Stephen Polasky’s research while affiliated with St. Catherine University and other places

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Publications (491)


How to make land use policy decisions: Integrating science and economics to deliver connected climate, biodiversity, and food objectives
  • Article

November 2024

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225 Reads

Proceedings of the National Academy of Sciences

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Ethan T. Addicott

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[...]

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Brett H. Day

Land use change is crucial to addressing the existential threats of climate change and biodiversity loss while enhancing food security [M. Zurek et al. , Science 376 , 1416–1421 (2022)]. The interconnected and spatially varying nature of the impacts of land use change means that these challenges must be addressed simultaneously [H.-O. Pörtner et al. , Science 380 , eabl4881 (2023)]. However, governments commonly focus on single issues, incentivizing land use change via “Flat-Rate” subsidies offering constant per hectare payments, uptake of which is determined by the economic circumstances of landowners rather than the integrated environmental outcomes that will be delivered [G. Q. Bull et al. , Forest Policy Econ. 9 , 13–31 (2006)]. Here, we compare Flat-Rate subsidies to two alternatives: “Land Use Scenario” allocation of subsidies through consultation across stakeholders and interested parties; and a “Natural Capital” approach which targets subsidies according to expected ecosystem service response. This comparison is achieved by developing a comprehensive decision support system, integrating new and existing natural, physical, and economic science models to quantify environmental, agricultural, and economic outcomes. Applying this system to the United Kingdom’s net zero commitment to increase carbon storage via afforestation, we show that the three approaches result in significantly different outcomes in terms of where planting occurs, their environmental consequences, and economic costs and benefits. The Flat-Rate approach actually increases net carbon emissions while Land Use Scenario allocation yields poor economic outcomes. The Natural Capital targeted approach outperforms both alternatives, providing the highest possible social values while satisfying net zero commitments.


Agriculture and conservation: living nature in a globalised world
  • Technical Report
  • Full-text available

October 2024

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236 Reads

"This report comprises two parts. Part I, the bulk of the report, assesses the relationships between nature conservation and agriculture in our globalised world, drawing from data, publications, and expertise from IUCN and beyond. Chapter 1 provides definitions and framing of ‘agriculture’, ‘nature’, and associated terms. Chapter 2 uses both synthesis of the evidence and empirical analysis to explore how agriculture affects nature. Chapter 3, conversely, explores the impacts that nature, mediated by ecosystem services and disservices, has on agriculture. Drawing from these, Chapter 4 harnesses integrated assessment modelling to examine the prospects for simultaneous achievement of global goals for both agriculture and conservation. Chapter 5 then examines a range of realistic policy scenarios currently under discussion in the agriculture and conservation sectors and beyond. Chapter 6 concludes with key messages emerging from the report. Finally, Part II documents four key indicators of nature and conservation, drawing in part from data based on IUCN standards for countries across the world."

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A cautious approach to subsidies for environmental sustainability

October 2024

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495 Reads

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1 Citation

Science

Tackling climate change and biodiversity loss will require government policies to reverse environmental destruction and align economic activity with sustainability goals. Subsidy-based policies feature prominently in current national and international policy discussions about ways to address these challenges. Given this, now is a critical moment to reassess the role of subsidies to ensure that not only their benefits but also their potential drawbacks are at the forefront of discussions about their use and design. We suggest that subsidies can play an important role in protecting people and the planet. However, because subsidies can have considerable drawbacks, we also suggest that subsidies should be used cautiously to ensure that they are, on net, beneficial to society and the planet in the short and long run. Avoiding “lock-in” is paramount and can be achieved through initial design features such as time limits to sunset subsidies.



