid catastrophic climate change while securing resilience. Pastoralism shows that resilience in the face of climate variability is possible even without the energy intensive solutions that keep the planet on the current trajectory to a climate catastrophe. Today, this lesson
has relevance well beyond pastoralism and the dry-lands.
Knowing the carrying capacity of the Earth’s grazed ecosystems, and the relevance of herbivory, is important for many scientific disciplines, as well as for policy. Current herbivore levels are estimated to be four to five times larger than at the Pleistocene–Holocene transition or the start of the industrial revolution. While this estimate can lead the general public and the scientific community to predict severe, widespread environmental impacts by livestock in terms of deforestation, biodiversity loss, and climate change, it ignores the inherent uncertainty of such calculations. We revise the evidence published during the last decade regarding Late Pleistocene herbivore abundance, along with contemporary and some pre-industrial data on herbivore density in grazed ecosystems. Both Late Pleistocene and pre-industrial herbivore levels are likely to be consistently higher than what has generally been assumed, confirming increasing awareness on the importance of herbivory as a widespread ecological process. We therefore call for more refined research in this field to have the reliable baselines currently demanded by society and policy. These baselines should orient sound action toward policies on biodiversity conservation, ecosystem restoration, food systems, and climate change.
This issue of the IDS Bulletin brings together a range of empirically grounded studies that add to – and challenge – contemporary debates on climate and environmental justice. Despite a growing focus on justice dimensions of climate and environmental change, we argue that there are still ‘blind spots’ in mainstream debates that warrant increased attention. In this brief introduction, we point to three in particular: first, a persistent failure to recognise diverse contexts and knowledges; second, a continuing failure to sufficiently appreciate the deep-seated contestations around climate and environmental justice; and third, the risks associated with ‘recovery’ and ‘emergency’ mindsets driving climate and environmental policy agendas. The articles in this collection illustrate and exemplify these issues in different ways and from a variety of methodological, philosophical, and interdisciplinary approaches and positionalities. We argue for a reframing of climate and environmental justice debates and suggest some key principles to make these ‘hidden’ aspects more visible in policy and practice.
In discussions around food systems and the climate, livestock is often painted as the villain. While some livestock production in some places contributes significantly to climate change, this is not universally the case. This article focuses on pastoral production systems – extensive, often mobile systems using marginal rangelands across around half of the world’s surface, involving many millions of people. By examining the assumptions behind standard calculations of greenhouse gas emissions, a systematic bias against pastoralism is revealed. Many policy and campaign stances fail to discriminate between different material conditions of production, lumping all livestock systems together. Injustices arise through the framing of debates and policy knowledge; through procedures that exclude certain people and perspectives; and through the distributional consequences of policies. In all cases, extensive livestock keepers lose out. In reflecting on the implications for European pastoralism, an alternative approach is explored where pastoralists’ knowledge, practices, and organisations take centre stage.
Trees in dryland forests and wooded areas provide key ecosystem services such as animal feed, timber, fruits and, regulation of soil and water cycles. Equally, the presence of livestock in dryland woody areas can also play an important role in the local ecosystem; not only are they a source of income for local communities, but they also help vegetation and mobilise stored biomass. When both of these ecosystem elements are wisely combined – livestock and trees – it creates an integrated agricultural system that can boost the local ecosystem, representing a welcome agro-ecological transition in livestock farming. The ‘Grazing with Trees’ report gives a thorough assessment of the positive role that optimized extensive grazing livestock farming can play in the management and restoration of drylands’ forests and lands with trees. It assesses and provides sound evidence on the benefits of applying an integrated landscape approach and utilizing farmers and pastoralists’ knowledge to halt desertification, increase resilience, and enhance food security under the actual changing scenario. The report confirms the importance of agroforestry as a primary pathway for forest restoration in dryland areas as recommended by FAO’s State of Forests 2022, and its recommendations encourage landscape planners and decision makers to consider livestock as allies, carefully restore tree cover and accelerate action to promote healthy ecosystems.
Although grasslands have an extensive global coverage and are important contributors to fodder production, they have received less attention as providers of multiple ecosystem services (ES). In this paper, we investigate the utility of the ES framework for grassland management in Europe. We focus on semi-natural grasslands (SNG) and improved grasslands (IG); both are widespread in European
agriculture. We present an overview of the ES delivered by these two grassland types and their potential synergies, trade-offs and bundles. We show that SNG are able to generate a wider range of ES than IG, and that trade-offs between ES exist in both grassland types. For example, SNG are good in providing
habitat for biodiversity, pollination, biological control and cultural services, but are poorer in biomass production and for increasing water infiltration, whereas IG produce higher quantities of biomass for fodder but contribute less to cultural services. Both IG and SNG are likely needed for the long-term sustainability of food production, but a larger effort towards landscape-scale management is needed to balance the provision of ES. Applying the ES concept to grasslands in farming systems could be valuable if used in an informed way, leveraging ecologically and economically grassland management for sustainable
livestock farming systems in Europe
Purpose Transhumance has rarely been analyzed through LCA approaches, and there is little evidence about its emissions level when conducted under different practices (by truck or on hoof), or compared to static/sedentary livestock systems. Moreover, mobile pastoralism is strongly linked to natural resources by its seasonal grazing patterns, thereby occupying the niche of wild herbivores. Considering natural emission baselines in these ecosystems could have relevant effects when estimating their carbon footprint.
Materials and methods Inventory data of 21 sheep farms was collected in order to estimate the carbon footprint (CF) of lamb meat produced. Farms were divided in 3 sub-groups representing typical management practices in the region: i) static (STAT), ii) transhumance by truck (THT) and iii) transhumance on hoof (THH). Livestock GHG emissions were modelled according to herd structure and IPCC guidelines. Off-farm emissions from external feeds and fuels were accounted based on existent LCA databases. A natural baseline of wild herbivores was established from the population of red deer reported in a hunting preserve, previously considered to be a reference for the natural carrying capacity in Mediterranean ecosystems. GHG emissions of wild herbivores were estimated through two methods based on: i) IPCC guidelines, and ii) allometric regression equations.
