Climate change and nephrology.

Climate change should be of special concern for the nephrologist, as the kidney has a critical role in protecting the host from dehydration, but it is also a favorite target of heat stress and dehydration. Here we discuss how rising temperatures and extreme heat events may affect the kidney. The most severe presentation of heat stress is heat stroke, which can result in severe electrolyte disturbance and both acute and chronic kidney disease (CKD). However, lesser levels of heat stress also have multiple effects, including exacerbating kidney disease and precipitating cardiovascular events in subjects with established kidney disease. Heat stress can also increase the risk for kidney stones, cause multiple electrolyte abnormalities and induce both acute and chronic kidney disease. Recently there have been multiple epidemics of CKD of uncertain etiology in various regions of the world, including Mesoamerica, Sri Lanka, India and Thailand. There is increasing evidence that climate change and heat stress may play a contributory role in these conditions, although other causes, including toxins, could also be involved. As climate change worsens, the nephrologist should prepare for an increase in diseases associated with heat stress and dehydration.

Mortality in Puerto Rico after Hurricane Maria.

BACKGROUND: Quantifying the effect of natural disasters on society is critical for recovery of public health services and infrastructure. The death toll can be difficult to assess in the aftermath of a major disaster. In September 2017, Hurricane Maria caused massive infrastructural damage to Puerto Rico, but its effect on mortality remains contentious. The official death count is 64. METHODS: Using a representative, stratified sample, we surveyed 3299 randomly chosen households across Puerto Rico to produce an independent estimate of all-cause mortality after the hurricane. Respondents were asked about displacement, infrastructure loss, and causes of death. We calculated excess deaths by comparing our estimated post-hurricane mortality rate with official rates for the same period in 2016. RESULTS: From the survey data, we estimated a mortality rate of 14.3 deaths (95% confidence interval [CI], 9.8 to 18.9) per 1000 persons from September 20 through December 31, 2017. This rate yielded a total of 4645 excess deaths during this period (95% CI, 793 to 8498), equivalent to a 62% increase in the mortality rate as compared with the same period in 2016. However, this number is likely to be an underestimate because of survivor bias. The mortality rate remained high through the end of December 2017, and one third of the deaths were attributed to delayed or interrupted health care. Hurricane-related migration was substantial. CONCLUSIONS: This household-based survey suggests that the number of excess deaths related to Hurricane Maria in Puerto Rico is more than 70 times the official estimate. (Funded by the Harvard T.H. Chan School of Public Health and others.).

The Climate-Smart Emergency Department: A Primer.

Climate change and environmental pollution from health care present urgent, complex challenges. The US health care sector produces 10% of total US greenhouse gas emissions, which have negative influences on human and environmental health. The emergency department (ED) is an important place in the hospital to become more environmentally responsible and "climate smart," a term referring to the combination of low-carbon and resilient health care strategies. Our intent is to educate and motivate emergency providers to action by providing a guide to sustainable health care and an approach to creating a climate-smart ED.

Clinical Implications of Climate Change on US Emergency Medicine: Challenges and Opportunities.

The adverse influences of climate change are manifesting as health burdens relevant to clinical practice, affecting the very underpinnings of health and stressing the health care system. Emergency medicine is likely to bear a large burden, with its focus on urgent and emergency care, through its role as a safety-net provider for vulnerable populations and as a leader in disaster medicine. Clinically, climate change is affecting emergency medicine practice through the amplification of climate-related disease patterns and epidemiologic shifts for conditions diagnosed and treated in emergency departments (EDs), especially for vulnerable populations. In addition, climate-driven intensification of extreme weather is disrupting health care delivery in EDs and health care systems. Thus, there are significant opportunities for emergency medicine to lead the medical response to climate change through 7 key areas: clinical practice improvements, building resilient EDs and health care systems, adaptation and public health engagement, disaster preparedness, mitigation, research, and education. In the face of this growing health threat, systemwide preparation rooted in local leadership and responsiveness is necessary to efficiently and effectively care for our vulnerable communities.

Increase of core temperature affected the progression of kidney injury by repeated heat stress exposure.

