Christian Lauk

• Doctor of Philosophy
• Senior Researcher at BOKU University

As a major source of greenhouse gas (GHG) emissions and with a substantial potential of carbon storage, agriculture and food (agri-food) systems play a twofold role in achieving the Paris goal of well below 2 • C of global warming. Against this background, this paper assesses the mitigation potentials, economic effects, co-benefits and trade-offs o...

Societal activities massively alter the global carbon (C) cycle, thereby driving global climate heating. Socioeconomic material stocks – e.g., in buildings and infrastructures – have been identified as a C pool that can potentially store increasing amounts of C, thereby keeping C away from the atmosphere. However, little is known about the size, co...

Emissions from agricultural activities constitute 11% of global greenhouse gas emissions and are hard to abate. Here, we present and analyze a consistent empirical assessment of global emissions from agricultural activities from 1910-2015. Agricultural emissions increased 3.5-fold from 1910-2015, from 1.9 to 6.7 GtCO2eq/yr. CH4 emissions, emissions...

Wildfires and land use play a central role in the long‐term carbon (C) dynamics of forested ecosystems of the United States. Understanding their linkages with changes in biomass, resource use, and consumption in the context of climate change mitigation is crucial. We reconstruct a long‐term C balance of forests in the contiguous U.S. using historic...

Transforming the global food system is necessary to avoid exceeding planetary boundaries. A robust evidence base is crucial to assess the scale and combination of interventions required for a sustainable transformation. We developed a risk assessment framework, underpinned by a meta-regression of 60 global food system modeling studies, to quantify...

Urbanization processes are accompanied by growing global challenges for food systems. Urban actors are increasingly striving to address these challenges through a focus on sustainable diets. However, transforming food systems towards more sustainable diets is challenging and it is unclear what the local scope of action might be. Co-production of kn...

Land use faces a double challenge: to provide biomass to a growing population while contributing to climate-change mitigation. We here scrutinize this challenge by exploring the domestic option space for meeting the food demand of Austria in 2050 under the condition of no deforestation. To that end, we bring together a quantitative assessment based...

Wood products function as carbon storage even after being harvested from forests. This has garnered attention in relevance to climate change countermeasures. In the progress of efforts toward climate change mitigation by private companies, the effective use of wood products has been an important measure. However, the methodology for accounting carb...

Short food supply chains and circularity are discussed as key factors for a sustainable food system. Although self-sufficiency ratios (SSR) are often used to characterize agri-food systems, the concept of SSR remains inconsistently defined, particularly when means of production such as livestock feed are explicitly considered. We present a systemat...

The provision of food is fundamental for society, but it is also a major driver of environmental change. Cities are important consumers of food, harboring more than half of the global population, a share that is expected to grow in the coming decades. Here we investigate the urban food system of Vienna, a large central European city. We quantify th...

Close to 40% of Earth's land area is used for agriculture to provide humankind with plant- and animal-based food, fibers or bioenergy. Future trends in agricultural land use, livestock husbandry and associated environmental pressures are determined by developments in the food sector, agricultural productivity, technology, and many other influencing...

Material stocks in infrastructure, buildings and machinery shape current and future resource use and emissions. Analyses of specific countries and selected materials suggest that material stocks might saturate, which would be important for a more sustainable social metabolism. However, it is unclear to what extent the evidence holds for a wider ran...

Their geomorphological characteristics make island systems special focal points for sustainability challenges. The Circular Economy (CE) Action Plan of the European Union foresees tailored solution sets for Europe's outermost regions and islands to tackle region‐specific sustainability challenges. We address the question of how islands can achieve...

Achieving a global forest transition, that is a shift from deforestation to reforestation, is important for climate-change mitigation. Forest transitions are enabled by socioecological processes, including land displacement, agricultural intensification and woodfuel substitution for other energy, but their respective contributions remain poorly und...

Sustainable food systems face trade-offs between demands of low environmental pressures per unit area and requirements of increasing production. Organic farming has lower yields than conventional agriculture and requires the introduction of nitrogen (N) fixing legumes in crop rotations. Here we perform an integrated assessment of the feasibility of...

The dataset includes 90 global food system and land use scenarios developed with the model BioBaM-GHG 2.0. The scenarios have been developed for assessing the global potential of forest regeneration for climate mitigation to 2050 under various food system pathways, i.e. diets, crop yield developments, land requirements for energy crops, and two var...