Results and discussion Carbon footprint ranged from 16.4 up to 30.6 kgCO2eq per kg of lamb liveweight (LW). Significant differences were identified among static and transhumant farms, which consistently showed lower CF values (STAT: 26.3 kgCO2eq/kg LW, THT: 18.1 kg CO2eq/kg LW, THH: 18.1 kg CO2eq/kg LW). Static farms resulted in higher GHG emissions (+31%) and higher CO2 and N2O, contributions derived from the consumption of additional feeds. Both methods applied to compute emissions for wild herbivores led to similar results (25.3-26.8 Mg CO2eq/km²), comparatively lower than estimation for transhumant sheep (47.7 Mg CO2eq/km²). When considering natural baseline emissions, the CF of transhumant lamb meat is reduced by almost 30%, reaching values quite below those reported for intensive lamb production systems in Spain.
Conclusions From our results, mobility of grazing livestock can be considered as a strategy promoting climate change mitigation. This is achieved mainly by reducing the need of external feeds, while maximizing the use of local forage resources that otherwise would be difficult to valorize. Further reductions in the CF result when considering natural baseline emissions. The application of this new GHG accounting perspective could have relevant implications when aiming at climate neutrality of grazing-based ruminant systems.
Animal source foods are evolutionarily appropriate foods for humans. It is therefore remarkable that they are now presented by some as unhealthy, unsustainable, and unethical, particularly in the urban West. The benefits of consuming them are nonetheless substantial, as they offer a wide spectrum of nutrients that are needed for cell and tissue development, function, and survival. They play a role in proper physical and cognitive development of infants, children, and adolescents, and help promote maintenance of physical function with ageing. While high-red meat consumption in the West is associated with several forms of chronic disease, these associations remain uncertain in other cultural contexts or when consumption is part of wholesome diets. Besides health concerns, there is also widespread anxiety about the environmental impacts of animal source foods. Although several production methods are detrimental (intensive cropping for feed, overgrazing, deforestation, water pollution, etc.) and require substantial mitigation, damaging impacts are not intrinsic to animal husbandry. When well-managed, livestock farming contributes to ecosystem management and soil health, while delivering high-quality foodstuffs through the upcycling of resources that are otherwise non-suitable for food production, making use of marginal land and inedible materials (forage, by-products, etc.), integrating livestock and crop farming where possible has the potential to benefit plant food production through enhanced nutrient recycling, while minimising external input needs such as fertilisers and pesticides. Moreover, the impacts on land use, water wastage, and greenhouse gas emissions are highly contextual, and their estimation is often erroneous due to a reductionist use of metrics. Similarly, whether animal husbandry is ethical or not depends on practical specificities, not on the fact that animals are involved. Such discussions also need to factor in that animal husbandry plays an important role in culture, societal well-being, food security, and the provision of livelihoods. We seize this opportunity to argue for less preconceived assumptions about alleged effects of animal source foods on the health of the planet and the humans and animals involved, for less top-down planning based on isolated metrics or (Western) technocratic perspectives, and for more holistic and circumstantial approaches to the food system.
Sustainability discussions bring in multiple competing goals, and the outcomes are often conflicting depending upon which goal is being given credence. The role of livestock in supporting human well-being is especially contentious in discourses around sustainable diets. There is considerable variation in which environmental metrics are measured when describing sustainable diets, although some estimate of the greenhouse gas (GHG) emissions of different diets based on varying assumptions is commonplace. A market for animal-free and manufactured food items to substitute for animal source food (ASF) has emerged, driven by the high GHG emissions of ASF. Ingredients sourced from plants, and animal cells grown in culture are two approaches employed to produce alternative meats. These can be complemented with ingredients produced using synthetic biology. Alternative meat companies promise to reduce GHG, the land and water used for food production, and reduce or eliminate animal agriculture. Some CEOs have even claimed alternative meats will 'end world hunger'. Rarely do such self-proclamations emanate from scientists, but rather from companies in their efforts to attract venture capital investment and market share. Such declarations are reminiscent of the early days of the biotechnology industry. At that time, special interest groups employed fear-based tactics to effectively turn public opinion against the use of genetic engineering to introduce sustainability traits, like disease resistance and nutrient fortification, into global genetic improvement programs. These same groups have recently turned their sights on the 'unnaturalness' and use of synthetic biology in the production of meat alternatives, leaving agriculturists in a quandary. Much of the rationale behind alternative meats invokes a simplistic narrative, with a primary focus on GHG emissions, ignoring the nutritional attributes and dietary importance of ASF, and livelihoods that are supported by grazing ruminant production systems. Diets with low GHG emissions are often described as sustainable, even though the nutritional, social and economic pillars of sustainability are not considered. Nutritionists, geneticists, and veterinarians have been extremely successful at developing new technologies to reduce the environmental footprint of ASF. Further technological developments are going to be requisite to continuously improve the efficiency of animal source, plant source, and cultured meat production. Perhaps there is an opportunity to collectively communicate how innovations are enabling both alternative- and conventional-meat producers to more sustainably meet future demand. This could counteract the possibility that special interest groups who promulgate misinformation, fear and uncertainty, will hinder the adoption of technological innovations to the ultimate detriment of global food security.
