Jeremy J. Hess

• MD, MPH
• Professor at University of Washington

Objective The 2021 Pacific Northwest heat dome was Washington state’s deadliest recorded weather event and presented unprecedented response challenges to the state’s health sector. Understanding the impacts of this extreme heat event (EHE) on the sector as well as the barriers to and facilitators of implementing effective heat response is critical...

This JAMA Insights discusses the need to fully assimilate evidence from observed and projected effects of climate change on health and invest in developing and implementing effective health protection from preventable climate-sensitive conditions.

Importance Flooding is a major environmental hazard, with events increasing in intensity and frequency in the context of climate change. Floods cause significant health and economic impacts, particularly among vulnerable populations, including older adults. However, comprehensive analyses of the health consequences of flooding remain limited. Obje...

Executive summary Despite the initial hope inspired by the 2015 Paris Agreement, the world is now dangerously close to breaching its target of limiting global multiyear mean heating to 1·5°C. Annual mean surface temperature reached a record high of 1·45°C above the pre-industrial baseline in 2023, and new temperature highs were recorded throughout...

Objectives Extreme heat events (EHEs) are associated with excess healthcare utilization but specific impacts on emergency department (ED) operations and throughput are unknown. In 2021, the Pacific Northwest experienced an unprecedented heat dome that resulted in substantial regional morbidity and mortality. The aim of this study was to examine its...

This JAMA Insights introduces the new series on climate change intended to inform readers about the associations between climate change and health.

Executive Summary The Lancet Countdown is an international research collaboration that independently monitors the evolving impacts of climate change on health, and the emerging health opportunities of climate action. In its eighth iteration, this 2023 report draws on the expertise of 114 scientists and health practitioners from 52 research institut...

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 resea...

Background: The adverse health impacts of climate change are increasingly apparent and the need for adaptation activities is pressing. Risks, drivers, and decision contexts vary significantly by location, and high-resolution, place-based information is needed to support decision analysis and risk reduction efforts at scale. Methods: Using the In...

U.S. wildfire activity has increased over the past several decades, disrupting the systems and infrastructure that support community health and resilience. As the cumulative burden of wildfire damage is projected to increase, understanding an effective community recovery process is critically important. Through qualitative interviews with leaders o...

Background Increasingly frequent and intense extreme heat events (EHEs) are indicative of climate change impacts, and urban areas’ social and built environments increase their risk for health consequences. Heat action plans (HAPs) are a strategy to bolster municipal EHE preparedness. The objective of this research is to characterize municipal inter...

The impacts of anthropogenic climate change remain largely unquantified. Here we detail and address limitations in existing methods for attributing health impacts to climate change, including the representation of the climate-health relationship, choices in calculating counterfactual temperatures, assessment of long-term trends and individual event...

Objectives. To examine commonalities and gaps in the content of local US heat action plans (HAPs) designed to decrease the adverse health effects of extreme heat. Methods. We used content analysis to identify common strategies and gaps in extreme heat preparedness among written HAPs in the United States from jurisdictions that serve municipalities...

Background: Recent scientific developments made it possible to quantify the health impacts of climate change. However, limited health attribution studies have been conducted to date. Objectives: We address limitations in existing methods using as case study an assessment of heat mortality attributable to human-induced climate change in the Canton o...

As the impacts of climate change increasingly and disproportionately affect indigenous peoples, equitable approaches to regional climate change adaptation must center the voices, needs, and priorities of Indigenous communities. Although the tribal climate change principles identify actionable recommendations to address the unique needs of Indigenou...

Objective: Although extreme heat can impact the health of anyone, certain groups are disproportionately affected. In urban settings, cooling centers are intended to reduce heat exposure by providing air-conditioned spaces to the public. We examined the characteristics of populations living near cooling centers and how well they serve areas with hi...

Background As the health implications of climate change become more apparent, agencies and institutions across the United States are developing recommendations for state and territorial health agencies (S/THAs) to implement evidence-informed climate and health adaptation strategies. The CDC established the Building Resilience Against Climate Effect...

Heat is a dangerous hazard that causes acute heat illness, chronic disease exacerbations, adverse pregnancy outcomes, and a range of injuries. Risks are highest during extreme heat events (EHEs), which challenge the capacity of health systems and other critical infrastructure. EHEs are becoming more frequent and severe, and climate change is drivin...

This study used a health care claims data set of enrollees in commercial and Medicare Advantage insurance plans to assess the association between the June 2021 heat wave and the rates of emergency department visits in Portland, Oregon, and Seattle, Washington.