This is a comprehensive dataset of the agriculture and food system scenarios co-developed with stakeholders with the agricultural land use model BioBaM-GHG 2.0 and presented in Deliverable 4.2 of the H2020 project UNISECO. It includes sub-national (NUTS1/2-level) data on agricultural production and consumption, land use, greenhouse gas emissions fr...

The circular economy is a rapidly emerging concept promoted as transformative approach towards sustainable resource use within Planetary Boundaries. It is gaining traction with policymakers, industry and academia worldwide. It promises to slow, narrow and close socioeconomic material cycles by retaining value as long as possible, thereby minimizing...

The world population is expected to rise to 9.7 billion by 2050 and to ~11 billion by 2100, and securing its healthy nutrition is a key concern. As global fertile land is limited, the question arises whether growth in food consumption associated with increased affluence surmounts increases in land-use efficiency (measured as food supply per croplan...

This is a 40 seconds long teaser video showing sankey diagrams of the global metabolism including circular flows for 115 years in 5 year steps.

This is the uncertainty assessment for the article "Spaceship earth’s odyssey to a circular economy: A century long perspective" in Resources, Conservation & Recycling, 2020

These are the data for the article "Spaceship earth’s odyssey to a circular economy: A century long perspective" in Resources, Conservation & Recycling, 2020. It covers DE for the main material categories (fossil materials, biomass, metals, non-metallic minerals), the circular and non-circular flows and the data for the uncertainty analysis.

Video on the content of the article "Spaceship earth's odyssey to a circular economy - a century long perspective" showing with Sankey-diagrams how global material and energy flows increase since 1900

Global food systems contribute to climate change, the transgression of planetary boundaries and deforestation. An improved understanding of the environmental impacts of different food system futures is crucial for forging strategies to sustainably nourish a growing world population. We here quantify the greenhouse gas (GHG) emissions of global food...

Global bioenergy potentials have been the subject of extensive research and continued controversy. Due to vast uncertainties regarding future yields, diets and other influencing parameters, estimates of future agricultural biomass potentials vary widely. Most scenarios compatible with ambitious climate targets foresee a large expansion of bioenergy...

Sedentary extensive small ruminant farming systems are highly important for the preservation of High Nature Value (HNV) farmland. Both the abandonment of grazing and overgrazing have led to environmental degradation in many Mediterranean regions. On the Greek island of Samothrace, decades of overgrazing by sheep and goats has caused severe degradat...

Short rotation plantations are often considered as holding vast potentials for future global bioenergy supply. In contrast to raising biomass harvests in forests, purpose-grown biomass does not interfere with forest carbon (C) stocks. Provided that agricultural land can be diverted from food and feed production without impairing food security, ener...

Achieving a global forest transition, that is, a shift from net deforestation to reforestation, is essential for climate change mitigation. However, both land-based climate change mitigation policy and research on forest transitions neglect key processes that relieve pressure from forests, but cause emissions elsewhere (‘hidden emissions’). Here, w...

We compare the C sink strength of natural succession on arable land with the C mitigation effects of plantation-based bioenergy. Using geographically explicit data on global cropland distribution among climate and ecological zones, regionally specific C accumulation rates are calculated using IPCC default methods and values. C savings from bioenerg...

Second generation biofuels (2G biofuels) produced from lignocellulosic biomass are often considered as integral part of a future sustainable transport system. Provided that substantial areas of agricultural land can be diverted from food and feed production without impairing food security, energy plantations managed in short rotation appear as a pr...

Assessing progress towards environmental sustainability requires a robust and systematic knowledge base. Economy-wide material flow accounting (ew-MFA) is an established method to monitor resource use across scales and its headline indicators are widely used in policy. However, ew-MFA is currently limited by its empirical focus on annual flows of m...

The size and structure of the socioeconomic metabolism are key for the planet’s sustainability. In this article, we provide a consistent assessment of the development of material flows through the global economy in the period 1900–2015 using material flow accounting in combination with results from dynamic stock-flow modelling. Based on this approa...

Carbon stocks in vegetation have a key role in the climate system. However, the magnitude, patterns and uncertainties of carbon stocks and the effect of land use on the stocks remain poorly quantified. Here we show, using state-of-the-art datasets, that vegetation currently stores around 450 petagrams of carbon. In the hypothetical absence of land...

Hypothetic absorption potentials of carbon stock restorations and indicative years until saturation at a current emission level of 9 PgC yr-1. Note that a restoration to 100% of the potential probably entails a cessation of the respective land use, due to the intrinsic relations of harvest and carbon stocks25. *Years until saturation at current C-e...