Exploring and developing new tools for the accounting and management of natural C sinks will provide a closer, more accurate option to remark the importance of such sinks in relation to livestock production, helping to support the persistence of some seriously endangered traditional, environmentally sustainable livestock farming. Following both precision and usability criteria, two main C sink databases covering the Andalusian region (S Spain) were developed from the Spanish Land Parcel Identification System (SIGPAC, coarse resolution) and the Spanish Information System on Land Cover (SIOSE, finer resolution) land use classes. Particular C sink factors based on growth rates for individual plant species were associated with detailed vegetation maps and, further, were linked to Land Use and Covers cartography across the region. In addition, eight ruminant farms were exhaustively studied in situ and used as a control. Results were compared with the obtained through the application of the developed C sink databases, and with the commonly used Petersen methodology. The sink capacity of vegetation associated with farms varied from 0.25 to 1.37 t CO2 ha−1 year−1, depending on the plant species composition and abundance. All the approaches showed significant differences from the control. C sink values were significantly higher when applying SIGPAC-based C sink database to farms, while values from the SIOSE and Petersen methodology approaches provided more moderate values, closer to the control. SIGPAC and Petersen approaches showed higher usability but presented lower precision due to a poor definition of plant cover. SIOSE-based C sink database provided suitable values able to be adapted to reality and used by farmers. In this regard, further research efforts to improve the adjustment of results and ease of use are required. The present approach means a methodological advance in the estimation of the C sink capacity associated with pastoral livestock farms, able to be incorporated into the CF calculation in contrasted areas worldwide, in the frame of the ‘eco-schemes’ being recently under development through the EU CAP.
Alternative systems for Norwegian sheep production: extending fresh meat season and meeting niche market demands Alternative system for norsk saueproduksjon: Utviding av fersk-kjøt-sesongen og fylling av marknadsnisjer Alternative systems for Norwegian sheep production: extending fresh meat season and meeting niche market demands Alternative system for norsk saueproduksjon: Utviding av fersk-kjøt-sesongen og fylling av marknadsnisjer Philosophiae Doctor (PhD) Thesis
This report intends to address the role that extensive farming can play in the context
of climate change, both in connection with improving the assessment of its emissions
and their derived effects, as well as contributing to its adaptation, and above all,
harnessing all its potential to fight climate change.
This report is conceived as a technical guide to raise awareness on the main arguments
that connect extensive farming to climate change, while providing access to abundant
sources and reports. To this end, highlighted boxes appear interspersed in the text,
referring to relevant technical or scientific publications related to the aspects addressed in each section.
Livestock production systems in West Africa are fundamental for food security and for sustaining rural economies. A review of the environment, its distribution, genetics, production systems, inputs, animal health, outputs, trade, policies, roles and constraints drives to a series of recommendations for the future
El pastoreo es un modelo de producción ganadera así como una forma de vida con importantes implicaciones sobre los territorios rurales a escala global. Sin embargo, el declive de los sistemas de explotación tradicionales y su conversión en formatos intensivos e industrializados ha abierto el debate sobre la sostenibilidad del sector ganadero. Por este motivo, las políticas públicas se han visto obligadas a elaborar estrategias y normativas que reconozcan los servicios prestados por el pastoreo extensivo, con medidas que apuestan por su protección y recuperación. En el presente texto se analiza el reconocimiento público del pastoreo en la Comunitat Valenciana, región admirativa que durante más de tres décadas ha reivindicado, en apariencia, la importancia de la ganadería extensiva en su acción política. Sin embargo, ante las limitaciones institucionales y burocráticas, en los últimos años emergen iniciativas que promueven enfoques nuevos y desconocidos en torno a la actividad pastoril, recuperando el anclaje territorial de los sistemas extensivos y tradicionales.
The loss of megafauna at the terminal Pleistocene has been linked to a wide range of Earth-system-level changes, such as altered greenhouse gas budgets, fire regimes and biome-level vegetation changes. Given these influences and feedbacks, might part of the solution for mitigating anthropogenic climate change lie in the restoration of extant megafauna to ecosystems? Here, we explore the potential role of trophic rewilding on Earth's climate system. We first provide a novel synthesis of the various ways that megafauna interact with the major drivers of anthropogenic climate change, including greenhouse gas storage and emission, aerosols and albedo. We then explore the role of rewilding as a mitigation tool at two scales: (i) current and near-future opportunities for national or regional climate change mitigation portfolios, and (ii) more radical opportunities at the global scale. Finally, we identify major knowledge gaps that complicate the complete characterization of rewilding as a climate change mitigation strategy. Our perspective is urgent since we are losing the Earth's last remaining megafauna, and with it a potential option to address climate change.
This article is part of the theme issue ‘Trophic rewilding: consequences for ecosystems under global change’.
How we manage farming and food systems to meet rising demand is pivotal to the future of biodiversity. Extensive field data suggest that impacts on wild populations would be greatly reduced through boosting yields on existing farmland so as to spare remaining natural habitats. High-yield farming raises other concerns because expressed per unit area it can generate high levels of externalities such as greenhouse gas emissions and nutrient losses. However, such metrics underestimate the overall impacts of lower-yield systems. Here we develop a framework that instead compares externality and land costs per unit production. We apply this framework to diverse data sets that describe the externalities of four major farm sectors and reveal that, rather than involving trade-offs, the externality and land costs of alternative production systems can covary positively: per unit production, land-efficient systems often produce lower externalities. For greenhouse gas emissions, these associations become more strongly positive once forgone sequestration is included. Our conclusions are limited: remarkably few studies report externalities alongside yields; many important externalities and farming systems are inadequately measured; and realizing the environmental benefits of high-yield systems typically requires additional measures to limit farmland expansion. Nevertheless, our results suggest that trade-offs among key cost metrics are not as ubiquitous as sometimes perceived. © 2018, The Author(s), under exclusive licence to Springer Nature Limited.
The global impacts of food production
Food is produced and processed by millions of farmers and intermediaries globally, with substantial associated environmental costs. Given the heterogeneity of producers, what is the best way to reduce food's environmental impacts? Poore and Nemecek consolidated data on the multiple environmental impacts of ∼38,000 farms producing 40 different agricultural goods around the world in a meta-analysis comparing various types of food production systems. The environmental cost of producing the same goods can be highly variable. However, this heterogeneity creates opportunities to target the small numbers of producers that have the most impact.
Science , this issue p. 987
In spite of negative perceptions, mobile pastoralism is a highly sustainable production system with clear environmental, social and economic benefits. This document makes the case for mobile pastoralism – a beneficial practice that is seriously threatened today, not just in the Mediterranean, but all over the world - through the revision of more than 100 scientific references.
