Cocoa production is highly variable and shows low yields globally, but the drivers of this variation are poorly understood. Climate has been proposed as one of the main drivers, but within-tree competition for resources and disease may also influence the number of cocoa pods produced. In addition, the relative importance of climate and within-tree competition for resources remains unknown. We evaluated the effects of climate, within-tree competition, and disease on cocoa pod dynamics in Ghana and assessed the relative importance of climate and within-tree competition. We monitored cocoa pod dynamics during three years for 1472 trees at 96 farms across Ghana. Counts of pods of different sizes were carried out every six weeks. Climate effects were evaluated based on monthly precipitation and temperature, including lag effects. Effects of within-tree resource competition on pod production were tested by assessing the effect of the number of larger-sized pods on a cocoa tree on the number of pods in smaller size classes using generalised linear mixed-effects models accounting for zero inflation. We consistently found that climate was a stronger driver of pod production than within-tree competition. Across size classes, the climatic conditions experienced at the time of fruit set had the strongest effect on the number of pods. For most pod size classes, both higher temperature and, unexpectedly, higher precipitation negatively influenced pod number. A larger number of large and mature pods negatively affected the number of cherelles (smallest pods), indicating within-tree competition among pods. This suggests that cocoa trees prioritise sustaining pods in larger sizes over producing new ones, for instance, through mechanisms like cherelle wilt. Our results suggest that higher precipitation increased the incidence of fungal diseases and indirectly reduced the number of pods produced. Thus, a combination of lagged climate effects and within-tree competition and disease drives the dynamics and development of pods on cocoa trees. Our results show that lagged climate effects should be considered for adaptation measures to climatic conditions (and climate change) and for determining the best timing for disease management interventions. These results help in understanding cocoa production dynamics and are important for yield and disease modelling.

Indicators of environmental impact can be used to inform the production, promotion and consumption of sustainable diets. Most environmental impacts associated with food production occur on farm; thus sustainable diets are reliant on sustainable agricultural practices. In this paper we review the current use of environmental indicators and metrics from global to local scales and highlight the need for locally relevant definitions to inform sustainable diets. Using Australia as a case study, we show that the diversity of food production systems is accompanied by a diversity of environmental issues, including climate change, land scarcity, nutrient pollution, water scarcity and biodiversity loss, each uniquely affecting different systems. However, while global datasets and indicators provide a consistent basis for estimating impacts and enabling country and food product comparisons, they often fail to capture the nuances of food production at national and sub-national scales. For example, land use may be a poor indicator of biodiversity loss when grazing a natural, low input rangeland. Similarly, water use is only relevant where there is competition for the resource, and eutrophication only where there is an adjacent water system to pollute. Thus, reporting frameworks used to inform sustainable diets need to be based on indicators that consider the context of local systems to demonstrate the clear linkage and how specific farming systems can drive sustainable diets. The development of provenance and traceability systems mean the tools are already available to track impacts at a regional, or even individual farm, level.

Landscape evolution in karst terrains affects both subterranean and surface settings. For better understanding of controlling processes and connections between the two, multiple geochronometers were used to date sediments and speleothems in upper-level passages of Fitton Cave adjacent to the Buffalo River, northern Arkansas, within the southern Ozark Plateau. Burial cosmogenic-nuclide dating of coarse sediments indicates that gravel pulses washed into upper passages at 2.2 Ma and 1.25 Ma. These represent the oldest epigenetic cave deposits documented in this region. Associated sands and clay-rich sediments mostly have reversed magnetic polarity and thermally transferred optically stimulated luminescence dates of 1.2 to 1.0 Ma. Abandonment of these upper passages began before 0.72 Ma, when coarse sediment was deposited in a passage incised below older sediment. Maximum U-series dates of 0.7–0.4 Ma for flowstones capping clastic deposits mark the stabilization of older sediments and a change to vadose conditions that allowed post–0.4 Ma stalagmite growth. Resulting valley incision rates since 0.85 Ma are estimated at 27 m/Ma. Coarse cave-sediment pulses correlate to Laurentide glacial tills about 300 km to the north, suggesting climate influence on periglacial sediment production. Dated cave sediments also may correlate with undated older strath terraces preserved at similar heights above the Buffalo River.