An epidemic of chronic kidney disease of unknown etiology (Mesoamerican nephropathy) has emerged in hot regions of Central America. We have demonstrated that dehydration associated with recurrent heat exposure causes chronic kidney disease in animal models. However, the independent influence of core body temperature on kidney injury has not been explored. In the present study, we tested the hypothesis that kidney injury could be accelerated by increasing body temperature independent of external temperature. Wild-type mice were exposed to heat (39.5°C, 30 min, 2 times daily) with or without the mitochondrial uncoupling agent 2,4-dinitrophenol (DNP) for 10 days. Core temperature, renal function, proteinuria, and renal histological and biochemical analyses were performed. Isolated mitochondria markers of oxidative stress were evaluated from kidney tissue. DNP increased body core temperature in response to heat by 1°C (42 vs. 41°C), which was transient. The mild increase in temperature correlated with worsening albuminuria (R = 0.715, P < 001), renal tubular injury, and interstitial infiltration of monocytes/macrophages. Tubular injury was marked in the outer medulla. This was associated with a reduction in kidney tissue ATP levels (nonheated control: 16.71 ± 1.33 nmol/mg and DNP + heat: 13.08 ± 1.12 nmol/mg, P < 0.01), reduced mitochondria, and evidence for mitochondrial oxidative stress. The results of the present study suggest that kidney injury in heat stress is markedly worsened by increasing core temperature. This is consistent with the hypothesis that clinical and subclinical heat stroke may play a role in Mesoamerican nephropathy.

Evaluation of heat stress and cumulative incidence of acute kidney injury in sugarcane workers in Guatemala.

OBJECTIVE: Agricultural workers worldwide exposed to heat stress could be at the risk of kidney injury, which could lead to chronic kidney disease of an unknown origin (CKDu). Hydration has been promoted as a key measure to reduce kidney injury. In the presence of a hydration intervention, the incidence of acute kidney injury (AKI) was calculated in a sugarcane worker population in Guatemala and several risk factors were evaluated. METHODS: We measured kidney function at the beginning and end of the work shift at three time points in 517 sugarcane workers. We defined AKI as an increase in serum creatinine of 26.5 µmol/L or 50% or more from the pre-shift value. Associations between AKI and risk factors were examined, including interactions with hydration status. RESULTS: The prevalence of dehydration post-shift (> 1.020 specific gravity) was 11% in February, 9% in March, and 6% in April. Cumulative incidence of AKI was 53% in February, 54% in March, and 51% in April. AKI was associated with increasing post-shift specific gravity, a dehydration marker, (OR 1.24, 95% CI 1.02-1.52) and with lower electrolyte solution intake (OR 0.94, 95% CI 0.89-0.99). CONCLUSIONS: Dehydration and insufficient electrolyte consumption are risk factors for AKI. However even well-hydrated sugarcane workers routinely experience AKI. While hydration is important and protective, there is a need to understand other contributors to risk of AKI and identify prevention strategies with these workers.

Experimental heat stress nephropathy and liver injury are improved by allopurinol.

An epidemic of chronic kidney disease (CKD) has been observed in Central America among workers in the sugarcane fields. One hypothesis is that the CKD may be caused by recurrent heat stress and dehydration, and potentially by hyperuricemia. Accordingly, we developed a murine model of kidney injury associated with recurrent heat stress. In the current experiment, we tested whether treatment with allopurinol (a xanthine oxidase inhibitor that reduces serum urate) provides renal protection against recurrent heat stress and dehydration. Eight-week-old male C57BL/6 mice were subjected to recurrent heat stress (39.5°C for 30 min, 7 times daily, for 5 wk) with or without allopurinol treatment and were compared with control animals with or without allopurinol treatment. Mice were allowed ad libitum access to normal laboratory chow (Harlan Teklad). Kidney histology, liver histology, and renal function were examined. Heat stress conferred both kidney and liver injury. Kidneys showed loss of proximal tubules, infiltration of monocyte/macrophages, and interstitial collagen deposition, while livers of heat-stressed mice displayed an increase in macrophages, collagen deposition, and myofibroblasts. Allopurinol provided significant protection and improved renal function in the heat-stressed mice. The renal protection was associated with reduction in intrarenal uric acid concentration and heat shock protein 70 expression. Heat stress-induced renal and liver injury can be protected with allopurinol treatment. We recommend a clinical trial of allopurinol for individuals developing renal injury in rural areas of Central America where the epidemic of chronic kidney disease is occurring.