How good or bad are livestock for the environment? Are domestic animals part of the problem or part of the solution when fighting, for example, climate change? There is not an easy (or correct) answer to these questions; it can be both, it very much depends on the way animals are reared, on the type of production systems. In other words, the key lies not so much with the animals themselves or their use as food, but with the ways animals are incorporated in agroecosystems and food systems (Gliessman, 2015).
This chapter attempts to shed some light on the controversial issue of grazing livestock and the environment, and to identify sustainable pathways of development that help to reconcile animal production, environmental preservation, and socio-cultural values that are important for society. The chapter is structured as follows. First, I shall discuss the wide diversity of livestock farming systems and their multiple (economic, socio-cultural, environmental) outcomes, briefly describe some contrasting trends in their recent evolution, and introduce the concepts of multifunctionality and ecosystem services (ES) and disservices (EDS). The ES framework will be used to describe the main negative and positive outcomes and livestock grazing systems (sections 3 and 4, respectively), and the multiple conflicts (trade-offs) that can arise between them. Next, I shall illustrate with a case study how we can value public (nonmarket) goods provided by grazing agroecosystems, with special emphasis on socio-cultural and economic perspectives (section 5). Finally, I shall introduce some strategies to design more sustainable grazing livestock systems using the principles of agroecology, and point to some guidelines for policy design (section 6).
In dryland Africa, access to land and water resources are central to pastoral livelihood activities. Policy intervention in these regions represents the outcome of concerted post-independence processes in which countries have committed to land tenure transformation as a policy objective. This was meant to create private, liberal property rights to replace communal customary tenure systems which were considered to be a constraint to development. Despite these efforts, decades of scientific research indicate that countries are still struggling to meet environmental sustainability objectives. Land degradation where it existed has not been halted and traditional pastoral livelihoods have been disrupted. The overall evidence base for policymaking remains weak as deficiencies in data or information on which management decisions were based led to poor policy performance. In a bid to strengthen understanding in this area, this study has a dual aim: 1. Using a systematic review of the literature, we examine the impact of land tenure transformation in pastoral areas in sub-Saharan Africa; 2. We analyse user-perspectives on land tenure transformation and pastoralists’ rights in Ngamiland, Botswana, so as to draw out the salient issues that must be addressed in order to reconcile pastoral tenure conflicts and land management in sub-Saharan Africa. Results from meta-analysis and case study show that land tenure transformation policies across pastoral areas are subject to similar challenges and consequences. Protecting pastoral land rights requires deliberate policy interventions that recognise pastoralism as a productive and efficient use of resources. Policymakers need to overcome anti-pastoral prejudice and focus on Sustainable Land Management goals. This entails establishing negotiated and flexible tenure frameworks that strengthen pastoralists’ participation in decision-making arenas by working with pastoral communities on the basis of understanding their livelihood system.
The extirpation of native wildlife species and widespread establishment of livestock farming has dramatically distorted large mammal herbivore communities across the globe. Ecological theory suggests that these shifts in the form and the intensity of herbivory have had substantial impacts on a range of ecosystem processes, but for most ecosystems it is impossible to quantify these changes accurately. We address these challenges using species-level biomass data from sub-Saharan Africa for both present day and reconstructed historical herbivore communities. Our analyses reveal pronounced herbivore biomass losses in wetter areas and substantial biomass increases and functional type turnover in arid regions. Fire prevalence is likely to have been altered over vast areas where grazer biomass has transitioned to above or below the threshold at which grass fuel reduction can suppress fire. Overall, shifts in the functional composition of herbivore communities promote an expansion of woody cover. Total herbivore methane emissions have more than doubled, but lateral nutrient diffusion capacity is below 5% of past levels. The release of fundamental ecological constraints on herbivore communities in arid regions appears to pose greater threats to ecosystem function than do biomass losses in mesic regions, where fire remains the major consumer.
Organic agriculture is proposed as a promising approach to achieving sustainable food systems, but its feasibility is also contested. We use a food systems model that addresses agronomic characteristics of organic agriculture to analyze the role that organic agriculture could play in sustainable food systems. Here we show that a 100% conversion to organic agriculture needs more land than conventional agriculture but reduces N-surplus and pesticide use. However, in combination with reductions of food wastage and food-competing feed from arable land, with correspondingly reduced production and consumption of animal products, land use under organic agriculture remains below the reference scenario. Other indicators such as greenhouse gas emissions also improve, but adequate nitrogen supply is challenging. Besides focusing on production, sustainable food systems need to address waste, crop–grass–livestock interdependencies and human consumption. None of the corresponding strategies needs full implementation and their combined partial implementation delivers a more sustainable food future.
The report dissects claims made by different stakeholders in the
debate about so called ‘grass-fed’ beef, the greenhouse gases the animals emit, and
the possibility that, through their grazing actions, they can help remove carbon dioxide
from the atmosphere. It evaluates these claims and counterclaims against the best
available science, providing an authoritative and evidence-based answer to the
question: Is grass-fed beef good or bad for the climate?
Background:
Livestock play an important role in carbon cycling through consumption of biomass and emissions of methane. Recent research suggests that existing bottom-up inventories of livestock methane emissions in the US, such as those made using 2006 IPCC Tier 1 livestock emissions factors, are too low. This may be due to outdated information used to develop these emissions factors. In this study, we update information for cattle and swine by region, based on reported recent changes in animal body mass, feed quality and quantity, milk productivity, and management of animals and manure. We then use this updated information to calculate new livestock methane emissions factors for enteric fermentation in cattle, and for manure management in cattle and swine.