This article is an introduction and guide to investigating past relationships between climate and human behavior. Improving understanding of these relationships is essential as humanity confronts the challenges of our warming world. However, how to investigate potential climatic influences on human behavior in the past is rarely presented or discussed as a distinct mode of inquiry. This article aims to fill this gap by providing a practical tool kit for students, archaeologists, anthropologists, and other historically focused social scientists. It is structured as a series of seven key steps to creating a research design for a climate and human behavior study, from identifying research questions to presenting results. Most of the conceptual models, methods, data, and examples provided have worldwide relevance and are informed by the long history of climate and human behavior studies in the North American Southwest. By expanding competence in this domain, we can enrich documentation and interpretations of the past and insights will emerge that will contribute to preparing for and responding to our warming world.

This article investigates the global history of dryland modernisation through the case study of southern Italy. From the early twentieth century to the fascist years, several intellectuals, scientists, and politicians reinterpreted the apparent and long-standing backwardness of this region as fundamentally due to its hydrology and climate: southern Italy was rediscovered as a dry land, formally part of Italy and civilised Europe and yet environmentally closer to extra-European spaces of empire. The article shows how Italian agrarian scientists mobilised this ‘environmental Otherness’ of the Italian south as the key to developing a ‘dryland’ science alternative to that of ‘humid’ northern Italy and continental Europe. Instead, this ‘dryland’ approach to modernisation grounded southern Italy within a vast transimperial network defined by the co-production and circulation of knowledge and technologies allowing the adaptation of modern and intensive food production to semi-arid regions. As such, the article argues that Italian agrarian scientists redefined the spatial order of the Italian south in a transimperial sense, embracing its environmental Otherness as a vantage point for its rehabilitation within Italy’s nation-building.

Between 2022 and 2024, Somalia’s ongoing drought claimed more than 70 000 lives, with nearly 40% of these deaths among children under 5. This tragic loss highlights the urgent need for action to address the disproportionate impact of the drought on Somalia’s most vulnerable populations. The 2022 drought, which affected nearly half of the country’s population, brought Somalia to the brink of famine, leaving many families without essential resources and health care, particularly in the southern-central regions like Banadir, Bay, and Lower Shabelle. Despite narrowly avoiding famine through the efforts of the Somali government and international partners, the consequences of the drought continue to devastate communities. The study “From Insight to Action: An Update on Mortality Patterns in Somalia” reveals that most excess deaths were children, presenting not only a tragedy for families but also a long-term social and economic setback for the nation. WHO and UNICEF stress the need for a long-term approach to address Somalia’s vulnerabilities, emphasizing the importance of building resilient health systems, investing in climate-resilient agriculture, and empowering communities. The international community must also commit to supporting Somalia’s development to break the cycle of disaster and ensure a brighter future for the nation’s children.

In many areas of The Gambia, West Africa, population crowding in a degraded environment has forced close interactions of diurnal primate species with humans. We assessed intestinal parasitic infection prevalence and diversity in 4 diurnal non-human primate (NHP) species, Chlorocebus sabaeus, Erythrocebus patas, Papio papio and Piliocolobus badius across 13 sampling sites. The effect of human activity, determined by the human activity index, and NHP group size on parasite richness was assessed using a generalized linear mixed model (GLMM). The most common protozoa identified were Entamoeba coli (30%) and Iodamoeba buetschlii (25%). The most common helminths were Strongyloides fuelleborni (11%), Oesophagostomum spp. (9%) and Trichuris trichiura (9%). Two of six (6%) Cyclospora spp. infections detected sequenced as Cyclospora cercopitheci (both in C. sabaeus). The more arboreal P. badius trended towards a lower prevalence of intestinal parasites, although this was not statistically significant (χ2 P = 0.105). Human activity or group size did not have any significant effect on parasite richness for P. badius (P = 0.161 and P = 0.603) or P. papio (P = 0.817 and P = 0.607, respectively). There were insufficient observations to fit a GLMM to E. patas or C. sabaeus. Our reports present the richness and diversity of intestinal parasites in 4 diurnal NHPs in The Gambia, West Africa. Despite desertification and habitat loss, our results indicate that the prevalence and diversity of intestinal parasites in Gambian NHPs are seemingly unaffected by human activity. Further investigation with a larger dataset is required to better elucidate these findings.

