International law and global governance regimes for environmental health challenges have been slow to reflect the intertwined relationship between the environment and human health. Historical legacies have caused artificial fragmentation between the two that has resulted in distinct fields of international law and institutions for the environment and health. However, new global paradigms for thinking about environmental health have emerged to foster synthesis under global health law, including One Health and Planetary Health approaches, as well as through international human rights law like the recognition of the right to a clean, safe, and healthy environment. Guided by equity, new international law and global governance reforms, including the proposed Pandemic Agreement and Plastics Treaty, are opportunities to synthesize the intersecting dimensions of the environment and global health. However, future paths towards cohesion must explicitly incorporate human rights in environmental health governance, including the rights of Indigenous Peoples, while actively addressing inequities in global health law, between and within countries, and across generations.

Calcifying macroalgae play a critical role in coastal ecosystems, but rising sea temperatures pose a significant threat to their survival. This study aims to investigate the thermal sensitivity of the three marine macroalgal species Padina boryana, Halimeda opuntia, and H. macroloba. Photosynthetic performance, metabolism, pigment content, and oxidative stress–related parameters were measured at temperatures of 28°C, 32°C, 36°C, and 40°C and the thermal performance curves (TPCs) were determined for Fv/Fm, Fv/F0, ϕPSII, and oxygen production to assess maximum rate (Rmax), optimum temperature (Topt), critical thermal maximum (CTmax), and thermal safety margin (TSM) of these three macroalgal species. The results showed that 40°C had the most negative effect on all three species with P. boryana demonstrating better performance compared to both Halimeda species. TPCs from photosynthetic performance revealed thermal sensitivity variations by species and P. boryana exhibited a broader thermal tolerance range compared to Halimeda. On the other hand, TPCs of oxygen production provided similar CTmax values. Based on TPC projections, all three species might survive future ocean warming and marine heatwaves, though these conditions will have significant effects, with P. boryana showing greater tolerance than both Halimeda species. This study highlights the differential thermal responses and sensitivities of these macroalgae, contributing to understanding their potential resiliencies under future climate change scenarios.

Over the last four decades, a broad stream of experimental literature has been published using the Common Pool Resource (CPR) game to study how people react to congestible resources, and how to keep such resources from socially harmful overexploitation. With the goal of providing guidance to future work on this still-important paradigm, we provide a narrative review of the literature, summarizing the results for several key aspects of the experimental operationalization. We classify these aspects into two broad categories. The first describes ‘environmental’ assumptions on the modeled resource problem itself. This refers to aspects of the experimental environment reflecting factors such as group size, resource size and asymmetry of access, which generally constitute the nature of the dilemma. The second category involves ‘institutional’ issues related to how people might solve the problem, such as user communication between subjects, information about previous subjects’ choices, and regulatory measures.

This essay proposes a novel framework for conceptualising climate politics through the lens of maritime custom. Drawing on A. W. Brian Simpson’s study of Regina vs Dudley and Stephens (1884) and Cătălin Avramescu’s intellectual history of cannibalism, it critically examines ‘providential’ and ‘catastrophic’ lifeboat metaphors in political thought. Despite their apparent opposition, these metaphors share common assumptions rooted in natural law traditions. As an alternative, the essay introduces the concept of the ‘commonist lifeboat’, grounded in maritime custom, class consciousness and environmental encounters. Inspired by historical practices of survival and mutual aid at sea, this approach suggests principles for addressing climate adaptation through bottom-up customs rather than top-down theoretical solutions. Three brief illustrations address climate policy’s intersections with property law, criminal law and international human rights law. This approach ultimately offers a historically informed perspective on climate crisis challenges, reconciling consequentialist arguments with concerns for dignity and consent.

We estimate the effect of temperature on the economic activity of Mexico utilizing 42 years of quarterly panel data of economic growth at the state level. Our findings elicit a concave relationship between economic growth and temperature that is maximized at around 20°C. Temperatures below or above this level are associated with lower growth rates. Temperature affects aggregate economic activity mainly through the effect it has on the growth of the primary and secondary sectors. In addition, the estimated sensitivity of economic growth to temperature has not decreased within our sample period which indicates that adaptation to climate change has been limited. When combining our panel estimates with temperature projections by the year 2100, our results suggest that quarterly economic growth might be reduced by 0.4 percentage points, on average, under an intermediate scenario of climate change with reductions as large as 1.0 percentage point during the spring and summer quarters.

The dominant understandings of space that inform International Relations (IR) theories struggle to account for the material dynamism of the natural environment. From neo-realism through to constructivism and post-structuralist IR perspectives, the natural environment is relegated to the background of analysis as the seemingly stable backdrop against which humans do global politics. Supporting this relegation is an associated tendency among IR theorists to view nature abstractly, rather than materially, in alignment with the cartographic imagination. Meanwhile, realist scholars adhering to the tenets of classical geopolitics foreground the natural environment as a factor in global politics yet view it as ontologically static and materially deterministic in its effects. In an era of unprecedented spatial flux amid human-induced climate change, this article seeks to contribute to ongoing efforts in IR and political geography to develop alternative spatial frameworks that can account for the natural environment’s material dynamism and instability. To do so, the article adopts a post-humanist framework that centres matter’s ontological fluidity and mobility. By affording primacy to matter-in-motion, it is argued, a richer understanding of space as performatively produced through relational processes can be developed, where attention is attuned not only to what matter ‘does’, but also how it moves.

