Urban agglomeration (UA), as a model of regional integration, provides a platform for advancing sustainable urban development and carbon emission reduction. Treating the urban agglomeration implementation in China as a quasi-natural experiment, we use the high-speed rail (HSR)-weighting spatial difference-in-differences (SDID) method to examine both the direct and indirect effects of UA on carbon emission reduction. Using a balanced panel data set of 195 cities from 2004 to 2019 in China, our empirical results show that UA directly impacts carbon emission abatement in core cities and indirectly affects neighboring cities through inter-city HSR connections. Furthermore, the mechanism analysis suggests that: (1) UA reduces carbon emissions by upgrading industrial structures, generating a “borrowed-size” effect that promotes structural optimization and reduces carbon emissions in neighboring cities; (2) UA reduces carbon emissions by decreasing energy intensity, but the resulting siphon effect increases energy consumption in neighboring cities; (3) UA promotes local carbon emission reduction by stimulating technological innovation and diversification agglomeration, but does not influence carbon emissions in neighboring cities through these mechanisms. These findings provide useful insights into how UA and inter-city HSR facilitate the transition towards a low-carbon society.

The adoption of climate-smart agriculture (CSA) practices is crucial for reducing greenhouse gas emissions, enhancing resilience, and improving soil health in the U.S. agricultural sector. This study investigates the drivers of CSA adoption in U.S. farming, focusing on United States Department of Agriculture (USDA) programs between 2006 and 2023. Using a probit model, we evaluate the impact of state-level incentives, including crop insurance premium discounts and carbon trading schemes, and the role of climate-smart terminology. Results show that crop insurance discounts and carbon trading programs are associated with 4.3 and 6.9 percentage-point increases in adoption probability, respectively. The ‘climate-smart’ label is associated with slower adoption growth, particularly in politically conservative regions. Adoption likelihood is higher in states dominated by row and specialty crops, while larger farms show lower adoption likelihood. These findings emphasise the importance of financial incentives, regional variability, and synergistic policy framing in promoting CSA adoption within large-scale agricultural policy such as the Farm Bill in the U.S. and the Common Agricultural Policy (CAP) in the E.U.

This research employs high-dimensional fixed-effects model to investigates the effect of climate policy uncertainty on firms' green innovation vitality and its mechanism role using data from Chinese listed companies from 2000 to 2022. Our empirical findings indicate that climate policy uncertainty hampers green innovation vitality of listed firms, and rising climate policy uncertainty negatively affects green innovation vitality. The results from heterogeneity analyses reveal that this negative effect is significant in Eastern and Central, SOEs and manufacturing firms. The mechanism analysis further indicates that climate policy uncertainty exerts an inhibitory effect on firms' green innovation vitality by intensifying corporate financing constraints and reducing green governance level. The inhibitory impact of Chinese climate policy uncertainty on green innovation vitality is moderated by digital transformation of companies and green funding incentives. The results of the double hurdle model suggest that once firms have decided to enter the field of green innovation, this decision is less likely to be altered by changes in climate policy uncertainty. However, among firms that have already chosen to engage in green innovation, heightened climate policy uncertainty significantly diminishes firms' green innovation vitality.

A key factor undermining the credibility of carbon offsets is the evaluation of project baselines and their impact. The ex ante scenarios constructed by project developers in accordance with rules set by certification schemes have been challenged by ex post evaluations from scientists, who frequently document cases of credit allocations that overestimate the actual emission reductions. Increasing credibility requires methodologies that reliably measure project outcomes and prevent overcrediting—an objective that ex post evaluations may be well suited to achieve. We explore how systematic ex post evaluations could restore credibility to certification schemes in the voluntary carbon market. Inaccuracies in the evaluation of project impacts, even under ex ante scenarios, can cause overestimation or underestimation of carbon offsets. This study shows the potential of systematic ex post evaluations to enhance the credibility of voluntary carbon market schemes.

In 2000 China launched the Natural Forest Protection Program (NFPP) as its flagship initiative for forest conservation and restoration, targeting both state-owned forestland managed by state-owned forest enterprises (SOFEs) and large areas of forestland held by village households. This study evaluates the overall impact of the NFPP on forest cover and examines the program's heterogeneous effects across property right regimes and provinces using a spatial regression discontinuity design. Our analysis reveals that forest cover within NFPP boundaries is, on average, about 6 % higher than in adjacent areas. Notably, collective forestland experiences an 82 % greater treatment effect compared to state-owned forests - even though collective areas receive less direct financial support - underscoring the role of institutional and local governance factors. Furthermore, our findings highlight significant regional variations in program outcomes. Overall, the NFPP exemplifies a proactive approach to reversing deforestation amidst rapid economic development, and our results offer valuable insights for refining policy measures and ensuring equitable funding strategies across diverse forest management regimes.