Results:
Using the new emissions factors, we estimate global livestock emissions of 119.1 ± 18.2 Tg methane in 2011; this quantity is 11% greater than that obtained using the IPCC 2006 emissions factors, encompassing an 8.4% increase in enteric fermentation methane, a 36.7% increase in manure management methane, and notable variability among regions and sources. For example, revised manure management methane emissions for 2011 in the US increased by 71.8%. For years through 2013, we present (a) annual livestock methane emissions, (b) complete annual livestock carbon budgets, including carbon dioxide emissions, and (c) spatial distributions of livestock methane and other carbon fluxes, downscaled to 0.05 × 0.05 degree resolution.
Conclusions:
Our revised bottom-up estimates of global livestock methane emissions are comparable to recently reported top-down global estimates for recent years, and account for a significant part of the increase in annual methane emissions since 2007. Our results suggest that livestock methane emissions, while not the dominant overall source of global methane emissions, may be a major contributor to the observed annual emissions increases over the 2000s to 2010s. Differences at regional and local scales may help distinguish livestock methane emissions from those of other sectors in future top-down studies. The revised estimates allow improved reconciliation of top-down and bottom-up estimates of methane emissions, will facilitate the development and evaluation of Earth system models, and provide consistent regional and global Tier 1 estimates for environmental assessments.
This article deals with the rights-based approach to development that in the last decade has informed discourse on pastoralism. It focuses on the organisations that have engaged in pastoral advocacy at the global level, considering the dynamic conceptions of development, human rights and policy that provide their cultural and operative background. It outlines the convergence of indigenous rights with the core challenges of pastoralism, and the emergence of the new concept of 'pastoralists' rights', eventually considered as a separate domain. It argues that the mobility paradigm of pastoral development may not by itself provide an adequate answer to the problems of pastoral communities, unless explicit consideration is made of the collective and procedural rights recognised under the international human rights framework.
Defining rangelands as anthromes enabled Ellis and Ramankutty (2008) to conclude that more than three-quarters of Earth's land is anthropogenic; without rangelands, this figure would have been less than half. They classified all lands grazed by domestic livestock as rangelands, provided that human population densities were low; similar areas without livestock were excluded and classified instead as 'wildlands'. This paper examines the empirical basis and conceptual assumptions of defining and categorizing rangelands in this fashion. Empirically, we conclude that a large proportion of rangelands, although used to varying degrees by domesticated livestock, are not altered significantly by this use, especially in arid, highly variable environments and in settings with long evolutionary histories of herbivory by wild animals. Even where changes have occurred, the dynamics and components of many rangelands remain structurally and functionally equivalent to those that preceded domestic livestock grazing or would be found in its absence. In much of Africa and Asia, grazing is so longstanding as to be inextricable from 'natural' or reference conditions for those sites. Thus, the extent of anthropogenic biomes is significantly overstated. Conceptually, rangelands reveal the dependence of the anthromes thesis on outdated assumptions of ecological climax and equilibrium. Coming to terms with rangelands-how they can be classified, understood, and managed sustainably-thus offers important lessons for understanding anthromes and the Anthropocene as a whole. At the root of these lessons, we argue, is not the question of human impacts on ecosystems but property relations among humans.
Open-burning of rice straw residues pollutes the air and contributes to global warming through emissions of greenhouse gases (GHGs). Although burning of straw residues emits large amounts of CO2 , this component of the smoke is not considered as net GHG emissions and only concludes the annual carbon cycle that has started with photosynthesis. Hence, we focused on emissions of CH4 and N2O from open-field burning against a baseline of straw incorporation. The experimental approach combined a newly designed combustion chamber for the collection of smoke followed by chemical analysis (Exp. A) as well as field observations of soil-borne emissions for different straw treatments (Exp. B). At constant straw moisture of 10%, the mass-scaled Emission Factors (EF m) were 4.51 g CH 4 and 0.069 g N2O per kg dry weight (kg-1 dw) of straw. In Exp. B, we conducted field trials over two seasons with the following straw management practices: SRt - straw retained including stubbles and incorporated, PSRm - partial straw removal only stubbles incorporated, CSRm - complete straw removal including removal of stubbles, and SB - straw burned followed by incorporation of ash and unburned residues. Soil-borne emissions were recorded with a closed chamber approach whereas straw burning was computed indirectly using the EF from Exp. A. As metrics for comparison, we have used the GWP contributions of CH 4 and N 2 O for the different straw management practices over two cropping seasons in the field. On an annual basis, SRt had the highest total GWP (8023 kg CO2eq ha-1). SB entailed a GWP of 4913 kg CO2eq ha-1 that was almost identical to the GWP of PSRm (4531 kg CO2eq ha-1). CSRm had the lowest GWP (3470 kg CO2eq ha-1) that was significantly lower than that of SRt. However, full GHG accounting of straw removed from the field will depend on the ensuing utilization of straw and the off-field emissions involved - which was outside of the boundaries of this study. The quantification of open field burning in this study can be instrumental for diverse purposes by providing data of an important component in emission inventories and carbon footprint analysis of rice.
Livestock contribute to food security by supplying essential macro- and micro-nutrients, providing manure and draught power, and generating income. But they also consume food edible by humans and graze on pastures that could be used for crop production. Livestock, especially ruminants, are often seen as poor converters of feed into food products. This paper analyses global livestock feed rations and feed conversion ratios, with specific insight on the diversity in production systems and feed materials. Results estimate that livestock consume 6 billion tonnes of feed (dry matter) annually – including one third of global cereal production – of which 86% is made of materials that are currently not eaten by humans. In addition, soybean cakes, which production can be considered as main driver or land-use, represent 4% of the global livestock feed intake. Producing 1 kg of boneless meat requires an average of 2.8 kg human-edible feed in ruminant systems and 3.2 kg in monogastric systems. While livestock is estimated to use 2.5 billion ha of land, modest improvements in feed use efficiency can reduce further expansion.