Climate change and women's health: Impacts and policy directions.

In a Policy Forum, Cecilia Sorensen and colleagues discuss the implications of climate change for women's health.

Defining Roles and Responsibilities of the Health Workforce to Respond to the Climate Crisis.

Importance: The adverse effects of climate change are now apparent, disproportionately affecting marginalized and vulnerable populations and resulting in urgent worldwide calls to action. Health professionals occupy a critical position in the response to climate change, including in climate mitigation and adaptation, and their professional expertise and roles as health messengers are currently underused in the society-wide response to this crisis. Observations: Clinical and public health professionals have important roles and responsibilities, some of which are shared, that they must fill for society to successfully mitigate the root causes of climate change and build a health system that can reduce morbidity and mortality impacts from climate-related hazards. When viewed through a preventive framework, the unique and synergizing roles and responsibilities provide a blueprint for investment in climate change-related prevention (primary, secondary, and tertiary), capacity building, education, and training of the health workforce. Substantial investment in increasing the competence and collaboration of health professionals is required, which must be undertaken in an urgent, coordinated, and deliberate manner. Conclusions and Relevance: Exceptional collaboration, knowledge sharing, and workforce capacity building are essential to tackle the complex ways in which climate change threatens health. This framework serves as a guide for health system leaders, education institutions, policy planners, and others seeking to create a more resilient and just health system.

The 2023 Latin America report of the Lancet Countdown on health and climate change: the imperative for health-centred climate-resilient development.