Carbon offset projects aimed at avoiding deforestation and forest degradation, generally labeled "REDD+," are frequently promoted as a pivotal tool to mitigate climate change, promising to offer additional co-benefits for biodiversity and local communities. Despite this optimism, most positive impacts claimed by these initiatives in the voluntary carbon market (VCM) lack empirical support and are instead based on the hopeful narratives of stakeholders with clear conflicts of interest. We critically examine the scientific theories, concepts, and evidence regarding VCM's REDD+ projects, highlighting limitations on the quantification of their purported benefits that are inherent to the current design of carbon markets. Independent studies consistently point to shortcomings in the rigor and credibility of crediting methodologies and other procedures, which market players have been slow or reluctant to address. There is accumulating evidence that projects' climate and social impacts are often exaggerated due to a range of technical and practical shortcomings. We hope this work clarifies widespread misconceptions associated with REDD+ projects in the VCM and assists organizations and policymakers in their efforts to meaningfully mitigate climate change.

To mitigate the substantial losses incurred by air pollution, individuals undertake defensive behaviors in the form of health insurance expenses. Leveraging data from the 2011-2017 China Household Finance Survey (CHFS) encompassing 3033 residents, we estimate the causal impact of air pollution on defensive expenditures. Our findings are as follows: (1) Air pollution exhibits a significantly favorable effect on individual commercial health insurance expenses, with a 1% increase in PM2.5 concentration correlating to an 11.02% rise in personal commercial health insurance expenditure. (2) Demographics such as younger individuals, married populations, lower educational attainment cohorts, and urban residents, displaying higher sensitivity to air pollution, tend to purchase more insurance coverage. (3) Risk perception emerges as a pivotal channel through which air pollution affects commercial health insurance expenditure. Our conclusions underscore the significance of risk perception in defensive expenditures, thereby optimizing individual risk mitigation strategies.

Carbon markets play an important role in firms' and governments' climate strategies. Carbon crediting mechanisms allow project developers to earn carbon credits through mitigation projects. Several studies have raised concerns about environmental integrity, though a systematic evaluation is missing. We synthesized studies relying on experimental or rigorous observational methods, covering 14 studies on 2346 carbon mitigation projects and 51 studies investigating similar field interventions implemented without issuing carbon credits. The analysis covers one-fifth of the credit volume issued to date, almost 1 billion tons of CO2e. We estimate that less than 16% of the carbon credits issued to the investigated projects constitute real emission reductions, with 11% for cookstoves, 16% for SF6 destruction, 25% for avoided deforestation, 68% for HFC-23 abatement, and no statistically significant emission reductions from wind power and improved forest management projects. Carbon crediting mechanisms need to be reformed fundamentally to meaningfully contribute to climate change mitigation. Carbon markets are key in climate strategies, but only 16% of carbon credits represent real emission reductions, based on a study of 2,346 projects. Reforms are needed to improve the effectiveness of carbon crediting mechanisms in addressing climate change.

We conducted a large-scale online experiment to examine whether climate change messaging can induce emotions and motivate pro-environmental action. We study how exposure to explicit positive (‘warm glow’) and negative (‘cold prickle’) emotional appeals as well as a traditional social norm communication affects pro-environmental action. We find that a simple call to take action to mitigate climate change is at least as affective as social norm message framing and emotional appeals. Our results highlight the difficulty of designing messaging interventions that effectively harness emotional incentives to promote pro-environmental action. Messages that explicitly emphasise the personal emotional benefits of contributing to environmental causes or the adverse emotional effects of not doing so seem to fall short of motivating pro-environmental effort. Our findings underscore the need for caution when incorporating emotive appeals into policy interventions.

How best to incentivize land managers to achieve conservation goals in an economically and ecologically effective manner is a key policy question that has gained increased relevance from the setting of ambitious new global targets for biodiversity conservation. Conservation (reverse) auctions are a policy tool for improving the environmental performance of agriculture, which has become well-established in the academic literature and in policy making in the US and Australia. However, little is known about the likely response of farmers to incentives within such an auction to (1) increase spatial connectivity and (2) encourage collective participation. This paper presents the first framed field experiment with farmers as participants that examines the effects of two features of conservation policy design: joint (collective) participation by farmers and the incentivization of spatial connectivity. The experiment employs farmers in China, a country making increasing use of payments for ecosystem services to achieve a range of environmental objectives. We investigate whether auction performance-both economic and ecological-can be improved by the introduction of agglomeration bonus and joint bidding bonus mechanisms. Our empirical results suggest that, compared to a baseline spatially coordinated conservation auction, the performance of an auction with an agglomeration bonus, a joint bidding bonus, or both, is inferior on two key metrics-the environmental benefits generated and cost effectiveness realized.

The credibility of carbon offset mechanisms is threatened by many issues related to their true effectiveness. We advocate that these issues cannot be effectively addressed without a dramatic improvement in transparency across the entire value chain of carbon offsetting, a crucial step for achieving a reduction in carbon emissions. Designing and implementing effective carbon offset mechanisms is a complex and challenging process. This Perspective underscores the importance of transparency across the carbon-offsetting value chain and places it as a prerequisite for efficient offset mechanisms and, ultimately, carbon emissions reduction.