Natural methane (CH<sub>4</sub>) emissions from wet ecosystems are an important part of today's global CH<sub>4</sub> budget. Climate affects the exchange of CH<sub>4</sub> between ecosystems and the atmosphere by influencing CH<sub>4</sub> production, oxidation, and transport in the soil. The net CH<sub>4</sub> exchange depends on ecosystem hydrology, soil and vegetation characteristics. Here, the LPJ-WHyMe global dynamical vegetation model is used to simulate global net CH<sub>4</sub> emissions for different ecosystems: northern peatlands (45°–90° N), naturally inundated wetlands (60° S–45° N), rice agriculture and wet mineral soils. Mineral soils are a potential CH<sub>4</sub> sink, but can also be a source with the direction of the net exchange depending on soil moisture content. The geographical and seasonal distributions are evaluated against multi-dimensional atmospheric inversions for 2003–2005, using two independent four-dimensional variational assimilation systems. The atmospheric inversions are constrained by the atmospheric CH<sub>4</sub> observations of the SCIAMACHY satellite instrument and global surface networks. Compared to LPJ-WHyMe the inversions result in a~significant reduction in the emissions from northern peatlands and suggest that LPJ-WHyMe maximum annual emissions peak about one month late. The inversions do not put strong constraints on the division of sources between inundated wetlands and wet mineral soils in the tropics. Based on the inversion results we diagnose model parameters in LPJ-WHyMe and simulate the surface exchange of CH<sub>4</sub> over the period 1990–2008. Over the whole period we infer an increase of global ecosystem CH<sub>4</sub> emissions of +1.11 Tg CH<sub>4</sub> yr<sup>−1</sup>, not considering potential additional changes in wetland extent. The increase in simulated CH<sub>4</sub> emissions is attributed to enhanced soil respiration resulting from the observed rise in land temperature and in atmospheric carbon dioxide that were used as input. The long-term decline of the atmospheric CH<sub>4</sub> growth rate from 1990 to 2006 cannot be fully explained with the simulated ecosystem emissions. However, these emissions show an increasing trend of +3.62 Tg CH<sub>4</sub> yr<sup>−1</sup> over 2005–2008 which can partly explain the renewed increase in atmospheric CH<sub>4</sub> concentration during recent years.
The widespread replacement of wild ungulate herbivores by domestic livestock in African savannas is composed of two interrelated phenomena: (1) loss or reduction in numbers of individual wildlife species or guilds and (2) addition of livestock to the system. Each can have important implications for plant community dynamics. Yet very few studies have experimentally addressed the individual, combined, and potentially interactive effects of wild vs. domestic herbivore species on herbaceous plant communities within a single system. Additionally, there is little information about whether, and in which contexts, livestock might functionally replace native herbivore wildlife or, alternatively, have fundamentally different effects on plant species composition. The Kenya Long-term Exclosure Experiment, which has been running since 1995, is composed of six treatment combinations of mega-herbivores, mesoherbivore ungulate wildlife, and cattle. We sampled herbaceous vegetation 25 times between 1999 and 2013. We used partial redundancy analysis and linear mixed models to assess effects of herbivore treatments on overall plant community composition and key plant species. Plant communities in the six different herbivore treatments shifted directionally over time and diverged from each other substantially by 2013. Plant community composition was strongly related (R2 = 0.92) to residual plant biomass, a measure of herbivore utilization. Addition of any single herbivore type (cattle, wildlife, or mega-herbivores) caused a shift in plant community composition that was proportional to its removal of plant biomass. These results suggest that overall herbivory pressure, rather than herbivore type or complex interactions among different herbivore types, was the main driver of changes in plant community composition. Individual plant species, however, did respond most strongly to either wild ungulates or cattle. Although these results suggest considerable functional similarity between a suite of native wild herbivores (which included grazers, browsers, and mixed feeders) and cattle (mostly grazers) with respect to understory plant community composition, responses of individual plant species demonstrate that at the plant-population-level impacts of a single livestock species are not functionally identical to those of a diverse group of native herbivores.
Increasing efficiency in livestock production and reducing the share of animal products in human consumption are two strategies to curb the adverse environmental impacts of the livestock sector. Here, we explore the room for sustainable livestock production by modelling the impacts and constraints of a third strategy in which livestock feed components that compete with direct human food crop production are reduced. Thus, in the outmost scenario, animals are fed only from grassland and by-products from food production. We show that this strategy could provide sufficient food (equal amounts of human-digestible energy and a similar protein/calorie ratio as in the reference scenario for 2050) and reduce environmental impacts compared with the reference scenario (in the most extreme case of zero human-edible concentrate feed: greenhouse gas emissions -18%; arable land occupation -26%, N-surplus -46%; P-surplus -40%; non-renewable energy use -36%, pesticide use intensity -22%, freshwater use -21%, soil erosion potential -12%). These results occur despite the fact that environmental efficiency of livestock production is reduced compared with the reference scenario, which is the consequence of the grassland-based feed for ruminants and the less optimal feeding rations based on by-products for non-ruminants. This apparent contradiction results from considerable reductions of animal products in human diets (protein intake per capita from livestock products reduced by 71%). We show that such a strategy focusing on feed components which do not compete with direct human food consumption offers a viable complement to strategies focusing on increased efficiency in production or reduced shares of animal products in consumption.
Livestock [inclusive of ruminant species, namely cattle (Bos Taurus and Bos indicus), sheep (Ovis aries), goats (Capra hircus), and buffaloes (Bubalus bubalis), and non-ruminant species, namely pigs (Sus scrofa domesticus) and chickens (Gallus domesticus)] are both affected by climate change and contribute as much as 14.5 % of global anthropogenic greenhouse gas (GHG) emissions, most of which is from ruminant animals (Gerber et al. 2013). This study aims to estimate the marginal costs of reducing GHG emissions for a selection of practices in the ruminant livestock sector (inclusive of the major ruminant species—cattle, sheep, and goats) globally. It advances on previous assessments by calculating marginal costs rather than commonly reported average costs of abatement and can thus provide insights about abatement responses at different carbon prices. We selected the most promising abatement options based on their effectiveness and feasibility. Improved grazing management and legume sowing are the main practices assessed in grazing systems. The urea (CO(NH2)2) treatment of crop straws is the main practice applied in mixed crop–livestock systems, while the feeding of dietary lipids and nitrates are confined to more intensive production systems. These practices were estimated to reduce emissions by up to 379 metric megatons of carbon dioxide (CO2) equivalent emissions per year (MtCO2-eq yr−1). Two thirds of this reduction was estimated to be possible at a carbon price of 20 US dollars per metric ton of CO2 equivalent emissions ($20 tCO2-eq−1). This study also provides strategic guidance as to where abatement efforts could be most cost effectively targeted. For example, improved grazing management was particularly cost effective in Latin America and Sub-Saharan Africa, while legume sowing appeared to work best in Western Europe and Latin America.