Quantifying disturbance effects on ecosystem services in a changing climate

August 2024

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86 Reads

Disturbances, such as hurricanes, fires, droughts, and pest outbreaks, can cause major changes in ecosystem conditions that threaten nature’s contributions to people (ecosystem services). However, approaches to assess these impacts on diverse services under climate change are rare. To advance such efforts, we build on the accelerating research on disturbance ecology and ecosystem services to develop a functional trait-based approach to quantify ecological, ecosystem service, and economic outcomes under risk and climate change. We demonstrate this general approach by quantifying impacts to ecosystem services—timber and recreational enjoyment—from extreme windstorms in a mid-latitude forest. We find that expected ecosystem service losses from these windstorm disturbances are large and likely to increase with climate change. Yet, we show that common ecological metrics of compositional and biomass stability are inadequate for predicting these impacts to ecosystem service, necessitating more direct measures of services with disturbance. We then illustrate our approach for other applications spanning different ecosystems, services, and disturbances, including crop pollination, flood hazard mitigation, and cultural values. These examples highlight the pressing need to consider disturbances in future ecosystem service assessments, given the increase in mega-disturbances occurring globally with climate change.


Fig. 1 | Conceptual framework guiding our analysis. Institutional design processes can provide necessary steering capacities in the form of emergency response and large-scale coordination, curation of information, standards, and best practices. These public goods -steering capacities -provide, in turn, stability, raised awareness, and easy-to-follow behavioral guidelines, which in turn are important for addressing behavioral barriers to change, namely a failure to recognize the fragility of the Biosphere and the urgency of the problem, the diversity of value prioritization, and hesitancy to act. Raising awareness can also leverage and influence our proenvironmental and prosocial values and behaviors (altruism, empathy and capacity to cooperate), making them more aligned with necessary actions. However, unintended consequences (e.g., corruption) can emerge if institutional design does not account for human behavior. Image credit: Azote.
Titanic lessons for Spaceship Earth to account for human behavior in institutional design

July 2024

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211 Reads

npj Climate Action

Combating environmental degradation requires global cooperation. We here argue that institutional designs for such efforts need to account for human behavior. The voyage of the Titanic serves as an analogous case to learn from, and we use behavioral insights to identify critical aspects of human behavior that serve as barriers or opportunities for addressing the challenges we face. We identify a set of public goods that may help us mitigate identified negative aspects of human behavior, while leveraging the positive aspects: standards and best practices, mechanisms for large-scale coordination, and curation of information to raise awareness and promote action. We use existing international organizations, providing at least one of these capacities, as cases to learn from before applying our insights to existing institutional solutions for global environmental protection. We identify institutional design features that, if adapted to better account for human behavior, could lead to more effective institutional solutions.



Utilizing basic income to create a sustainable, poverty-free tomorrow

June 2024

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268 Reads

The coronavirus disease 2019 (COVID-19) pandemic of 2020 was a reminder of society’s vulnerability in the face of natural upheavals, leading to widespread unemployment and increased poverty. Simultaneously, human activities have precipitated large-scale environmental degradation and catastrophic climate change. Here, we conduct a global-scale, 186-country analysis examining the potential impact of basic income (BI) as a two-pronged solution to both sustainability and social resilience. We reveal BI’s potential to bolster economies, particularly in times of crisis. To lower the huge barrier imposed by implementation costs, we suggest a diverse array of strategies aimed at financing BI, strategically designed to concurrently alleviate economic insecurity while fostering nature conservation. We suggest that BI implementation is feasible and could be a potent tool in addressing the twin challenges of decreasing worldwide poverty while reducing environmental degradation—a nexus that arguably constitutes the paramount global challenge of our times.