In 2023, a series of climatological and political events unfolded, partly driving forward the global climate and health agenda while simultaneously exposing important disparities and vulnerabilities to climate-related events. On the policy front, a significant step forward was marked by the inaugural Health Day at COP28, acknowledging the profound impacts of climate change on health. However, the first-ever Global Stocktake showed an important gap between the current progress and the targets outlined in the Paris Agreement, underscoring the urgent need for further and decisive action. From a Latin American perspective, some questions arise: How do we achieve the change that is needed? How to address the vulnerabilities to climate change in a region with long-standing social inequities? How do we promote intersectoral collaboration to face a complex problem such as climate change? The debate is still ongoing, and in many instances, it is just starting. The renamed regional centre Lancet Countdown Latin America (previously named Lancet Countdown South America) expanded its geographical scope adding Mexico and five Central American countries: Costa Rica, El Salvador, Guatemala, Honduras, and Panama, as a response to the need for stronger collaboration in a region with significant social disparities, including research capacities and funding. The centre is an independent and multidisciplinary collaboration that tracks the links between health and climate change in Latin America, following the global Lancet Countdown's methodologies and five domains. The Lancet Countdown Latin America work hinges on the commitment of 23 regional academic institutions, United Nations agencies, and 34 researchers who generously contribute their time and expertise. Building from the first report, the 2023 report of the Lancet Countdown Latin America, presents 34 indicators that track the relationship between health and climate change up to 2022, aiming at providing evidence to public decision-making with the purpose of improving the health and wellbeing of Latin American populations and reducing social inequities through climate actions focusing on health. This report shows that Latin American populations continue to observe a growing exposure to changing climatic conditions. A warming trend has been observed across all countries in Latin America, with severe direct impacts. In 2022, people were exposed to ambient temperatures, on average, 0.38 °C higher than in 1986-2005, with Paraguay experiencing the highest anomaly (+1.9 °C), followed by Argentina (+1.2 °C) and Uruguay (+0.9 °C) (indicator 1.1.1). In 2013-2022, infants were exposed to 248% more heatwave days and people over 65 years old were exposed to 271% more heatwave days than in 1986-2005 (indicator 1.1.2). Also, compared to 1991-2000, in 2013-2022, there were 256 and 189 additional annual hours per person, during which ambient heat posed at least moderate and high risk of heat stress during light outdoor physical activity in Latin America, respectively (indicator 1.1.3). Finally, the region had a 140% increase in heat-related mortality from 2000-2009 to 2013-2022 (indicator 1.1.4). Changes in ecosystems have led to an increased risk of wildfires, exposing individuals to very or extremely high fire danger for more extended periods (indicator 1.2.1). Additionally, the transmission potential for dengue by Aedes aegypti mosquitoes has risen by 54% from 1951-1960 to 2013-2022 (indicator 1.3), which aligns with the recent outbreaks and increasing dengue cases observed across Latin America in recent months. Based on the 2023 report of the Lancet Countdown Latin America, there are three key messages that Latin America needs to further explore and advance for a health-centred climate-resilient development. Latin American countries require intersectoral public policies that simultaneously increase climate resilience, reduce social inequities, improve population health, and reduce greenhouse gas (GHG) emissions. The findings show that adaptation policies in Latin America remain weak, with a pressing need for robust vulnerability and adaptation (V&A) assessments to address climate risks effectively. Unfortunately, such assessments are scarce. Up to 2021, Brazil is the only country that has completed and officially reported a V&A to the 2021 Global Survey conducted by the World Health Organization (WHO). Argentina, Guatemala, and Panama have also conducted them, but they have not been reported (indicator 2.1.1). Similarly, efforts in developing and implementing Health National Adaptation Plans (HNAPs) are varied and limited in scope. Brazil, Chile, and Uruguay are the only countries that have an HNAP (indicator 2.1.2). Moreover, self-reported city-level climate change risk assessments are very limited in the region (indicator 2.1.3). The collaboration between meteorological and health sectors remains insufficient, with only Argentina, Brazil, Colombia, and Guatemala self-reporting some level of integration (indicator 2.2.1), hindering comprehensive responses to climate-related health risks in the region. Additionally, despite the urgent need for action, there has been minimal progress in increasing urban greenspaces across the region since 2015, with only Colombia, Nicaragua, and Venezuela showing slight improvements (indicator 2.2.2). Compounding these challenges is the decrease in funding for climate change adaptation projects in Latin America, as evidenced by the 16% drop in funds allocated by the Green Climate Fund (GCF) in 2022 compared to 2021. Alarmingly, none of the funds approved in 2022 were directed toward climate change and health projects, highlighting a critical gap in addressing health-related climate risks (indicator 2.2.3). From a vulnerability perspective, the Mosquito Risk Index (MoRI) indicates an overall decrease in severe mosquito-borne disease risk in the region due to improvements in water, sanitation, and hygiene (WASH) (indicator 2.3.1). Brazil and Paraguay were the only countries that showed an increase in this indicator. It is worth noting that significant temporal variation within and between countries still persists, suggesting inadequate preparedness for climate-related changes. Overall, population health is not solely determined by the health sector, nor are climate policies a sole responsibility of the environmental sector. More and stronger intersectoral collaboration is needed to pave development pathways that consider solid adaptation to climate change, greater reductions of GHG emissions, and that increase social equity and population health. These policies involve sectors such as finance, transport, energy, housing, health, and agriculture, requiring institutional structures and policy instruments that allow long-term intersectoral collaboration. Latin American countries need to accelerate an energy transition that prioritises people's health and wellbeing, reduces energy poverty and air pollution, and maximises health and economic gains. In Latin America, there is a notable disparity in energy transition, with electricity generation from coal increasing by an average of 2.6% from 1991-2000 to 2011-2020, posing a challenge to efforts aimed at phasing out coal (indicator 3.1.1). However, this percentage increase is conservative as it may not include all the fossil fuels for thermoelectric electricity generation, especially during climate-related events and when hydropower