Objective: To characterize US State and Territorial Health Agencies' (S/THA) climate change adaptation activities and priorities to facilitate appropriate investments, skills development, and support that will strengthen health sector capacity in response to a changing climate. Design: In 2021, we conducted an online survey of S/THA staff reques...

Looming climate change health impacts among rural communities will require a robust health system response. To reduce health inequities and promote climate justice, rural local health departments (LHDs) must be adequately resourced and supported to engage in climate change mitigation and adaptation policy and program development and implementation....

The 2022 report of the Lancet Countdown is published as the world confronts profound and concurrent systemic shocks. Countries and health systems continue to contend with the health, social, and economic impacts of the COVID-19 pandemic, while Russia's invasion of Ukraine and a persistent fossil fuel overdependence has pushed the world into global...

Background While year-round exposure to pollen is linked to a large burden of allergic diseases, location-specific risk information on pollen types and allergy outcomes are limited. We characterize the relationship between acute exposure to tree, grass and weed pollen taxa and two allergy outcomes (allergic rhinitis physician visit and prescription...

Data from satellite instruments provide estimates of gas and particle levels relevant to human health, even pollutants invisible to the human eye. However, the successful interpretation of satellite data requires an understanding of how satellites relate to other data sources, as well as factors affecting their application to health challenges. Dra...

Background Previous research has shown airborne pollen concentrations and phenology in allergenic plants are changing. Additionally, variations in seasonal climate are known to affect pollen phenology in trees, weeds, and grasses. Objective We investigated localized trends in pollen concentrations and pollen phenology over time, and the effect of...

Introduction: Extreme heat is a significant cause of morbidity and mortality, and the incidence of acute heat illness (AHI) will likely increase secondary to anthropogenic climate change. Prompt diagnosis and treatment of AHI are critical; however, relevant diagnostic and surveillance tools have received little attention. In this exploratory cross...

Introduction: Essential nutrients, including carbohydrates, proteins, fats, vitamins, and minerals, are required for human health and development. Inadequate intake can negatively affect development and result in a wide range of adverse health outcomes. Rice, maize, and wheat provide over 60% of the world's food energy intake. Atmospheric carbon di...

Climate and weather directly impact plant phenology, affecting airborne pollen. The objective of this systematic review is to examine the impacts of meteorological variables on airborne pollen concentrations and pollen season timing. Using PRISMA methodology, we reviewed literature that assessed whether there was a relationship between local temper...

Since 2001, a synthesizing element in Intergovernmental Panel on Climate Change assessment reports has been a summary of how risks in a particular system could change with additional warming above pre-industrial levels, generally accompanied by a figure called the burning embers. We present a first effort to develop burning embers for climate chang...

Pollen allergies have negative impacts on health. Information about airborne pollen concentration can improve symptom management by guiding choices affecting timing of medicines and pollen exposure. Observations provide accurate pollen concentrations at point locations. However, in the contiguous United States and southern Canada (CUSSC), observati...

As the nation’s public health agency, CDC recognizes that climate change poses a multifaceted and potentially significant threat to domestic public health. To facilitate climate change preparedness in public health, the agency developed the Climate and Health Program, which is housed in the National Center for Environmental Health. The program’s mi...

The Lancet Countdown is an international collaboration established to provide an independent, global monitoring system dedicated to tracking the emerging health profile of the changing climate. The 2020 report presents 43 indicators across five sections: climate change impacts, exposures, and vulnerabilities; adaptation, planning, and resilience...

The health risks of a changing climate are immediate and multifaceted. Policies, plans, and programs to reduce climate-related health impacts exist, but multiple barriers hinder the uptake of these strategies, and information remains limited on the factors affecting implementation. Implementation science-a discipline focused on systematically exami...

Climate change has altered global to local weather patterns and increased sea levels, and it will continue to do so. Average temperatures, precipitation amounts, and other variables such as humidity levels are all rising. In addition, weather variability is increasing, causing, for example, a greater number of heat waves, many of which are more int...

The question of whether, how, and to what extent climate change is affecting health is central to many climate and health studies. We describe a set of formal methods, termed detection and attribution, used by climatologists to determine whether a climate trend or extreme event has changed and to estimate the extent to which climate change influenc...

Background: Modeling suggests that climate change mitigation actions can have substantial human health benefits that accrue quickly and locally. Documenting the benefits can help drive more ambitious and health-protective climate change mitigation actions; however, documenting the adverse health effects can help to avoid them. Estimating the health...

