Conservation actions often rely on expert knowledge. Ensuring that expert elicitation is broadly inclusive, analyzed rigorously, and cost effective is challenging. Discrete choice experiments (DCEs) with experts present an opportunity to measure the preferences individuals with technical knowledge hold for the provision of public goods. We present a novel approach that combines machine learning, language models, and an email campaign to reach over two thousand experts with a record of peer-reviewed publication. We apply this approach to understand the preferences experts ( n = 2 731) have for natural climate solutions (NCSs) that focus on ecosystem restoration. We found that experts have a collective preference for distributing funding across a variety of actions rather than concentrating on specific restoration actions. In addition, experts preferred that restoration take place in lower-income contexts, highlighting the important role such NCS can play in promoting human well-being in marginalized regions with lower opportunity costs for land. These preferences were robust to experts’ area and regional expertise, supporting the conclusion that their preferences did not narrowly reflect private interests. Overall, our research demonstrates how DCEs can synthesize expert knowledge to inform complex problems around provisioning public goods for conservation.

Forests regulate global and local climates in ways that impact human well-being. In this Review, we discuss the scale-dependent mechanisms through which forests regulate climate, highlighting their contributions to global mitigation and local adaptation. Locally, forests tend to buffer temperatures, cooling in warm conditions and warming in cold ones. In regions that naturally support dense forest cover, trees contribute to global cooling primarily through carbon uptake, with some offsetting from albedo-related warming. By enhancing rainfall interception, evapotranspiration, and cloud formation, forests also influence the hydrological cycle, lowering flood risks in humid regions but often reducing downstream water availability, especially in drier climates. Collectively, these interacting processes show that the greatest climate benefits occur where forests are native, highlighting their importance for both climate adaptation and mitigation.

Despite national and international commitments to food systems transformation and an increasing adoption of common indicators, no comprehensive targets have been established against which progress can be measured. Here, building on the Food Systems Countdown Initiative framework, we identify existing targets-based on internationally agreed commitments and normative goals-and establish benchmarks-based on empirically derived peer performance reference values at the global, regional and income group levels-for 44 Food Systems Countdown Initiative indicators. We also assess countries' historical progress and the rate of change required to achieve targets and benchmarks over two different timescales. We show that current progress is insufficient to meet 2030 targets and benchmarks at global level. Comparing countries' status to regional and income benchmarks, which are generally less ambitious, yields better performance across indicators and regions, although gaps remain. Achieving most targets and benchmarks by 2050 is possible if countries correct course and accelerate progress, but certain indicators will require considerable investment and intervention.

Carbon markets reward the climate mitigation benefits of nature-based solutions but rarely value their broader societal impacts. Creating markets for verified co-benefits, such as coastal protection and biodiversity, could redirect investment towards projects that deliver larger gains for both people and climate.

Wildland fire activity has increased across many regions of the United States, raising concerns about smoke exposure and the health impacts of fine particulate matter (PM2.5). Former studies on environmental disparities show smoke impacts vary across communities and regions, but most studies focus on non-spatial factors (e.g., income, race/ethnicity), potentially overlooking the spatial dimension of smoke exposure disparities. We advance this literature by assessing a location's resilience with spatial aspects of wildland fire smoke exposure for two spatial variables: wildland urban interface (WUI) category and land ownership. We have four research objectives: 1) to identify areas with higher exposure to wildland fire PM2.5, 2) to identify areas with greater demographic or socioeconomic vulnerability, 3) to calculate increases in unhealthy air quality days, and 4) to measure the size of the population with high smoke exposure and high vulnerability. We found Native American reservations experience 0.15-0.32 mu g/m(3) higher average daily PM2.5 from wildland fire smoke, along with lower adaptive capacity, higher sensitivity, and higher vulnerability than other land ownership areas. WUI areas also showed at least 60 % higher increase in moderate air quality days (12-35 mu g/m(3)) and greater sensitivity than non-WUI areas. Most importantly, higher vulnerability areas, defined by the lowest adaptive capacity (>= 95th percentile), highest sensitivity (>= 95th percentile), and highest overall vulnerability (>= 95th percentile), had a higher increase in the number of moderate (12-35 mu g/m(3)) and unhealthy air quality days (>35 mu g/m(3)) compared to their counterparts. These findings provide insights for community-led decision-making, resource allocation, fire management strategies, and public health interventions.

Due to complex interactions, changes in any one area of food systems are likely to impact-and possibly depend on-changes in other areas. Here we present the first annual monitoring update of the indicator framework proposed by the Food Systems Countdown Initiative, with new qualitative analysis elucidating interactions across indicators. Since 2000, we find that 20 of 42 indicators with time series have been trending in a desirable direction, indicating modest positive change. Qualitative expert elicitation assessed governance and resilience indicators to be most connected to other indicators across themes, highlighting entry points for action-particularly governance action. Literature review and country case studies add context to the assessed interactions across diets, environment, livelihoods, governance and resilience indicators, helping different actors understand and navigate food systems towards desirable change.