Average relative yield gaps for ten major crops in 1975 and 2010
Crops include barley, cassava, maize, oil palm, rapeseed, rice, sorghum, soybean, sugar cane and rice. Relative yield gap (shown as the percentage of the attainable yield achieved) in each grid cell is calculated as an area-weighted average across the crops and is shown on the top 98% of the growing area.
Time to closure of yield gaps based on linear extrapolation of trends from circa 2000 to circa 2010 for maize, rice, wheat and soybean
Yield gap closure time is defined as the crossing point of the linear trend of attainable yield and the linear trend of actual yield relative to 2010. ‘No trend’ indicates that no yield gap closure occurs within 95th percentile confidence intervals. ‘Widen’ indicates that yield ceiling and linear trend are significantly diverging (that is, the crossing point is before 2010). See Supplementary Fig. 3 for other crops.
Typologies of yield gap closure
a, ‘Steady growth’ category, an archetype of which is the situation when attainable yield (‘ceiling’) and actual yield (‘floor’) benefit from agronomic investment in new technologies and increased uptake of management practices. b, ‘Stalled floor’ category; yield gap is increasing because ‘best in class’ management practices for maximizing yield are not widely adopted for reasons that could include economic barriers, selection of lower-yielding higher-quality cultivars or adoption of environmental policies. c, ‘Ceiling pressure’ category, in which small yield gaps indicate a need for breeding and ‘new agronomy’²⁴ to improve yield ceilings. Some archetypal examples are shown in Supplementary Fig. 5.
Maps of typologies of yield gap change for maize, rice, wheat and soybean
Typologies are as defined in the text and illustrated in Fig. 3. Maps for other crops are shown in Supplementary Fig. 4.
Global spatially explicit yield gap time trends reveal regions at risk of future crop yield stagnation

January 2024

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456 Reads

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31 Citations

Nature Food

Yield gaps, here defined as the difference between actual and attainable yields, provide a framework for assessing opportunities to increase agricultural productivity. Previous global assessments, centred on a single year, were unable to identify temporal variation. Here we provide a spatially and temporally comprehensive analysis of yield gaps for ten major crops from 1975 to 2010. Yield gaps have widened steadily over most areas for the eight annual crops and remained static for sugar cane and oil palm. We developed a three-category typology to differentiate regions of ‘steady growth’ in actual and attainable yields, ‘stalled floor’ where yield is stagnated and ‘ceiling pressure’ where yield gaps are closing. Over 60% of maize area is experiencing ‘steady growth’, in contrast to ∼12% for rice. Rice and wheat have 84% and 56% of area, respectively, experiencing ‘ceiling pressure’. We show that ‘ceiling pressure’ correlates with subsequent yield stagnation, signalling risks for multiple countries currently realizing gains from yield growth.


Citations (72)


... Today, the advent of artificial intelligence (AI) and extremely large datasets (e.g. remotely sensed data) offers an opportunity to advance the field and meet the needs of policy in producing up-to-date, reliable estimates of ecosystem services (Lu et al., 2022;Galaz García et al., 2023;Chaplin-Kramer et al., 2024). The proposed Global Biodiversity Observing System , which promises to streamline the process from data collection to detection and attribution of change (Gonzalez, Chase and O'Connor, 2023) to the production of indicators (CBD, 2024a), are only realisable if the appropriate tools are in place. ...

Reference:

Towards a unified ontology for monitoring ecosystem services
Integrated modeling of nature’s role in human well-being: A research agenda

Global Environmental Change

... This study contributes to the development of cultural routes in rural regions by analyzing the satisfaction of visitors and tourists, a key factor in improving the offerings of cultural routes. Given the ever-greater increase of outdoor activities in tourism [15], the development of cultural routes is viewed within the context of outdoor recreation which makes cultural routes particularly adaptable to a variety of tourist activities, as well as to various forms of the offering. Providing tourist experiences is vital to the long-term success of cultural route destinations, and although the tourist experience has been extensively studied, previous studies have not fully explained the specific factors shaping the cultural tourist experience in particular on cultural routes [16]. ...

The effect of forest composition on outdoor recreation

Journal of Environmental Management

... Pengukuran kesuksesan atau efektivitas sistem informasi sangat penting bagi suatu organisasi dalam pemahaman terhadap nilai dan kekuatan dari tindakan manajemen dan investasi sistem informasi. Metode pengukuran efektivitas perangkat lunak dapat menggunakan beberapa model, diantaranya: SEM, Path Analysis, dan SERV-QUAL [10], [11], [12]. SEM adalah metode statistik yang digunakan untuk menguji hubungan antara variabel-variabel laten dengan menggunakan data observasi. ...