Climate change is emerging as an important driver of disease incidence, and a wait and see approach invites unnecessary risk, write Jeremy Hess and colleagues. Governments, funders, researchers, and practitioners must act now

Tracking concentrations of regional airborne pollen is valuable for a variety of fields including plant and animal ecology as well as human health. However, current methods for directly measuring regional pollen concentrations are labor-intensive, requiring special equipment and manual counting by professionals leading to sparse data availability i...

Plain Language Summary Recent advances in satellite remote sensing enable observation‐based tracking of climate change and air pollution with relatively high spatial resolution globally. The 2018 NASA Health and Air Quality Applied Science Team (HAQAST) “Indicators” Tiger Team launched a collaboration between ~20 NASA‐supported scientists and civil...

Rising emissions of greenhouse gases in the atmosphere have warmed the planet substantially and are also accompanied by poor air quality. The increased prevalence of allergic airway disease worldwide can be partially attributed to those global environmental changes. Climate change and air pollution pose adverse impacts on respiratory allergies, and...

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 populati...

Objectives. To develop a set of indicators to guide and monitor climate change adaptation in US state and local health departments. Methods. We performed a narrative review of literature on indicators of climate change adaptation and public health service capacity, mapped the findings onto activities grouped by the Centers for Disease Control and P...

Pollen is a common allergen that causes significant health and financial impacts on up to a third of the population of the USA. Knowledge of the main pollen season can improve diagnosis and treatment of allergic diseases. Our objective in this study is to provide clear, quantitative visualizations of pollen data and make information accessible to m...

The Lancet Countdown is an international, multidisciplinary collaboration, dedicated to monitoring the evolving health profile of climate change, and providing an inde pendent assessment of the delivery of commitments made by governments worldwide under the Paris Agreement. The 2019 report presents an annual update of 41 indicators across five key...

The Lancet Countdown is an international, multidisciplinary collaboration, dedicated to monitoring the evolving health profile of climate change, and providing an independent assessment of the delivery of commitments made by governments worldwide under the Paris Agreement. The 2019 report presents an annual update of 41 indicators across five key d...

Background: The Global Burden of Disease (GBD) study, coordinated by the Institute for Health Metrics and Evaluation (IHME), produces influential, data-driven estimates of the burden of disease and premature death due to major risk factors. Expanded quantification of disease due to environmental health (EH) risk factors, including climate change,...

We explore whether the timing and burden of paediatric window fall injuries in the Seattle area have changed with higher temperatures and increased air conditioning (AC) prevalence. Using hospital trauma registry records from 2005 to 2017, along with population estimates from the National Center for Health Statistics, we calculate trauma incidence...

Dengue fever (DF)is the most important mosquito-transmitted viral disease causing a large economic and disease burden in many parts of the world. Most DF research focuses on Latin America and Asia, where burdens are highest. There is a critical need for studies in other regions where DF is an important public health problem but less well-characteri...

Background: Abundant historical evidence demonstrates how environmental changes can affect social stability and, in turn, human health. A rapidly growing body of literature, largely from political science and economics, is examining the potential for and consequences associated with social instability related to current climate change. However, co...

Significance Heat early warning systems and action plans have been shown to reduce risks of heat exposure, and best practice recommends that plans be built around local epidemiologic evidence and emergency management capacity. This evaluation provides useful information for heat early warning system and action plan administrators regarding the temp...

In coming decades, sea level rise associated with climate change will make some communities uninhabitable. Managed retreat, or planned relocation, is a proactive response prior to catastrophic necessity. Managed retreat has disruptive health, sociocultural, and economic impacts on communities that relocate. Health impacts include mental health, soc...

Introduction Climate change will impose significant health impacts. Although we know health professionals should play a critical role in protecting human health from climate change, their preparedness to engage with these issues worldwide is unclear. This study aims to map the range and nature of existing evidence regarding health professionals’ kn...

The 2018 Adaptation Gap Report has two parts. First, it provides an overview of the status and trends of the adaptation gap in terms of vulnerability to climate change, adaptation costs and finance, and countries’ adaptation commitments and actions. Second, the report undertakes an in-depth assessment of the adaptation gap in health.

The following four key messages derive from the Lancet Countdown’s 2018 report: 1 Present day changes in heat waves, labour capacity, vector-borne disease, and food security provide early warning of the compounded and overwhelming impact on public health that are expected if temperatures continue to rise. Trends in climate change impacts, exposures...

There is consensus among 97% of scientists that anthropogenic climate change is occurring and international agreement of the grave threat it poses.1,2 A Lancet Commission declared climate change “the biggest global health threat of the 21st century” with “potentially catastrophic risk to human health.”3,4 Emergency medicine (EM) is already on the f...