is affected (Panel 4). Yet, renewable energy sources have been growing, increasing by an average of 5.7% during the same period. Access to clean fuels for cooking remains a concern, with 46.3% of the rural population in Central America and 23.3% in South America lacking access to clean fuels in 2022 (indicator 3.1.2). It is crucial to highlight the concerning overreliance on fossil fuels, particularly liquefied petroleum gas (LPG), as a primary cooking fuel. A significant majority of Latin American populations, approximately 74.6%, rely on LPG for cooking. Transitioning to cleaner heating and cooking alternatives could also have a health benefit by reducing household air pollution-related mortality. Fossil fuels continue to dominate road transport energy in Latin America, accounting for 96%, although some South American countries are increasing the use of biofuels (indicator 3.1.3). Premature mortality attributable to fossil-fuel-derived PM2.5 has shown varied trends across countries, increasing by 3.9% from 2005 to 2020 across Latin America, which corresponds to 123.5 premature deaths per million people (indicator 3.2.1). The Latin American countries with the highest premature mortality rate attributable to PM2.5 in 2020 were Chile, Peru, Brazil, Colombia, Mexico, and Paraguay. Of the total premature deaths attributable to PM2.5 in 2020, 19.1% was from transport, 12.3% from households, 11.6% from industry, and 11% from agriculture. From emission and capture of GHG perspective, commodity-driven deforestation and expansion of agricultural land remain major contributors to tree cover loss in the region, accounting for around 80% of the total loss (indicator 3.3). Additionally, animal-based food production in Latin America contributes 85% to agricultural CO2 equivalent emissions, with Argentina, Brazil, Panama, Paraguay, and Uruguay ranking highest in per capita emissions (indicator 3.4.1). From a health perspective, in 2020, approximately 870,000 deaths were associated with imbalanced diets, of which 155,000 (18%) were linked to high intake of red and processed meat and dairy products (indicator 3.4.2). Energy transition in Latin America is still in its infancy, and as a result, millions of people are currently exposed to dangerous levels of air pollution and energy poverty (i.e., lack of access to essential energy sources or services). As shown in this report, the levels of air pollution, outdoors and indoors, are a significant problem in the wholeregion, with marked disparities between urban and rural areas. In 2022, Peru, Chile, Mexico, Guatemala, Colombia, El Salvador, Brazil, Uruguay, Honduras, Panama, and Nicaragua were in the top 100 most polluted countries globally. Transitioning to cleaner sources of energy, phasing out fossil fuels, and promoting better energy efficiency in the industrial and housing sectors are not only climate mitigation measures but also huge health and economic opportunities for more prosperous and healthy societies. Latin American countries need to increase climate finance through permanent fiscal commitments and multilateral development banks to pave climate-resilient development pathways. Climate change poses significant economic costs, with investments in mitigation and adaptation measures progressing slowly. In 2022, economic losses due to weather-related extreme events in Latin America were US$15.6 billion -an amount mainly driven by floods and landslides in Brazil-representing 0.28% of Latin America's Gross Domestic Product (GDP) (indicator 4.1.1). In contrast to high-income countries, most of these losses lack insurance coverage, imposing a substantial financial strain on affected families and governments. Heat-related mortality among individuals aged 65 and older in Latin America reached alarming levels, with losses exceeding the equivalent of the average income of 451,000 people annually (indicator 4.1.2). Moreover, the total potential income loss due to heat-related labour capacity reduction amounted to 1.34% of regional GDP, disproportionately affecting the agriculture and construction sectors (indicator 4.1.3). Additionally, the economic toll of premature mortality from air pollution was substantial, equivalent to a significant portion of regional GDP (0.61%) (indicator 4.1.4). On a positive note, clean energy investments in the region increased in 2022, surpassing fossil fuel investments. However, in 2020, all countries reviewed continued to offer net-negative carbon prices, revealing fossil fuel subsidies totalling US$23 billion. Venezuela had the highest net subsidies relative to current health expenditure (123%), followed by Argentina (10.5%), Bolivia (10.3%), Ecuador (8.3%), and Chile (5.6%) (indicator 4.2.1). Fossil fuel-based energy is today more expensive than renewable energy. Fossil fuel burning drives climate change and damages the environment on which people depend, and air pollution derived from the burning of fossil fuels causes seven million premature deaths each year worldwide, along with a substantial burden of disease. Transitioning to sustainable, zero-emission energy sources, fostering healthier food systems, and expediting adaptation efforts promise not only environmental benefits but also significant economic gains. However, to implement mitigation and adaptation policies that also improve social wellbeing and prosperity, stronger and solid financial systems are needed. Climate finance in Latin American countries is scarce and strongly depends on political cycles, which threatens adequate responses to the current and future challenges. Progress on the climate agenda is lagging behind the urgent pace required. While engagement with the intersection of health and climate change is increasing, government involvement remains inadequate. Newspaper coverage of health and climate change has been on the rise, peaking in 2022, yet the proportion of climate change articles discussing health has declined over time (indicator 5.1). Although there has been significant growth in the number of scientific papers focusing on Latin America, it still represents less than 4% of global publications on the subject (indicator 5.3). And, while health was mentioned by most Latin American countries at the UN General Debate in 2022, only a few addressed the intersection of health and climate change, indicating a lack of awareness at the governmental level (indicator 5.4). The 2023 Lancet Countdown Latin America report underscores the cascading and compounding health impacts of anthropogenic climate change, marked by increased exposure to heatwaves, wildfires, and vector-borne diseases. Specifically, for Latin America, the report emphasises three critical messages: the urgent action to implement intersectoral public policies that enhance climate resilience across the region; the pressing need to prioritise an energy transition that focuses on health co-benefits and wellbeing, and lastly, that need for increasing climate finance by committing to sustained fiscal efforts and engaging with multilateral development banks. By understanding the problems, addressing the gaps, and taking decisive action, Latin America can navigate the challenges of climate change, fostering a more sustainable and resilient future for its population. Spanish and Portuguese translated versions of this Summary can be found in Appendix B and C, respectively. The full translated report in Spanish is available in Appendix D.