The changing climate, land use, and agronomic practices are driving shifts in weed biology and management across Australia’s grain production systems. A stakeholder survey was conducted to identify key weed species, adaptations, and factors influencing future research priorities in three major cropping regions. The most problematic and adaptive species included rigid ryegrass (Lolium rigidum Gaud.), hairy fleabane (Erigeron bonariensis L.), Bromus spp. (includes both Bromus diandrus Roth and Bromus rigidus Roth), annual sowthistle (Sonchus oleraceus L.), wild radish (Raphanus raphanistrum L.), and feather fingergrass (Chloris virgata Sw.). These weeds also ranked high for future research focus. Observed adaptive traits included changes in dormancy, emergence patterns, shifts in phenology, and a shift towards year-round growth driven by warmer winters and increased summer rainfall. Regional responses varied slightly, with soil and crop management practices ranked as the primary driver of changing weed biology (88%), followed by climatic factors (56%), while soil factors (13%) were not considered as significant. Participants in the Northern region highlighted climate change (67%) as a major driver, while those in the Western region emphasized management practices (95%) and soil-related factors (32%). Sixty percent of participants noted that climatic changes were introducing new weeds, and 69% believed that changing weed biology was reducing control efficacy. National research priorities included understanding weed emergence dynamics (73%), effects of climate on herbicide efficacy (71%), and better understanding of weed ecology (68%). These findings highlight the trends and need for future research on changing weed biology and adaptive management strategies. Surveys of agronomists, farm advisors, researchers, and farmers provide a cost-effective method to monitor new weed adaptations. Refining survey methodologies and enhancing field data collection could improve the ability to track and manage weed adaptations to shifts in climate and management practices.

How do the effects of climate regulation on businesses impact public attitudes toward climate policy? While emissions intensity is the primary frame for understanding the effects of climate policy on business, theoretical scholarship and public discourse often emphasize that large firms will adjust to climate regulations easily while smaller firms will struggle. Because small businesses are sympathetic and large firms are unpopular, individuals who view climate regulation’s effects in line with this firm size account should be less likely to support climate change mitigation. To test this theory, we conduct an original survey of climate policy beliefs and then a survey experiment. We find evidence that distaste for large corporations increases opposition to climate action among people exposed to the idea that big companies can more easily navigate climate regulations than small companies. This work contributes to the literature on moral political economy and on the enduring difficulty of enacting effective climate change regulation within the United States.

The last half of the previous century has seen an explosion in publications on biocrusts, communities of eukaryotic and prokaryotic organisms inhabiting the uppermost surface of predominantly dryland soils. Much of the early work emanated from the western United States, yet there have been few attempts to document the breadth of this work and its contribution to our understanding of the ecosystem roles of biocrusts. We used a structured literature search to extract the 868 publications on biocrusts published between January 1900 and July 2024, and explored the trends in publications in 12 subject areas over that time. We found that almost half of the 868 publications focussed on the ecological and physiological effects of biocrusts and that more recent research explored emerging fields such as restoration, monitoring and climate change impacts. Five authors comprised about 10% of all authors on these publications, and 5.5% of publications had 10 or more authors. The number of authors per publication tended to increase over time. We identified three main periods of research ranging from basic ecology and exploration of ecological mechanisms pre-2000 to biocrust function, physiology and climatic drivers up to 2020. The post-2020 period was characterized by a greater emphasis on molecular approaches, restoration and climate change impacts. Our literature review identifies knowledge gaps associated with the need for more trained taxonomists, and greater education on biocrust ecology and function. Potential developments in biocrust research include a greater use and recognition of biocrust species traits, the establishment of a dedicated international biocrust society, and the development of a global research and monitoring network to coordinate methods and provide a framework to answer critical knowledge gaps.

The aim of this paper is to analyse the role of climate change on state fragility in sub-Saharan Africa (SSA). To do this, we estimate a country-time fixed effects panel data model using the two-way fixed effects estimator over the period 1995 to 2020 for 45 SSA countries. Our results show that climate change increases fragility in SSA; specifically, rising temperatures and decreasing rainfall increase the social, economic, political and security fragility of SSA countries. The study also reveals that gross domestic product, population growth, migrant remittances, foreign direct investment, natural resources, inflation and agricultural price volatility are mechanisms through which climate change exacerbates state fragility. Based on these results, we recommend climate change adaptation measures such as increasing water storage to cope with periods of extreme drought, growing climate-smart crops, and the introduction of environmental public policies.

Climate change has been shown to affect different aspects of society, with agriculture and the food system taking the highest hit. Several initiatives have been put in place to dampen such effects. Climate education could play an important role in the fight against climate change. Climate education ensures that farmers understand the anthropogenic causes of climate change and the principles underlying adaptation measures, hence informing adoption of sound adaptation measures. Although such theoretical underpinnings are clear, empirical evidence is lacking. We employ a multivariate probit model to empirically investigate the role of climate education in adoption of climate adaptation practices using data from Cameroon, whose humid tropical agroecology and forests are crucial to climate change mitigation in the Congo basin. Employing a linear model, we similarly evaluate the role of climate education on farm incomes as well as the role of perception of climate change. Our results show that climate education influences adoption of adaptation measures, especially simple and cost-effective measures. However, climate education does not affect farm income, neither does farmers’ perception of climate change. These results suggest that indigenous farmers may be more willing to choose a simple low-cost adaptation measure. The generated results are crucial for influencing climate change policy related to awareness building, education, and training for optimal adaptation efforts.