Addressing global environmental conservation problems requires rapidly translating natural and conservation social science evidence to policy-relevant information. Yet, exponential increases in scientific production combined with disciplinary differences in reporting research make interdisciplinary evidence syntheses especially challenging. Ongoing developments in natural language processing (NLP), such as large language models, machine learning (ML), and data mining, hold the promise of accelerating cross-disciplinary evidence syntheses and primary research. The evolution of ML, NLP, and artificial intelligence (AI) systems in computational science research provides new approaches to accelerate all stages of evidence synthesis in conservation social science. To show how ML, language processing, and AI can help automate and scale evidence syntheses in conservation social science, we describe methods that can automate querying the literature, process large and unstructured bodies of textual evidence, and extract parameters of interest from scientific studies. Automation can translate to other research agendas in conservation social science by categorizing and labeling data at scale, yet there are major unanswered questions about how to use hybrid AI-expert systems ethically and effectively in conservation.

Abstract Social media plays an outsized role in information dissemination, issue mobilization, and public influence. For environmental nongovernmental organizations (“eNGOs”), social media plays a critical role in fundraising and inspiring engaged audiences using rich media and punchy taglines. Yet, there is little to no accounting of whether and how eNGOs have adopted social media, limiting analyses of how eNGOs are leveraging social media to develop effective communication strategies and campaigns. We analyzed the social media presence of over 100 eNGOs. We evaluated which platforms are used by eNGOs and differences between them in terms of their visibility on social media. 88%–97% of the eNGOs in our sample use four out of the five leading social media platforms. There were marked differences across eNGOs and platforms in terms of public visibility, represented by the number of followers. eNGOs focusing on advocacy, aquatic environments, and species conservation had significantly larger numbers of followers. Our findings indicate that conservation can make more headway on newer, more visually‐oriented platforms that also have stronger youth traction. We use our analyses to identify which eNGOs have much larger followings on social media than expected. These leaders can provide lessons on how eNGOs can enhance their social media impact.

Nature-based solutions (NBS) can deliver many benefits to human wellbeing, including some crucial to climate adaptation. We quantitatively assess the global potential of NBS strategies of protection, restoration, and agroforestry by modeling global climate change mitigation and local ecosystem services (water availability, sediment retention, runoff, pollination, nitrogen retention, green water storage, and coastal protection). The strategies with the most potential to help people do not necessarily deliver the most climate change mitigation: per area of conservation action, agroforestry provides substantial benefits (>20% increase in at least one local ecosystem service) to three times more people on average than reforestation while providing less than one tenth the carbon sequestration per unit area. Each strategy delivers a different suite of ecosystem service benefits; for instance, avoided forest conversion provides a strong increase in nitrogen retention (100% increase to 72 million people if fully implemented globally) while agroforestry increases pollination services (100% increase to 3.0 billion people if fully implemented globally). One common disservice shared by all the NBS strategies modeled here is that increased woody biomass increases transpiration, reducing annual runoff and in some watersheds negatively impacting local water availability. In addition, the places with the greatest potential for climate change mitigation are not necessarily the ones with the most people. For instance, reforestation in Latin America has the greatest climate change mitigation potential, but the greatest ecosystem service benefits are in Africa. Focusing on nations with high climate mitigation potential as well as high local ecosystem service potential, such as Nigeria in the case of reforestation, India for agroforestry, and the Republic of Congo for avoided forest conversion, can help identify win-win sites for implementation. We find that concentrating implementation of these three conservation strategies in critical places, covering 5.8 million km2, could benefit 2.0 billion people with increased local ecosystem services provision. These critical places cover only 35% of the possible area of implementation but would provide 80% of the benefits that are possible globally for the selected set of ecosystem services under the NBS scenarios examined here. We conclude that targeting these critical places for protection, restoration, and agroforestry interventions will be key to achieving adaptation and human wellbeing goals while also increasing nature-based carbon mitigation.