The impacts of climate migration on perinatal health and opportunities to safeguard perinatal well-being.

The disparate health consequences of climate change and migration have been separately explored, and the gendered impacts of climate change have been previously established. Nonetheless, there is limited research on the specific nexus of climate change-migration-sexual and reproductive health (SRH). This chapter reviews specific vulnerabilities faced by women and infants throughout the perinatal period, and how these are affected by climate change-induced migration in different migratory contexts. The available literature refers to antenatal and postnatal care utilization, access to water, sanitation, and hygiene facilities, childbirth and delivery challenges, and infant feeding barriers, amongst other concerns. The discussion explored in this chapter highlights the need to develop disaster frameworks that reflect the heterogeneity of outcomes related to specific and unique climate migration contexts.

Climate and health capacity building for health professionals in the Caribbean: A pilot course.

Climate change is a reality in the Caribbean and its effects are already harming health, yet the health workforce capacity to implement climate mitigation and adaptation measures is lacking. From March-May of 2022, a free, live-virtual, evidence and competency based 10-week climate and health course targeted toward health risks in the Caribbean was deployed to: (1) increase communication about climate and health, (2) equip health professionals with knowledge and skills that could be readily incorporated into practice, and (3) engage health professionals with climate and health initiatives within their communities. Participants in this course came from 37 countries, 10 different health-related fields, and five different general places of work. Longitudinal surveys revealed significant changes in health professional communication, engagement and application of climate and health knowledge and skills. Live-virtual, evidence and competency-based courses, regional-specific courses have the potential to change health professional behaviors toward addressing climate impacts on health.

Building capacity of healthcare professionals and community members to address climate and health threats in The Bahamas: Analysis of a green climate fund pilot workshop.

Climate change is a preeminent threat to health and health systems in The Bahamas. Climate and health resilience depends upon a knowledgeable and coordinated healthcare system and workforce that is highly connected and coordinated with a knowledgeable and empowered community. We present the methodology and results of a novel educational workshop, designed to increase the knowledge and awareness of health care professionals and community members with the goal of empowering them to engage in climate mitigation and adaptation strategies. Following the training, participants demonstrated increased knowledge of the causes of climate change, health exposures, climate-sensitive diseases, and vulnerable populations relevant to The Bahamas. Further, participants reported high levels of willingness and readiness to tackle climate change and its health consequences. Results from this workshop suggest that such a model may serve as a guide for building grass-roots resilience in communities worldwide.

Extramural US Federal Research Grants For Health Outcomes Associated With Climate Change Inadequate, Too Narrow In Focus.

Climate change causes and exacerbates disease, creates and worsens health disparities, disrupts health care delivery, and imposes a significant disease burden in the US and globally. Critical knowledge gaps hinder an evidence-based response and are perpetuated by scarce federal research funds. We identified and described extramural US federal research funding (that is, grants provided to organizations and institutions outside of federal agencies) that both addressed health outcomes associated with climate change and was awarded between 2010 and 2020. During this eleven-year period, 102 grants met our criteria, totaling approximately $58.7 million, or approximately $5.3 million per year (2020 adjusted US dollars). Federal investments in climate change and health research during this period failed to address the breadth of climate-sensitive exposures, health outcomes, and impacts on vulnerable populations. Moving forward, in addition to increasing investment in climate and health research across all known hazards, critical attention should be placed on vulnerable populations and health equity. To achieve this, increased federal research coordination and cooperation are needed, as well as a mechanism to track this funding.