Significance
Most large mammals are endangered or vulnerable across the globe. Although the loss of charismatic fauna is of great concern, their role in ecosystem function remains poorly characterized. Here, we quantify one potential effect of the decline of large herbivores: the reduction of the greenhouse gas methane released as a byproduct of plant digestion. We examine three time periods where large-scale losses of megaherbivores occurred—the African rinderpest epizootic of the 1890s, the massive Great Plains bison kill-off in the 1860s, and the terminal Pleistocene extinction of megafauna. We find detectable decreases in the global methane budget related to the extirpation of megaherbivores. Our findings underscore the importance of large mammals in regulating ecosystems and feedbacks on climate.
Climate change (CC) directly impacts the economy, ecosystems, water resources, weather events, health issues, desertification, sea level rise, and even political and social stability. The effects of CC affect different groups of societies differently. In Tanzania, the effects of CC have even acquired a gender dimension, whereby women are viewed as more vulnerable than men because of socioeconomic and historic barriers. CC is largely caused by anthropogenic activities, including those that increase the concentrations of greenhouse gases (GHGs) in the atmosphere. Recent findings indicate that the livestock sector is responsible for 18 % of GHG emissions measured in the CO2 equivalent. Moreover, some gases emitted by livestock have higher potential to warm the atmosphere than CO2 and have a very long atmospheric lifetime. Methane (CH4) has 23 times the global warming potential (GWP) of CO2, whereas nitrous oxide (N2O) has 296 times the GWP of CO2. It is now estimated that the atmospheric concentrations of CH4 and N2O are increasing at a rate of approximately 0.6 % and 0.25 % per year, respectively. Cattle may emit CH4 from enteric fermentation equivalent to 2–12 % of the ingested energy, whereas produced manure can emit N2O up to 1.25 % of its weight. The estimated total CH4 and N2O emissions from Tanzanian ruminants stand at 26.17 Gg and 0.57 Gg, respectively. In this paper, we first very briefly review emissions of GHGs from different livestock production systems in Tanzania with the view of identifying the main hot spots. Then, we concentrate on the available adaptation options and the limitations on the adoption of such adaptation options in Tanzania. Emission of these GHGs per unit product varies with the level of intensification, the types of livestock kept, and manure management. Intensification of livestock production reduces the size of the land required to sustain a livestock unit and frees up the land necessary for carbon sequestration. In Tanzania, such intensification could take the form of the early harvesting and storing forage for dry-season feeding. The advantage of this intervention is twofold: young harvests have higher digestibility and emit less CH4 when fed to ruminants than mature lignified forage; use of stored roughage in the dry season will reduce the desertification of rangeland and deforestation that occur when livestock search for pastureland. Dry-season supplementation of ruminants with energy and protein-rich diets will reduce CH4 emission. The chemical treatment of crops byproducts will increase the crops’ digestibility and reduce CH4 emission from ruminants. Crossbreds of indigenous and exotic breeds are more efficient converters of feed into products like meat and milk, with less GHG emitted per unit product. The use of manure for biogas production will reduce the emission of both CH4 and N2O into the atmosphere. Shifting from liquid to solid manure management has the potential to reduce CH4 emissions. Most of these interventions, however, are not cost neutral – enhancing awareness alone will not lead to their widespread adoption. In the absence of subsidies, the adoption of these interventions will depend on the relative cost of other options. Although some traditional livestock systems in Tanzania are already coping with the impact of CC, such efforts are handicapped by inadequate resources, poor coordination, and implementation of competing measures.
Trophic rewilding is an ecological restoration strategy that uses species introductions to restore top-down trophic interactions and associated trophic cascades to promote self-regulating biodiverse ecosystems. Given the importance of large animals in trophic cascades and their widespread losses and resulting trophic downgrading, it often focuses on restoring functional megafaunas. Trophic rewilding is increasingly being implemented for conservation, but remains controversial. Here, we provide a synthesis of its current scientific basis, highlighting trophic cascades as the key conceptual framework, discussing the main lessons learned from ongoing rewilding projects, systematically reviewing the current literature, and highlighting unintentional rewilding and spontaneous wildlife comebacks as underused sources of information. Together, these lines of evidence show that trophic cascades may be restored via species reintroductions and ecological replacements. It is clear, however, that megafauna effects may be affected by poorly understood trophic complexity effects and interactions with landscape settings, human activities, and other factors. Unfortunately, empirical research on trophic rewilding is still rare, fragmented, and geographically biased, with the literature dominated by essays and opinion pieces. We highlight the need for applied programs to include hypothesis testing and science-based monitoring, and outline priorities for future research, notably assessing the role of trophic complexity, interplay with landscape settings, land use, and climate change, as well as developing the global scope for rewilding and tools to optimize benefits and reduce human–wildlife conflicts. Finally, we recommend developing a decision framework for species selection, building on functional and phylogenetic information and with attention to the potential contribution from synthetic biology.