As wildfires continue to worsen across western United States, forest managers are increasingly employing prescribed burns as a way to reduce excess fuels and future wildfire risk. While the ecological benefits of these fuel treatments are clear, little is known about the smoke exposure tradeoffs of using prescribed burns to mitigate wildfires, particularly among at-risk populations. Outdoor agricultural workers are a population at increased risk of smoke exposure because of their time spent outside and the physical demands of their work. Here, we assess the smoke exposure impacts among outdoor agricultural workers resulting from the implementation of six forest management scenarios proposed for a landscape in the Central Sierra, California. We leverage emissions estimates from LANDIS-II to model daily PM _2.5 concentrations with the Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT) and link those to agricultural employment data from the Bureau of Labor Statistics. We find a u-shaped result, in that moderate amounts of prescribed burning result in the greatest reduction in total smoke exposure among outdoor agricultural workers, particularly during months of peak agricultural activity due to wildfire-specific smoke reductions. The reduction in total smoke exposure, relative to scenarios with the least amount of management, decreases as more prescribed burning is applied to the landscape due to the contributions of the fuel treatments themselves to overall smoke burden. The results of this analysis may contribute to preparedness efforts aimed at reducing smoke exposures among outdoor agricultural workers, while also informing forest management planning for this specific landscape.

Natural climate solutions (NCS) play a critical role in climate change mitigation. NCS can generate win–win co-benefits for biodiversity and human well-being, but they can also involve trade-offs (co-impacts). However, the massive evidence base on NCS co-benefits and possible trade-offs is poorly understood. We employ large language models to assess over 2 million published journal articles, primarily written in English, finding 257,266 relevant studies on NCS co-impacts. Using machine learning methods to extract data (for example, study location, species and other key variables), we create a global evidence map on NCS co-impacts. We find that global evidence on NCS co-impacts has grown approximately tenfold in three decades, and some of the most abundant evidence relates to NCS that have lower mitigation potential. Studies often examine multiple NCS, indicating some natural complementarities. Finally, we identify countries with high carbon mitigation potential but a relatively weak body of evidence on NCS co-impacts. Through effective methods and systematic and representative data on NCS co-impacts, we provide timely insights to inform NCS-related research and action globally. Rich evidence of the potential co-benefits and trade-offs of natural climate solutions is available but remains poorly understood. Assessing the literature with machine learning methods, this study maps and analyses the growing evidence of trade-offs in natural climate solutions globally.

Environmental governance occurs through and is shaped by communication. We propose a typology of public communication, classifying it by directionality (one-way or two-way) and objective (informational or operational). We then review how communication types influence individuals’ cognitive frames, values, and environmental behaviors. Though one-way communication is common, its impact is often limited to influencing cognitive frames. Research on two-way informational communication demonstrates a greater ability to align cognitive frames and values among individuals, and research on two-way operational communication demonstrates the greatest impact on conceptual frames, values, and environmental behaviors. Factors that affect the impact of communication include the medium through which it occurs, trust, timing, and social-material context. Among these, our review considers new directions in public communication research that focus on the role of digital platforms, misinformation, and disinformation. We conclude by synthesizing research on deliberative communication, a case of communication among citizens guided by democratic ideals.

Household solid fuel use has adverse impacts on health and the environment. The Indian government's Pradhan Mantri Ujjwala Yojana (PMUY) subsidy promoted the adoption of Liquid Petroleum Gas (LPG) by millions of Indian households. There is little knowledge, however, regarding decision-making to reduce solid fuel use after adopting cleaner fuels. Leveraging panel data on household energy use in rural India we jointly estimated LPG adoption and consumption to study the reduction in solid fuel use. Our results indicate that exclusive LPG use increased from 4.5% to 17.8% between 2015 and 2018 while fuel stacking (use of multiple fuels) doubled from 18% to 39%. The household's wealth index, self-reported higher social strata, business ownership, head of household's educational level, and the proportion of LPG-using households in the village were positively associated with LPG consumption and suspension of solid fuels. Distance to LPG refill delivery, household size and PMUY subsidy were negatively associated with LPG share though LPG share was positively associated with the interaction of PMUY with wealth index. Policy efforts should target sustained LPG consumption by making refill delivery more accessible and implementing a pro-poor refill subsidy as well as general poverty alleviation (e.g., by creating income generation opportunities).

Prescribed burning can mitigate extreme wildfire risk and reduce total smoke emissions. Yet prescribed burns’ emissions may also contribute to smoke exposures in nearby communities. Incorporating public health considerations into forest management planning efforts may help reduce prescribed burn-related exposure impacts. We present a methodological framework linking landscape ecology, air-quality modelling and health impact assessment to quantify the air-quality and health impacts of specific management strategies. We apply this framework to six forest management scenarios proposed for a landscape in the Central Sierra, California. We find that moderate amounts of prescribed burning can decrease wildfire-specific PM 2.5 exposures and reduce asthma-related health impacts in the surrounding region; however, the magnitude of that benefit levels off under scenarios with additional prescribed burning because of the added treatment-related smoke burdens. This framework can be applied to other fire-prone landscapes to incorporate public health considerations into forest management planning.

