Solar radiation modification (SRM) presents important challenges to risk regulation and governance, arising from the array of multiple risks that SRM may influence. SRM would not simply reverse climate change, but could pose further ancillary impacts, depending on the method of SRM, such as stratospheric aerosol injection (SAI), marine cloud brightening (MCB), or a space-based planetary sunshade system (PSS). We identify multiple risks that SRM may influence, both biophysical and sociopolitical, to be compared to the multiple risks that may be affected by greenhouse gas (GHG) mitigation and climate adaptation. This multi-risk framework helps analysts and decision makers identify, evaluate, and compare multiple risks holistically; helps identify affected groups to overcome problems of disregard and omitted voice; helps compare policy options and map the array of risks to corresponding (or missing) governance mechanisms; and seeks risk-superior policies that would reduce multiple risks in concert. We then examine governance frameworks: uncoordinated, coordinated and comprehensive. We suggest two key mechanisms that can help build up from uncoordinated toward more coordinated or even comprehensive approaches, and that can gain support from SRM advocates, observers and critics alike: a series of international assessments of SRM, and a transparent international monitoring system for SRM.

Why do companies sometimes lobby legislators directly and sometimes act predominantly through business associations? Although economic factors, such as size and profitability, are well-known determinants of companies’ decision to lobby, they alone cannot explain the choice in lobbying strategies. This paper provides an explanation for why companies sometimes choose to lobby collectively: reputation. When firms want to lobby in favor of a publicly unpopular position, channeling their efforts through business associations can help them shield themselves from reputational consequences. To test this theory, this paper provides evidence from firms’ lobbying on climate change. Combining climate-friendliness ratings of corporate lobbying with an original survey experiment, it demonstrates the existence of reputational costs from lobbying alone and shows that lobbying through business associations helps firms avoid such costs. For the study of lobbying positions, these results imply important systematic differences in the positions firms take alone and collectively.

The international investment regime provides generous protections for foreign investors against adverse legal changes in host states, and unusually strong procedural rights to enforce those protections in investor-state dispute settlement (ISDS). Scholars have observed that the regime enables corporate capital accumulation and raises the costs of climate action, potentially deterring states from adopting ambitious climate policies. Building on this literature, we locate a key source of these concerns in the asymmetric treatment of state and investor behavior in ISDS, which allows investors to depict themselves as innocent victims of “unfair” and “unforeseeable” “political” processes, despite themselves being active political players and sophisticated political risk managers—a tactic we call feigned victimization. This tactic is employed by fossil fuel companies to achieve capital accumulation and climate obstruction goals. We illustrate our argument through an empirical case study of TC Energy’s US$15 billion ISDS claim against the United States in relation to the Biden Administration’s revocation of a permit required to construct the Keystone XL oil pipeline. Our case study also illustrates a method by which states can expose feigned victimization tactics by investors and incorporate evidence of this into their legal defenses in ISDS.

Shifting to cycling in urban areas reduces greenhouse gas emissions and improves public health. Access to street-level data on bicycle traffic would assist cities in planning targeted infrastructure improvements to encourage cycling and provide civil society with evidence to advocate for cyclists’ needs. Yet, the data currently available to cities and citizens often only comes from sparsely located counting stations. This paper extrapolates bicycle volume beyond these few locations to estimate street-level bicycle counts for the entire city of Berlin. We predict daily and average annual daily street-level bicycle volumes using machine-learning techniques and various data sources. These include app-based crowdsourced data, infrastructure, bike-sharing, motorized traffic, socioeconomic indicators, weather, holiday data, and centrality measures. Our analysis reveals that crowdsourced cycling flow data from Strava in the area around the point of interest are most important for the prediction. To provide guidance for future data collection, we analyze how including short-term counts at predicted locations enhances model performance. By incorporating just 10 days of sample counts for each predicted location, we are able to almost halve the error and greatly reduce the variability in performance among predicted locations.

Recent studies suggest that value orientations, both pro-environmental values and concerns and left–right ideology, strongly predict climate policy support in some settings, but not in others, and that institutional quality determines the strength of these associations. These studies are based on a limited number of countries and do not investigate the mechanisms at work nor what aspects of quality of government (QoG) matter more specifically. Analyzing data from 135 European regions across 15 countries, this paper finds that QoG moderates the relationships of pro-environmental values and left–right ideology with climate tax support and suggests that political trust is an underlying individual-level mechanism. Moreover, corruption seems to be the most important aspect of QoG for policy support. In regions where corruption is prevalent and trust in state institutions is low, support for climate taxes is low even among those who are generally concerned about the environment and climate change and who favor state intervention. The study suggests additional analyses, adopting quantitative and qualitative approaches, to inform policymakers on how to increase public support for climate taxation and improve policy designs to mitigate policy concerns across various segments of the population.

