“The reason we are here is to be able to inform the kinds of decisions that have to be made both in terms of limiting the extent of climate change and in terms of protecting the vulnerable people who are going to be experiencing the risks.”—John Balbus
Climate change poses risks to human health and well-being through shifting weather patterns, increases in frequency and intensity of heat waves and other extreme weather events, rising sea levels, ocean acidification, and other environmental effects. Those risks occur against a backdrop of changing socioeconomic conditions, medical technology, population demographics, environmental conditions, and other factors that are important in determining health. Models of health risks that reflect how health determinants and climate changes vary in time and space are needed so that we can inform adaptation efforts and reduce or prevent adverse health effects. Robust health risk models could also help to inform national and international discussions about climate policies and the economic consequences of action and inaction.
However, the development of models of health risks that result from climate change has been slow. Inherent uncertainty in what health and socioeconomic trends the future will bring, uncertainty about the links between climate-change events and health outcomes, and the variability and complexity of human health and disease are a few of the hurdles that health-risk modelers are endeavoring to overcome. Interest in resolving some of the challenges facing health effects modelers and health scientists led the National Research Council’s Standing Committee on Emerging Science for Environmental Health Decisions (ESEH) to hold a workshop on November 3–4, 2014, in Washington, DC, to explore new approaches to modeling the human health risks of climate change. The workshop Statement of Task is provided in Appendix A.
Key topics addressed during the workshop included
- The state of development of health-risk models.
- Integrated systems-based approaches to health modeling.
- Approaches to generalizing and scaling up of health-risk models.
- Integration of health risks into models of aggregated impacts of climate change.
The workshop focused only on health risks of climate, not all potential health implications. Throughout the workshop, the discussions highlighted examples of current application of models, research gaps, lessons learned, and potential next steps to improve modeling of health risks associated with climate change.
In his opening comments, John Balbus, the senior adviser for public health in the US National Institute of Environmental Health Sciences and a member of the workshop planning committee, emphasized that the workshop would be different from previous meetings of the ESEH committee. The committee “has been focusing on the basic science of environmental health, toxicology, and biology,” he said. Balbus noted that the ESEH committee has been discussing the potential for a workshop on health effects of climate change for many years, and he applauded the committee for its vision in including the health effects of climate change as an important emerging topic in the scope of environmental health.
“The timing is perfect for this workshop,” Balbus emphasized. The day before the workshop began, the Intergovernmental Panel on Climate Change1 issued its starkest warning yet on global warming. In the preceding months, the World Health Organization (WHO) had held its first summit on climate change and health in advance of the UN Climate Summit, which in 2014 for the first time included a thematic session on climate change and health. More recently, WHO released a new assessment of the global burden of disease linked to climate change on the basis of cutting-edge approaches to estimation.2
Also during 2014, the US Department of Health and Human Services held its first climate-change briefing. In May 2014, the US Global Change Research Program’s Third National Climate Assessment provided the first federal integrated effort to model health outcomes and exposures associated with a variety of events related to climate change, including increases in heat, air pollution, and populations of arthropod disease vectors (such as ticks and mosquitoes). A follow-up special report on climate and health that will quantify those health outcomes is being prepared.
Balbus outlined the goals of the workshop in light of the many interrelated national and international projects:
- Bring together different teams that are conducting climate-change modeling projects in different settings, and assess the state of the science.
- Think about questions that need to be answered to make decisions about how to protect human health and well-being. Do we have models to answer the questions? Do we have the information that we need to put mitigation, prevention, or adaptation measures into place to protect health in the setting of a changing climate?
- Brainstorm how to move forward. What partnerships are needed? What approaches do we want to look at? How will we get the best teams together to take us to the next level?
1An international, intergovernment body established by the UNUN Environment Programme and the World Health Organization to provide scientific views on the state of knowledge about climate change.
On workshop day 1, Balbus welcomed participants and provided framing for the workshop. In the first session, summarizing the state of knowledge, Jan Semenza, of the European Centre for Disease Prevention and Control, described some of the current challenges associated with modeling and quantifying effects of climate change. Ben Zaitchik, of Johns Hopkins University, discussed emerging climate-change models, datasets, and applications. The opening session concluded with George Luber, of the US Centers for Disease Control and Prevention (CDC) who explained how models of health risks are being used to improve community preparedness.
The second session focused on the state of development of models of health risks that result from climate change; it was moderated by Linda Wennerberg, of the US National Aeronautics and Space Administration (NASA). Sari Kovats, of the London School of Hygiene and Tropical Medicine, provided an overview of the quantitative risk-assessment approach to modeling of the health effects of climate change. Michelle Bell, of Yale University, talked about climate and health effects of heat stress and air pollution. Juli Trtanj, of the US National Oceanic and Atmospheric Administration, told attendees about what is known on the subject of climate and waterborne diseases. Nick Ogden, of the Public Health Agency of Canada, described how modeling is and can be used to address our understanding of how vectorborne diseases are affected by climate change. All the speakers participated in a panel discussion on health-risk models. They were joined by Charles Benjamin Beard (Ben Beard), of CDC; Mary Hayden, of the University Corporation for Atmospheric Research; and Erin Lipp, of the University of Georgia.
The final session of day 1 focused on how systems approaches can be used to understand future vulnerabilities. The session was moderated by Gary Geernaert, of the US Department of Energy (DOE). Georges Benjamin, of the American Public Health Association, discussed a population-based approach to identifying climate-change effects. Joshua Elliott, of the University of Chicago and Argonne National Laboratory, told the audience how a systems approach has shed light on climate-change effects on agriculture and human health. Richard Jackson, of the University of California Los Angeles, discussed urbanization, climate change, and human health. All the speakers participated in a panel discussion on systems thinking and modeling of the health effects of climate change. They were joined by Molly Brown, of NASA), and Gregory Glass, of the University of Florida.
Workshop day 2 began with a session focused on incorporation of health risks into the aggregated impact of climate change. In addition to moderating the session, Kristie Ebi, of ClimAdapt, LLC, briefly recapitulated the presentations and discussions of the first day. Anthony Janetos, of Boston University, spoke about integration of climate-change impact models, including the state of the art and long-term goals. The session ended with a panel discussion on conceptual directions for research on integrating climate-change impact models, including Janetos, Kovats, Semenza, and Stéphane Hallegatte of the World Bank.
The final event of the workshop was a panel discussion on practical next steps to improve climate-change impact models. The panelists were Balbus; Anne Grambsch, of the US Environmental Protection Agency; Trtanj; Robert Vallario, of DOE; and Peter Berry, of Health Canada.
The workshop was attended by 65 persons, and another 81 joined via webcast. Workshop presentations and archived videos are available through the ESEH Web site.3 The workshop agenda and a list of in-person workshop attendees can be found in Appendixes B and C, respectively.
This report summarizes the presentations and discussions that took place during the workshop. It is organized by the major themes that emerged. Chapter 2 describes what we know about health effects of climate change, why models of health effects are needed, and the major hurdles that need to be overcome to develop robust models. Chapter 3 examines recent efforts to model health effects of climate change, including effects caused by changes in air quality, water quality, and arthropod disease vectors. It includes information about challenges to modeling of the effects and reasons for optimism. Chapter 4 discusses why and how to incorporate systems thinking into the modeling of the health effects of climate change. Chapter 5 summarizes ideas shared during the workshop for moving modeling efforts forward.
This publication is a factual summary of the presentations and discussions at the workshop written by rapporteurs. The views presented here are those of the individual workshop participants and do not necessarily represent all workshop participants, the organizing committee, or the National Research Council.