An analysis of the climate impact of various forms of beef production is carried out, with a particular eye to the comparison between systems relying primarily on grasses grown in pasture ('grass-fed' or 'pastured' beef) and systems involving substantial use of manufactured feed requiring significant external inputs in the form of synthetic fertilizer and mechanized agriculture ('feedlot' beef). The climate impact is evaluated without employing metrics such as CO e 2 or global warming potentials. The analysis evaluates the impact at all time scales out to 1000 years. It is concluded that certain forms of pastured beef production have substantially lower climate impact than feedlot systems. However, pastured systems that require significant synthetic fertilization, inputs from supplemental feed, or deforestation to create pasture, have substantially greater climate impact at all time scales than the feedlot and dairy-associated systems analyzed. Even the best pastured system analyzed has enough climate impact to justify efforts to limit future growth of beef production, which in any event would be necessary if climate and other ecological concerns were met by a transition to primarily pasture-based systems. Alternate mitigation options are discussed, but barring unforseen technological breakthroughs worldwide consumption at current North American per capita rates appears incompatible with a 2 °C warming target.
Wood-pastures are archetypes of High Nature Value Farmlands in Europe and hold exceptional ecological, social, and cultural values. Yet, wood-pastures have been through a sharp decline all over Europe, mainly due to processes of agricultural intensification and abandonment. Recently, wood-pastures have found increasing attention from conservation science and policy across Europe. In this paper we (i) perform the first pan-European assessment of wood-pastures, considering individual countries and biogeographic regions, (ii) present the ecological and social–cultural values of a wide diversity of wood-pasture systems in Europe, (iii) outline management challenges around wood-pastures, and (iv) provide insights for the policy agenda targeting wood-pastures in Europe. We estimate that wood-pastures cover an area of approximately 203,000 km2 in the European Union (EU). They are distributed across all biogeographical regions, but more abundantly in the Mediterranean and Eastern European countries. Substantial ecological values are revealed in terms of landscape level biodiversity, ecosystem dynamics, and genetic resources. Social–cultural values are related to aesthetic values, cultural heritage, and rich traditional ecological knowledge. We discuss the anthropogenic character of wood-pastures, requiring multifunctional land management, which is a major conservation challenge. Despite increasing societal appreciation of wood-pastures, their integration into effective agricultural and conservation policies has proved to be complicated, because institutional structures are traditionally organized within mono-functional sectors. We offer suggestions as to how these shortcomings might be overcome in the Common Agricultural Policy, including Rural Development policy, and the Habitats Directive of the EU. We conclude that research should be guided by a holistic vision of wood-pastures, which integrates information about ecology, societal values, and institutional arrangements.
Methane is an important greenhouse gas but characterizing production by source sector has proven difficult. Current estimates suggest herbivores produce ~20% (~76-189 Tg yr(-1) ) of methane globally, with wildlife contributions uncertain. We develop a simple and accurate method to estimate methane emissions and reevaluate production by wildlife. We find a strikingly robust relationship between body mass and methane output exceeding the scaling expected by differences in metabolic rate. Our allometric model gives a significantly better fit to empirical data than IPCC Tier 1 and 2 calculations. Our analysis suggests that: a) the allometric model provides an easier and more robust estimate of methane production than IPCC models currently in use, b) output from wildlife is much higher than previously considered, and c) because of the sublinear allometric scaling of methane output with body mass, national emissions could be reduced if countries favored more, smaller livestock, over fewer, larger ones. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.
The ‘sustainable intensification’ (SI) approach and ‘climate-smart agriculture’ (CSA) are highly complementary. SI is an essential means of adapting to climate change, also resulting in lower emissions per unit of output. With its emphasis on improving risk management, information flows and local institutions to support adaptive capacity, CSA provides the foundations for incentivizing and enabling intensification. But adaptation requires going beyond a narrow intensification lens to include diversified farming systems, local adaptation planning, building responsive governance systems, enhancing leadership skills, and building asset diversity. While SI and CSA are crucial for global food and nutritional security, they are only part of a multi-pronged approach, that includes reducing consumption and waste, building social safety nets, facilitating trade, and enhancing diets.
Modern wetlands are the world's strongest methane source. But what was the role of this source in the past? An analysis of global 14C data for basal peat combined with modelling of wetland succession allowed us to reconstruct the dynamics of global wetland methane emission through time. These data show that the rise of atmospheric methane concentrations during the Pleistocene-Holocene transition was not connected with wetland expansion, but rather started substantially later, only 9 thousand years ago. Additionally, wetland expansion took place against the background of a decline in atmospheric methane concentration. The isotopic composition of methane varies according to source. Owing to ice sheet drilling programs past dynamics of atmospheric methane isotopic composition is now known. For example over the course of Pleistocene-Holocene transition atmospheric methane became depleted in the deuterium isotope, which indicated that the rise in methane concentrations was not connected with activation of the deuterium-rich gas clathrates. Modelling of the budget of the atmospheric methane and its isotopic composition allowed us to reconstruct the dynamics of all main methane sources. For the late Pleistocene, the largest methane source was megaherbivores, whose total biomass is estimated to have exceeded that of present-day humans and domestic animals. This corresponds with our independent estimates of herbivore density on the pastures of the late Pleistocene based on herbivore skeleton density in the permafrost. During deglaciation, the largest methane emissions originated from degrading frozen soils of the mammoth steppe biome. Methane from this source is unique, as it is depleted of all isotopes. We estimated that over the entire course of deglaciation (15,000 to 6,000 year before present), soils of the mammoth steppe released 300-550 Pg (1015 g) of methane. From current study we conclude that the Late Quaternary Extinction significantly affected the global methane cycle.
Significance
The livestock sector contributes significantly to global warming through greenhouse gas (GHG) emissions. At the same time, livestock is an invaluable source of nutrition and livelihood for millions of poor people. Therefore, climate mitigation policies involving livestock must be designed with extreme care. Here we demonstrate the large mitigation potential inherent in the heterogeneity of livestock production systems. We find that even within existing systems, autonomous transitions from extensive to more productive systems would decrease GHG emissions and improve food availability. Most effective climate policies involving livestock would be those targeting emissions from land-use change. To minimize the economic and social cost, policies should target emissions at their source—on the supply side—rather than on the demand side.
Fodder trees are important feed sources fo