Comparison of the difference between potential and actual biomass stocks to components of the global carbon balance, including LUC emissions and net terrestrial biosphere sink. Bold figures refer to results of this study, all others represent independent estimates. The difference in biomass stock of 447 PgC (375-525) is well in line with estimates...

Given the intricate link between biodiversity and poverty, this paper critically reflects on the role of mainstreaming biodiversity in development policy and practice. In order to better understand the operational challenges ‘on the ground’, we present some of the dominant development frameworks within which development organizations operate, all w...

To date the concept of the bioeconomy—an economy based primarily on biogenic instead of fossil resources—has largely been associated with visions of " green growth " and the advancement of biotechnology and has been framed from within an industrial perspective. However, there is no consensus as to what a bioeconomy should effectively look like, and...

Data S1. Bioenergy production and sustainable development: limited science base for policy making‐Protocol. Table S1. Characterization. Table S2. Conditions. Table S3. Potential impacts. Table S4. Possible answers to potential impacts.

Data S3. Article selection and data extraction. Table S13. Basic set of articles. Table S14. Appraisal results. Table S15. Set of studies included in the data extraction. Table S16. Data extraction – Characterization. Table S17. Data extraction – Conditions. Table S18. Data extraction – Potential impacts.

Data S2. Additional results. Table S5. Number of studies per category and impact (n = 316). Table S6. Positive, negative and neutral impacts. Table S7. Methodological approaches used. Table S8. Methodological approach per impact considered. Table S9. Number of articles per method. Table S10. Cross‐analysis potential vs. bioenergy resource. T...

Data S4. Regional distribution of each impact considered in the systematic review. Figure S1. Regional distribution of impacts on energy independence. Figure S2. Regional distribution of impacts on land tenure. Figure S3. Regional distribution of impacts on cross‐sectoral coordination. Figure S4. Regional distribution of impacts on labour right...

Significance A large part of all primary materials extracted globally accumulates in stocks of manufactured capital, including in buildings, infrastructure, machinery, and equipment. These in-use stocks of materials provide important services for society and the economy and drive long-term demand for materials and energy. Configuration and quantity...

The transformation towards a low-carbon bioeconomy until 2050 is one of the main strategic long-term targets of the European Union. This work presents transformation scenarios for the case of Austria with GHG reduction to about 20% of Kyoto baseline. The scenarios are developed with an optimization model integrating the energy sector, land use and...

There is evidence that the replacement of carbon-intensive products with bio-based substitutes (‘material substitution with biomass’) can be highly efficient in reducing greenhouse gas (GHG) emissions. Based on two case studies (CS1/2) for Austria, potential benefits of material substitution in comparison to fuel substitution are analysed. GHG savi...

The terrestrial carbon cycle is not well quantified. Biomass turnover time is a crucial parameter in the global carbon cycle and contributes to the feedback between the terrestrial carbon cycle and climate. Biomass turnover time varies substantially in time and space, but its determinants are not well known making predictions of future global carbo...

This chapter introduces competition as a heuristic concept to analyse how specific land use practices establish themselves against possible alternatives. We briefly outline the global importance of land use practices as the material and symbolic basis for people’s livelihoods, particularly the provision of food security and well-being. We chart the...

In land system science, the issue of land use competition is often explored in the context of future scenarios of the agro-food system. While land system science shares its research topic with the so-called agro-food studies, there is little communication between these two strands of research. In order to explore the reasons for this communicative...

Despite their central role in land-use transitions, changes in land-use intensity are only poorly understood, and databases for systematically analyzing change in land-use intensity are largely missing. This knowledge gap is critical because, due to the anticipated changes in global population numbers and food, fiber and energy demand, the developm...

Global surges in biomass demand driven by an increasing world population, nutrition transitions in the developing world and increasing consumption of bioenergy are pressuring African land-use systems and threatening the sustainability of yet-intact ecosystems. Africa is not exempt from this land rush. In fact, much hope is placed in African lands f...

The concept of forest transitions was introduced by geographers in the 1990s to describe the observation that forests regrow with industrialization in many parts of the world. We use the case of Austria to discuss the forest transition in the context of Social Ecology based on empirical evidence on Austria’s carbon budget in the period 1830–2010. I...