Carbon offsets from the REDD+ (reducing emissions from deforestation and degradation) framework to protect forests are expected to see a 100-fold increase in market value by 2050. However, independent causal impact evaluations are scarce and only a few studies assess benefits to communities themselves, a core objective of REDD+. Following a pre-analysis plan, we use a before-after-control-intervention (BACI) framework to evaluate the impact of a large-scale voluntary REDD+ project in Sierra Leone—the Gola project. We use a panel of both satellite images and household surveys to provide causal evidence of the impact of the project on local deforestation rates and socioeconomic indicators over the first 5 yr of its implementation. We find that REDD+ slowed deforestation by 30% relative to control communities while not changing economic wellbeing and conservation attitudes. We find suggestive evidence that the programme increased the value of alternative income sources, by shifting labour away from forest-dependent farming activities. A cost-to-carbon calculation shows that REDD+ led to 340,000 tCO2 in avoided emissions per year, with an estimated cost of US$1.12 per averted tCO2. Our study contributes to developing an evidence base for voluntary REDD+ projects and offers a robust approach to carry out BACI assessments. Independent impact evaluations of voluntary REDD+ projects to protect forests are needed to provide evidence of their effects. This study evaluates the impacts of a large voluntary REDD+ project in Sierra Leone and finds evidence of slowing deforestation with no socioeconomic harm to local people.

To achieve sustainable development, there is widespread of the need to protect natural resource and improve government oversight in achieving China's economic security and ecological civilization. Compilation of natural resources balance sheet (NRBS) and enhancement of resources management are becoming an important topic in China. How to compile NRBS to affix the responsibility for government and officials for inadequate supervision is still not resolved satisfactorily. This paper proposes the NRBS to enable governments to identify the importance of natural resource restoration and to hold leading cadres accountable for a lack of adequate supervision. The NRBS consist of three accounts: natural resource assets, natural resource liabilities, and net worth. Important components of the NRBS for the liabilities account with a property rights regime are developed to measure and assign responsibility. The compilation of an NRBS is applied to the Chinese province of Shaanxi as an illustration to demonstrate that the accounting framework and the compilation steps are tractable using financial methods and available data. The accounting results of natural resource assets and liabilities unveil the threat to resource management and the policy implications to government and officials. Finally, the advantages and limitations of NRBS are discussed.

This study examines the effects of technology patents, environmental policy stringency, and political globalization on green energy markets and energy transitions in 18 OECD countries from 1990 to 2022. Two models—one focusing on renewable energy and the other on non-renewable energy—were analyzed using Method of Moments Quantile Regression (MMQR), which accounts for outliers and nonlinear relationships. The results demonstrate that technological advancement and stringent environmental policies promote the adoption of renewable energy. Additionally, political globalization shows a positive correlation with green energy while negatively impacting fossil fuel use. The study offers policy recommendations for advancing green energy transitions aligned with the net-zero carbon agenda.

Teams play a key role in tackling complex societal challenges, such as developing vaccines or novel clean energy technologies. Yet, the effect of air pollution on team performance in non-routine problem-solving tasks is not well explored. Here, we document a sizable adverse effect of air pollution on team performance using data from 15,000 live escape games in London, United Kingdom. On high-pollution days, teams take on average 5% more time to solve a sequence of non-routine analytical tasks, which require collaborative skills analogous to those needed in the modern workplace. Negative effects are non-linear and only occur at high levels of air pollution, which are however commonplace in many developing countries. As team efforts predominantly drive innovation, high levels of air pollution may significantly hamper economic development.

1 Environmental Geography Group, Institute for Environmental Studies (IVM), VU University Amsterdam, Amsterdam, The Netherlands 2 Centre for Environment, Energy and Natural Resource Governance, University of Cambridge, Cambridge, United Kingdom 3 European Forest Institute (EFI), Barcelona, Spain 4 Center for International Forestry Research (CIFOR), Lima, Peru 5 Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, USA 6 Center for Development Research (ZEF), University of Bonn, Bonn, Germany 7 Institute for Food and Resource Economics (ILR), University of Bonn, Bonn, Germany 8 ARC Centre of Excellence for Climate Extremes, University of New South Wales, Sydney, Australia 9 Department of Land Economy, University of Cambridge, Cambridge, UK

Carbon offsets from voluntary avoided-deforestation projects are generated on the basis of performance in relation to ex ante deforestation baselines. We examined the effects of 26 such project sites in six countries on three continents using synthetic control methods for causal inference. We found that most projects have not significantly reduced deforestation. For projects that did, reductions were substantially lower than claimed. This reflects differences between the project ex ante baselines and ex post counterfactuals according to observed deforestation in control areas. Methodologies used to construct deforestation baselines for carbon offset interventions need urgent revisions to correctly attribute reduced deforestation to the projects, thus maintaining both incentives for forest conservation and the integrity of global carbon accounting.