Using structural equation models (SEM) to link climate change, forest composition, deer, and outdoor recreation

Ecological Modelling

... This broader relevance has positioned predictive biogeography as a critical discipline underpinning advancements and applications across a wide range of fields (Araújo and Peterson 2012). These include conservation biology (Araújo et al. 2011, Fordham et al. 2013, agriculture (Meynard et al. 2017, Gerber et al. 2024, Soubeyrand et al. 2024, forestry (Zhang et al. 2022, Rosa et al. 2024, fisheries (Cheung et al. 2010, Boavida-Portugal et al. 2018, epidemiology (Aliaga-Samanez et al. 2024, Mestre et al. 2024, and paleobiology (Metcalf et al. 2014, Mestre et al. 2022, reflecting its versatility in addressing contemporary and future global issues. ...

Global spatially explicit yield gap time trends reveal regions at risk of future crop yield stagnation

Nature Food

... In some reviews, biosphere reserves are excluded from the assessment of effectiveness [41][42][43] , concerning doubts as to whether they actually represent effective conservation action or merely bureaucratic labels 44 . Here we would like to emphasize the role that biosphere reserves could play as modern instruments for safeguarding the functioning of the biosphere -following a convivial conservation approach 45 , under a type of governance that includes people and their needs. ...

Mapping the planet’s critical areas for biodiversity and nature’s contributions to people

... The economic valuation of forest conservation also encompasses a multifaceted approach, revealing substantial benefits across various ecosystem services. Thakrar et al. (2024) underscored land-use decisions' significant air quality health effects, emphasizing the importance of integrating air quality considerations into policy assessments. Wang et al. (2024) highlighted the pivotal role of forests in enhancing water retention capacity, particularly in regions prone to water scarcity, suggesting the need for strategic land-use planning to balance urban development with ecosystem preservation. ...

Land-Use Decisions Have Substantial Air Quality Health Effects

Environmental Science and Technology

... For instance, the Netherlands and Iceland have decided to reflect the value of ecosystem services in national accounts (de Jongh et al., 2021, Cook et al., 2022. China is the first country to implement GEP and integrate the value of ecosystem services into decision-making processes alongside conventional macroeconomic indicators such as GDP (Ouyang et al. 2020;Zheng et al. 2023). ...

Gross ecosystem product (GEP): Quantifying nature for environmental and economic policy innovation

AMBIO A Journal of the Human Environment

... La eficiencia de aprovechamiento del N aplicado en los cultivos suele ser baja (< 50 %), en maíz los valores van de 35 a 75 % (Morris et al., 2018). Cuando este nutriente se desaprovecha, se pierde por lixiviación (nitrato), volatilización (amoníaco), desnitrificación (N 2 O y NO 2 ) y por escorrentía superficial (Goodkind et al., 2023). La eficiencia de recuperación del fertilizante nitrogenado aplicado depende de factores como el suelo (principalmente textura), precipitación (cantidad y distribución), régimen hídrico (temporal o riego), manejo de la fertilización (cantidad, fuente, oportunidad y forma de aplicación), cultivo (densidad y profundidad del sistema radical) y su manejo (Govindasamy et al., 2023). ...

Managing nitrogen in maize production for societal gain

PNAS Nexus

... SOC levels differ across broad spatial ranges, local scale variations in SOC can exert significant effects on sustainability by affecting the capacity of soils to sequester carbon and support ecosystem services (Hertel et al. 2023). The ANOVA unveiled a significant dissimilarity in SOC content within the studied forest types (F = 14.187, p = 0.04) where coniferous forests exhibited substantially higher levels compared to mixed forests (Fig. 4). ...

Focus on global-local-global analysis of sustainability

... In many cases, and for a range of environmental, socio-cultural and health values, however, some form of economic valuation will be possible. Guerry et al. (2023) provide some good examples of this, focusing on climate mitigation, cooling and health impacts of specific NBS in the cities of Guangzhou, China and Minneapolis, United States of America. The authors use a range of methods to assess value, also in monetary terms, including the InVEST model (Natural Capital Project, 2023). ...

Mapping, measuring, and valuing the benefits of nature-based solutions in cities