Livestock production plays a key role in national and regional economies, for food security and poverty alleviation, the climate system, biodiversity, and the biogeochemical cycles of carbon, nitrogen and water. In the near future, the importance of livestock is bound to increase due to anticipated economic developments and associated changes in hu...

Human-induced vegetation fires play a central role in past and present nature-society interactions. Tens of thousands of years ago, hunter-gatherers presumably employed fires as a hunting technique. Today, vegetation fires continue to be an integral part of shifting cultivation and traditional pastoralism, and they are a crucial tool for the cleari...

Land is a key resource, not only for human societies but also for all organisms—animals, plants and microorganisms—that inhabit terrestrial ecosystems worldwide. Humans use land for at least three purposes: resource supply, waste repository and living space (i.e., the area required for production, consumption, transport, recreation and many other a...

Safeguarding the world's remaining forests is a high-priority goal. We assess the biophysical option space for feeding the world in 2050 in a hypothetical zero-deforestation world. We systematically combine realistic assumptions on future yields, agricultural areas, livestock feed and human diets. For each scenario, we determine whether the supply...

Supplementary Figures 1-7, Supplementary Tables 1-9, Supplementary Methods and Supplementary References

The possibility of using bioenergy as a climate change mitigation measure has sparked a discussion of whether and how bioenergy production contributes to sustainable development. We undertook a systematic review of the scientific literature to illuminate this relationship and found a limited scientific basis for policy-making. Our results indicate...

Dieser Beitrag lotet die spezifischen politischen Fragestellungen aus, die eine Begrenzung der Verfügbarkeit von Metallen aufwirft. Damit soll eine erste Einschätzung der globalen Verteilungs‐ und Wachstumsfrage gegeben werden, die in der Diskussion um strategische Metalle impliziert ist. Insbesondere wird die Bereitstellung von Metallen aus periph...

http://link.springer.com/book/10.1007%2F978-3-319-33628-2

This chapter introduces competition as a heuristic concept to analyse how specific land use practices establish themselves against possible alternatives. We briefly outline the global importance of land use practices as the material and symbolic basis for people’s livelihoods, particularly the provision of food security and well-being. We chart the...

Understanding patterns, dynamics, and drivers of land use is crucial for improving our ability to cope with sustainability challenges. The human appropriation of net primary production (HANPP) framework provides a set of integrated socio-ecological indicators that quantify how land use alters energy flows in ecosystems via land conversions and biom...

The economic and societal challenges related to a significant reduction in greenhouse gas (GHG) emissions and establishing a bioeconomy are considerable, and it is necessary to gain a clear view of how a transformation can be accomplished. There is currently little knowledge on the feasibility and implications of such a transformation on a national...

In recent years, the strategic role certain metals play is seen as central to the geopolitics promulgated by state agents in the North. While a switch to renewable energy and an increase in energy efficiency might be instrumental to reducing dependence on fossil energy, it increases dependence on metals. This paper starts from an analysis of the li...

Global increases in population, consumption, and gross domestic product raise concerns about the sustainability of the current and future use of natural resources. The human appropriation of net primary production (HANPP) provides a useful measure of human intervention into the biosphere. The productive capacity of land is appropriated by harvestin...

Feeding nine to ten billion people by 2050 and preventing dangerous climate change are two of the greatest challenges facing humanity. Both challenges must be met whilst reducing the impact of land management on ecosystem services that deliver vital goods and services, and support human health and well-being. Few studies to date have considered the...

Human land use has major impacts on natural ecosystems. The human appropriation of net primary production (HANPP) is a prominent socio-ecological indicator of land use intensity. HANPP measures two different processes: (1) changes in productivity of natural ecosystems induced by humans, and (2) the amount of biomass harvested or destroyed during ha...

A better understanding of the global carbon cycle as well as of climate change mitigation options such as carbon sequestration requires the quantification of natural and socioeconomic stocks and flows of carbon. A so-far under-researched aspect of the global carbon budget is the accumulation of carbon in long-lived products such as buildings and fu...

The current economy is growth-addicted because it is geared towards profits. Profit making is driven by status competition. For an economy to degrow, social innovations are required that replace markets with cooperation and foster social equality. An economy that is able to degrow can also enter a steady state of constant production and consumption...

Biofuels are currently in the middle of a heated academic and public policy debate. Biofuel production has increased fivefold in the past decade and is expected to further double by 2020. Most of this expansion will happen in developing nations. This volume is the first of its kind, providing a comprehensive overview of the biofuel debate in develo...