In the context of climate change, the impacts of extreme weather events are increasingly recognised as a significant threat to mental health in the UK. As clinicians and researchers with an interest in mental health, we have a collective responsibility to help understand and mitigate these impacts. To achieve this, however, it is vital to have an appreciation of the relevant policy and regulatory frameworks. In this feature article, a collaboration amongst mental health and policy experts, we provide an overview of the integration of mental health within current climate policies and regulations in the UK, including gaps and opportunities. We argue that current policy and regulatory frameworks are lacking in coverage, ambition, detail and implementation, as increases in weather extremes and their negative impacts on mental health outpace action. For example, across current national and local climate policies, there is almost no reference to the impacts of extreme weather events on mental health. Whilst alarming, this provides scope for future research to fill evidence gaps and inform policy and regulatory change. We call for mental health and policy experts to work together to improve our understanding of underlying mechanisms and develop practical interventions, helping to bring mental health within climate policy and regulatory frameworks.

This article scrutinizes the role of transparency in the United Nations Framework Convention on Climate Change (UNFCCC). Specifically, it examines a widely heard claim that ‘transparency is the backbone of the Paris Agreement’, and the assumption that mandatory transparency (reporting and review) is essential to fill potential gaps in climate action left by voluntary, nationally determined climate targets. We subject this claim to critical scrutiny by tracing the political contestations around the desired role of transparency in the UNFCCC, with a focus on mitigation-related transparency. Our analysis shows that, despite developing countries expressing concerns during the pre-Paris negotiations, the Paris Agreement's enhanced transparency framework (ETF) is almost exclusively ‘enhanced’ (compared with earlier provisions) for developing countries, with some instances of regression for developed countries. Furthermore, the effects of such enhanced reporting are not straightforward and might de facto have an impact on countries’ autonomy to nationally determine their mitigation targets in diverse ways, even as all the detailed reporting does not facilitate comparability of effort. With implementation of the ETF due to start in 2024, our analysis provides a timely exploration of the extent to which transparency is really a backbone of the Paris Agreement, and for whom and with what implications for ambitious action from all under the international climate regime. It calls into question whether the transformative potential of transparency, much extolled within the UNFCCC process, will materialize for all countries in a similar manner or rather will have an impact on countries differentially.

Turkey’s Europeanization process provides a particularly interesting case study of the extra-jurisdictional impact of European Union (EU) law, both through policy convergence and through the so-called Brussels effect. Formally, Turkey must adopt certain EU rules due to its status as an EU candidate country, but its candidacy process has been lengthy and uncertain, resulting in partial and uneven adoption of EU rules. Nevertheless, EU-style policymaking has persisted in various policy areas, including environmental and climate policy. This paper aims to analyze the convergence of climate change policies between the EU and Turkey by employing multidimensional scaling, a method that enables the visualization and examination of the connectivity and intensity of cooperation between states. For the period from 2007 to 2023, our comparative analysis demonstrates that policy divergence occurs when the EU’s share of Turkey’s total trade decreases and when political challenges are experienced. On the other hand, periods of policy convergence coincide with periods of increased trade volume and expanded trade opportunities. The results suggest that through its market size and regulatory capacity, the EU exerts soft power which forces Turkey to align its climate policies with the EU to protect and maintain its competitiveness in the European marketplace.

Why do citizens support or reject climate change mitigation policies? This is not an easy choice: citizens need to support the government in making these decisions, accept potentially radical behavior change, and have altruism across borders and for future generations. A substantial literature argues that political trust facilitates citizen support for these complex policy decisions by mitigating the cost and uncertainty that policies impose on individuals and buttressing support for government intervention. We test whether this is the case with a pre-registered conjoint experiment fielded in Germany in which we vary fundamental aspects of policy design that are related to the cost, uncertainty, and implementation of climate change policies. Contrary to strong theoretical expectations and previous work, we find no difference between those with low and high trust on their support for different policy attributes, assuaging the concern that low and declining trust inhibits climate policymaking.

Last year saw yet another year of weather extremes. The Copernicus Climate Change Service run by the European Centre for Medium-Range Weather Forecasts on behalf of the European Commission (Copernicus, 2024) measured 2023 as being globally the warmest year since records began in 1850. This was by a large margin (0.17 per cent) over the previous record in 2016, with global surface air temperature at nearly 1.5°C above pre-industrial levels. While last year’s observations embodied an El Niño effect, which every few years sees temperatures affected by warmer waters coming to the surface of the tropical eastern Pacific Ocean, changes and anomalies consistently observed over the last few years across the globe are becoming more pronounced. What is commonly labelled “climate change” is turning into a global climate emergency. No economy or society are immune to its effects. Today, we see the global average temperature at over 1.1°C above pre-industrial levels, a rise that has been extraordinarily rapid on a planetary timescale, and one that has been primarily caused through our (humans) burning fossil fuels. Nearly a decade has passed since the United Nations’ Climate Change Conference in 2015, COP21, where 196 nations adopted The Paris Agreement – a legally binding international treaty on climate change. Its goal was to hold “the increase in the global average temperature to well below 2°C above pre-industrial levels” and to pursue efforts “to limit the increase to 1.5°C”.