What is climate history? How can it serve as a lens through which to view other historical questions? This roundtable identifies key themes in Gilded Age and Progressive Era climate history, and demonstrates that this era was pivotal for both scientific and cultural perceptions of climate. It also shows how climate history can illuminate other subjects, including histories of science, medicine, health, and race. Further, it considers present-day implications. This roundtable began as a session sponsored by the Society for Historians of the Gilded Age and Progressive Era at the 2024 Organization of American Historians annual meeting in New Orleans. What follows is a conversation based on that panel, a selected bibliography of scholarly sources, and a collection of primary sources for teaching climate history.

Changing sea-ice conditions have significant societal impacts and implications across Alaska and the Arctic. This research examined the relationship between sea ice and extreme weather events with socio-economic impacts in Nome, Alaska (1990–2020), a community that has experienced notable changes in sea ice and impacts from extreme weather events. The research is based on the analysis of sea-ice concentrations from passive microwave data, socio-economic impacts of extreme weather events from an archival analysis of newspaper coverage, and an examination of the relationship between sea-ice concentrations and impacts. We found that sea-ice concentrations at the time of the reported socio-economic impacts were all characterised by ice-free conditions. Additionally, extreme events linked to socio-economic impacts occurred when sea-ice concentrations were at or below their historical (1979–2000) median for the day. Key implications for the observed increased probability of ice-free conditions in the autumn include a greater likelihood that a given coastal storm from November to mid-December may contribute to socio-economic impacts, which may have been mitigated by sea ice in the past, as well as an increased potential for impacts to occur when they have previously not been experienced.

This research examines whether high temperatures and exposure to childhood rainfall and heat shocks are a cognitive drag on children in Uganda. First, it asks whether students perform worse on a test on hotter days. Second, it examines whether previous longer-term exposure to high temperatures and unusual rainfall influences current test scores and educational outcomes. The analysis shows that high temperatures on test dates harm test performance, especially for girls and children younger than ten, implying additional temperature control considerations for particular demographics. The analysis of childhood climate shocks, which employs within-parish distributions of rainfall and heat, shows that children who experience rain or heat above the $80^{th}$ percentile of the parish distribution from birth until age 4 have worse learning outcomes in math, English, or local language literacy.

While malnutrition (including both undernutrition and overweight/obesity and related non-communicable diseases) remains a persistent challenge in countries around the world, it is far from alone as a threat to human development and wellbeing – and is increasingly viewed as intersecting with climate change and environmental degradation. At the crossroads of these issues, animal-source foods (ASFs, including meat, fish, seafood, dairy and eggs) have attracted considerable attention in recent years, both for their role in diets and for their environmental impacts. Heated debate has focused on the potential benefits of reducing consumption of ASFs as well as the potential nutritional risks associated with this. ASF production also plays an important role in livelihoods, particularly in low- and middle-income countries. ASFs are also central to many food cultures and traditions, highly valued by many consumers. As the issues associated with ASFs are intertwined, they must be considered jointly and with nuance. Given wide global ranges in ASF consumption, environmental footprints and malnutrition rates and types, considering equity (in terms of ASF consumption and production) is also critical. This review examines these complex issues, discussing ASFs from the perspectives of nutrition and health, environmental impacts, livelihoods and society, and equity. It also examines potential future options for reducing environmental impacts of ASFs.