Mechanisms underlying food insecurity in the aftermath of climate-related shocks: a systematic review.

Food insecurity is prevalent, affecting 1·2 billion people globally in 2021. However, the effects of food insecurity are unequally distributed across populations and climate-related shocks threaten to exacerbate food insecurity and associated health consequences. The mechanisms underlying this exacerbation at the household level are largely unknown. We aimed to synthesise the available evidence on the mechanisms connecting extreme climate events to household-level food insecurity and highlight the research gaps that must be addressed to inform better food security and health policy. For this systematic review, a comprehensive literature search was done by a medical librarian in February, 2021 for articles about food security and climate-related shocks. Relevant publications were identified by searching the following databases with a combination of standardised index terms and keywords: MEDLINE, Embase, CINAHL, GreenFILE, Environment Complete, Web of Science Core Collection, and Global Health. Searches were limited to human studies published in English. Included studies measured food security outcomes using indicators developed by the UN Food and Agricultural Organization (ie, consumption patterns, livelihood change, malnutrition, and mortality) and explained the mechanism behind the household-level or population-level food insecurity. Purely theoretical, modelling, and review studies were excluded. Quality assessment was conducted using the appropriate Joanna Briggs Institute Critical Appraisal Tool. Data were analysed using thematic analysis of the categories of mechanism (interpreted using internationally accepted frameworks), risk and resilience factors, and author policy recommendations. We found a paucity of data with only 18 studies meeting criteria for inclusion out of 337 studies identified for full-text review. All the studies that were included in our analysis showed worse food security outcomes after climate-related shocks. Food availability was the most common mechanism cited (17 studies), although most studies addressed at least one additional mechanism (15 studies). Studies were of mixed methodologies with nuanced discussions of risk and resilience factors, and of policy recommendations. This systematic review shows that there is an incomplete assessment of food security at the household and community level after climate-related shocks in the literature and finds that food availability is the primary mechanism studied. The low number of studies on this topic limits subgroup analysis and generalisability; however, the good quality of the studies allows for important policy recommendations around improving resilience to climate shocks and suggestions for future research including the need for a more granular understanding of mechanisms and feasible adaptation solutions.

Creating climate-informed physician leaders: The evolution of a physician fellowship in climate and health science policy.

Climate change poses numerous near and long-term challenges for our society, and the human health consequences are increasingly recognized as unprecedented. Responding to these health hazards requires a healthcare workforce composed of climate-informed clinicians. As trusted messengers, physicians play a vital role in informing and preparing the public for health impacts of climate change. We describe an evolving graduate medical education fellowship for physicians from all specialties capable of training leaders in this field. Our program pairs fellows with federal and non-governmental partners to provide expertise in climate policy and empower them to be change agents. The accelerating response to climate change from the federal government coupled with an increased recognition of the impacts of climate hazards on health demands a climate-informed clinical workforce. The expansion of this fellowship to accommodate trainees from multiple specialties and its innovative structure leveraging local and national partnerships sets a standard for how similar programs can be developed in addressing the greatest public health threat and opportunity of the century.

Climate change and COVID-19: Assessing the vulnerability and resilience of U.S. Indigenous communities to syndemic crises.

The rapid emergence of the COVID-19 pandemic and the insidiously evolving climate crisis represent two of the most pressing public health threats to Indigenous Peoples in the United States. Understanding the ways in which these syndemics uniquely impact Indigenous Peoples, given the existing health disparities for such communities, is essential if we are to address modifiable root causes of health vulnerability and devise effective and equitable strategies to protect and improve health in the evolving climate landscape. We explore the compounding burden of the COVID-19 pandemic and climate change on Indigenous Peoples' health, and present several case studies which outline novel Indigenous approaches and perspectives that address climate change, COVID-19 and future health threats.