Background: Ahmedabad implemented South Asia's first heat action plan (HAP) after a 2010 heatwave. This study evaluates the HAP's impact on all-cause mortality in 2014-2015 relative to a 2007-2010 baseline. Methods: We analyzed daily maximum temperature (Tmax)-mortality relationships before and after HAP. We estimated rate ratios (RRs) for daily...

Vulnerability and adaptation assessments can provide valuable input to foster climate-resilient health systems. However, these assessments often do not explore the potential health risks of climate change far outside the range of recent experience with extreme weather events and other climate-related hazards. Climate and health stress tests are des...

Background: Climate change is the biggest global health threat of the 21st century. Medical students will lead the health sector responses and adaptation efforts in the near future, yet little is known in China about their knowledge, perceptions and preparedness to meet these challenges. Methods: A nationwide study was conducted at five medical uni...

Climate change poses a range of current and future health risks that health professionals need to understand, track, and manage. However, conventional monitoring and evaluation (M&E) as practiced in the health sector, including the use of indicators, does not adequately serve this purpose. Improved indicators are needed in three broad categories: (...

One of the most concerning environmental effects of climate change is rising levels of extreme heat, which already poses serious risks in many parts of the world. In June and July 2015, we collected weekly heat exposure data using area and personal temperature monitoring in Ahmedabad, Gujarat. The study was conducted at four different traffic junct...

Avian influenza virus (AIV) is a major health threat to both avian and human populations. The ecology of the virus is driven by numerous factors, including climate and avian migration patterns, yet relatively little is known about these drivers. Long-distance transport of the virus is tied to inter- and intra-continental bird migration, while enhan...

Introduction Climate change is causing rising levels of extreme heat. Traffic police workers form a vulnerable group exposed to high atmospheric temperature in temperate countries like India. A heat exposure assessment among traffic police has not been previously undertaken in an Indian city. Therefore, a pilot study was conducted with plans for an...

One of the most concerning environmental effects of climate change is rising levels of extreme heat, which already poses serious risks in many parts of the world. In June and July 2015, we collected weekly heat exposure data using area and personal temperature monitoring in Ahmedabad, Gujarat. The study was conducted at four different traffic junct...

Background: Significant mitigation efforts beyond the Nationally Determined Commitments (NDCs) coming out of the 2015 Paris Climate Agreement are required to avoid warming of 2 °C above pre-industrial temperatures. Health co-benefits represent selected near term, positive consequences of climate policies that can offset mitigation costs in the shor...

The past 150 years have seen substantial public health advances globally. However, the intensive exploitation of energy and resources, the associated disruption of earth systems, and the resulting decline in some ecosystem services, threaten these advances. The risks are driven by global climate change, biodiversity loss, land use alterations, depl...

Background: Environmental heat exposure is a public health concern. The impacts of environmental heat on mortality and morbidity at the population scale are well documented, but little is known about specific exposures that individuals experience. Objectives: The first objective of this work was to catalyze discussion of the role of personal hea...

Climate change and health was established as a formal field of endeavor in the early 1990s, with the number of publications increasing since the mid-2000s. The key findings in assessment reports from the Intergovernmental Panel on Climate Change in 1995, 2001, 2007, and 2014 indicate the progress in understanding the magnitude and pattern of the he...

Background: Sri Lanka is vulnerable to floods and other hydro-meteorological disasters. Climate change is projected to increase the intensity of these events. Objective: This study aimed to assess the flood preparedness in healthcare facilities in Eastern Province. Design: This was a cross-sectional, descriptive, mixed methods study conducted in Tr...

Recent studies suggest that heat exposure degrades work productivity, but such studies have not considered individual- and workplace-level factors. Forty-six tree fruit harvesters (98% Latino/a) from six orchards participated in a cross-sectional study in Central/Eastern Washington in 2015. The association between maximum measured work-shift Wet Bu...

Background Motor vehicle crashes are a leading cause of injury mortality. Adverse weather and road conditions have the potential to affect the likelihood of motor vehicle fatalities through several pathways. However, there remains a dearth of assessments associating adverse weather conditions to fatal crashes in the United States. We assessed trend...

Extreme heat is a leading weather‐related cause of morbidity and mortality, with heat exposure becoming more widespread, frequent, and intense as climates change. The use of heat early warning and response systems (HEWSs) that integrate weather forecasts with risk assessment, communication, and reduction activities is increasingly widespread. HEWSs...

Purpose This study aims to evaluate home-hospital implications for facility management (FM) and, in particular, ED crowding. Home-hospital programs, in which select patients receive hospital-level care at home, can extend hospital facility capacity. Emergency department (ED) crowding, a sensitive hospital capacity indicator, is associated with uns...