Natural climate solutions can mitigate climate change in the near-term, during a climate-critical window. Yet, persistent misunderstandings about what constitutes a natural climate solution generate unnecessary confusion and controversy, thereby delaying critical mitigation action. Based on a review of scientific literature and best practices, we distill five foundational principles of natural climate solutions (nature-based, sustainable, climate-additional, measurable, and equitable) and fifteen operational principles for practical implementation. By adhering to these principles, practitioners can activate effective and durable natural climate solutions, enabling the rapid and wide-scale adoption necessary to meaningfully contribute to climate change mitigation.

Forests play a crucial role in regulating the global climate. Yet, forests also influence the local climate conditions through biophysical processes that directly impact human wellbeing. With growing policy emphasis on these climate adaptation effects, we review the scale dependent impacts of forests on climate conditions and their implications for human wellbeing. Generally, existing forests buffer local temperatures, with warming effects in cold regions and cooling effects in hot regions. At a global scale, trees are more conducive to cooling in regions where dense forests would naturally exist. Additionally, forests generally reduce water runoff, which can reduce flooding in wet areas, but it can also limit water availability downstream, especially in drier regions. Together, these findings suggest that climate positive tree effects tend to be most frequent in regions where forests naturally occur, and highlight the growing consensus around the importance of natural forests for climate adaptation.

Over a billion outdoor workers live in the tropics, where nearly a fifth of all hours in the year are hot and humid enough to exceed recommended safety thresholds for workers conducting heavy labor. Reviews have focused on heat impacts on worker health, well-being, and productivity, but synthesis on how to increase resilience to heat for outdoor workers is lacking. Here we assess current and future heat exposure in the tropics and review four bodies of literature on heat impacts on workers. We also synthesize knowledge about mitigation and adaptation uncertainties as well as the actions that can be taken to strengthen worker resilience. We show that under an additional 1 degrees C of warming, - 800 million people in the tropics will live in areas where heavy work should be limited for over half of the hours in the year. Our review provides primary, secondary, and tertiary solutions that will inform policies and practices as well as research that is needed to bolster worker resilience and well-being.

The Indian government promoted the adoption of LPG by millions of poor households through targeted Pradhan Mantri Ujjwala Yojana connection subsidies. However, there is no empirical study on the impact of LPG adoption and usage on cooking energy efficiency. It is important to analyze the causal impact of LPG usage on cooking energy efficiency to help estimate the energy saving resulting from fuel-switching and understand the implications for the improvement of the environment, health, and socioeconomic outcomes. This paper leverages panel data on rural household energy use from the Access to Clean Cooking Energy and Electricity - Survey of States survey to evaluate the impact of the share of LPG consumption on overall cooking energy efficiency in 5,590 [n = 1,538 in 2015 and n = 4,052 in 2018] LPG adopters. To account for the potential endogeneity posed by the share of LPG consumption on our dependent variable, we used the village-level fraction of households who report the use of LPG as the main source of cooking fuel as an instrumental variable. We find a statistically significant impact of LPG consumption share on improved household cooking energy efficiency. A 10 % increase in the share of LPG reduces the total useful energy consumed by 9 % and the final energy consumed by 23 %. The extrapolated result indicates that the shift by all partial LPG user households in rural India in 2018 to exclusive (100 %) use of LPG will save about 81 million tonnes of firewood or 3.34 % of India's primary energy consumption. A propoor subsidies for LPG refill and other policy measures that encourage households to shift to more exclusive use of LPG can reduce overall household energy consumption which is expected in turn to help achieve the environmental and health benefits of improved energy efficiency.

The impact of smoke from wildland fires on communities across the western United States is an interdisciplinary crisis that requires an interdisciplinary solution. There are increasing calls for cross-collaboration between forest, fire, air quality, and public health practitioners to best prepare communities for ever-worsening smoke seasons. However, opportunities to engage interdisciplinary groups of practitioners and stakeholders on this topic have been largely missing. We report on the development and implementation of a hybrid in-person and online workshop that brought together practitioners from Washington State to foster new interdisciplinary relationships and partnerships in order to integrate public health considerations into forest management during and beyond fire season. This workshop highlighted ways in which hybrid workshops can facilitate discussions across traditionally siloed stakeholders to address the community health crisis of wildfire smoke and illuminate tangible steps for further facilitating integrated discussions around a shared area of interest. Key lessons included the importance of introductory meetings for establishing strong collaborations and the strength of hybrid settings for fuller participation by diverse stakeholders. This manuscript outlines ways in which local practitioners from other smoke-impacted communities can begin to build and utilize interdisciplinary partnerships to prepare and adapt for longer and more severe wildland fire smoke seasons.