INTRODUCTION

Identifying how the health community in the United States can work to more effectively address climate change requires a clear understanding of the composition of this community. Our view of this community is embodied below in an excellent working group report authored by leaders at the Centers for Disease Control and Prevention (47):

From one perspective, the U.S. health community comprises the array of institutions and professionals that provide, purchase, or oversee health care services, such as hospitals, physicians and other clinicians, health insurers, employers, governmental policy makers and regulators (15). An alternative, broader definition also includes the array of organizations and professionals that engage in population-based activities to promote health and prevent disease and injury (95). This definition recognizes the roles played by governmental public health agencies at federal, state, and local levels, as well as the array of nongovernmental institutions that contributes to population-based health activities (36).

An even broader definition is possible—one that includes the full complement of individuals and institutions whose actions influence the public's health. This definition, used by the Institute of Medicine in its recent study of public health (44), includes not only health care and public health institutions, but also actors working in many other areas that impact health, such as education, housing, business and industry, transportation, economic and community development, agriculture and food production, urban and rural planning, and environmental protection. Moreover, this definition acknowledges the critical roles played by communities and the general public in the health system—not just as consumers of health services, but also as key decision makers and leaders within the system.

This broad and encompassing view of the health system leads to a clearer understanding of the nature of health problems and the opportunities for health improvement. Because no single organization or sector within society has full control over the health problems and threats that face the public, effective solutions often require multisectoral efforts (42, 62, 82). The nation's successful quest to prevent death and disability from polio, for example, occurred through the concerted efforts of researchers, clinicians, public health professionals, and community organizations, working in tandem to protect an entire population with an effective vaccine. Addressing the health implications of climate change will require similar, multisectoral efforts. Leading such efforts requires the ability to navigate and influence a dynamic web of relationships among health community actors.

Climate change, in addition to other global environmental changes, is an increasingly important health issue. Research has focused on health outcomes associated with thermal stress (8, 55, 56, 63, 76), extreme weather events (32, 77, 91, 94), and vector-borne disease (33, 34, 54, 69, 70, 92), with some attention to estimates of future regional food yields and hunger prevalence (84). Complex climate change consequences, including those that will perturb social systems, will have impacts on health that cannot be captured by itemized tallying (64). For example, unabated climate change will likely impair regional food and water supplies, thus disrupting social and economic conditions, particularly among already poor and vulnerable populations. As a result, conflict will arise; migrant flows will increase; and a mix of violence, injury, infectious disease, malnutrition, mental disorders, and other health challenges will result.

Wealthier human societies have been assumed, at least initially, that they would be better able to buffer themselves from the more severe health-related impacts of climate change. However, events such as Hurricane Katrina and the European heat waves demonstrated that societies everywhere are vulnerable to extreme and unpredictable weather, and that wealth alone does not provide adequate protection (103). A recent British report provides an indication of the financial impact of climate change; it concludes that the eventual cost of each ton of carbon dioxide added to the environment is approximately $95 (89). Considering that the United States alone emitted 6623 million tons of carbon dioxide in 2004 (19), the financial implications are sobering. The British report also estimated that the current cost of taking action to address climate change is likely to be 1% of the global gross domestic product, but the cost of doing nothing may be up to 20% of the global gross domestic product.

Given both the magnitude of the climate change's potential health impacts and the mission of the health community, it is incumbent on the health community to (a) ensure that “its own house is in order,” (b) develop flexible and iterative action plans to address climate change at the individual, hospital, city, county, state, and national levels, and (c) advocate for and implement leadership and policies that address climate change. In this review, we summarize the status of the health community's preparation for climate change at the individual, local health department, state, and national levels, and provide specific recommendations for action at each level. Recommendations provided throughout represent both a synthesis of the literature as well as original recommendations based on the first author's public health leadership experience. We divided each set of recommendations into those specific to adaptation and mitigation strategies, according to the terminology of the Intergovernmental Panel on Climate Change. Although preparation status and recommendations vary, our crosscutting observation is that it is not enough for public health and medical care agencies and departments to develop policies and advocate change. The health community has a direct responsibility to demonstrate substantive leadership.

HEALTH PROFESSIONALS' PREPARATION

Precedent for Action

Health professionals have successfully engaged larger health issues outside strict clinical practice, for example, by their efforts in the nuclear weapons disarmament movement (52, 61, 84). Over 135,000 health professionals participated in the Nobel Peace Prize–winning organization International Physicians for Prevention of Nuclear War and helped turn political attention to the prevention of accidental or international use of nuclear weapons, in part through the publication of numerous articles depicting the immense human and environmental costs of nuclear war. A similar approach continues to be used by health professionals in the Health Care Without Harm effort, which led to the removal of many toxic agents from hospitals (38).

Current Status of Preparation

Various health organizations have begun to demonstrate leadership in the area of climate change and health ( Table 1 ). The American Medical Association does not currently have a position statement on climate change and human health; for comparison, the Australian Medical Association issued a position statement on this topic in 2004. The American Public Health Association recently posted a draft policy statement addressing the urgent threat of global climate change to public health and the environment. Both the U.S. Environmental Protection Agency (EPA) and the World Health Organization have published extensive materials related to climate change and human health (66, 68). Beyond issuing statements, the British Medical Journal recently created a “carbon council” to (a) recruit health professionals to address the links between climate and health, (b) identify the most effective policies to reduce greenhouse gas emissions, (c) establish a coalition of health professionals to act as national and international policy advocates, and (d) encourage individual lifestyle changes among health professionals (90).

Table 1

Examples of key publications and activities addressing both climate change and health by selected health leadership organizations ^a

RECOMMENDATIONS FOR HEALTH PROFESSIONALS

The following are adaptation strategies:

The following are mitigation strategies:

RECOMMENDATIONS FOR HEALTH ORGANIZATIONS

The following are adaptation strategies:

The following is a mitigation strategy:

LOCAL HEALTH DEPARTMENT PREPARATION

Some cities ¹ have taken steps to prepare for climate change, for example, by establishing real-time operational heat-watch warning systems (49). The first system was installed in Philadelphia in 1995 to alert the city's population when weather conditions posed a risk to health (50). A recent review concluded that this program saved 117 lives from 1995 to 1998 (26). Other cities have developed heat emergency plans. Bernard & McGeehin reviewed such plans from 18 cities (10). They found that one-third of the cities ² contacted lacked any written plan, and of the 10 cities that did have stand-alone heat response plans, almost one-third of these plans were perfunctory. These findings point to the urgency of developing heat emergency plans for cities before the need arises and to include objective criteria in these plans for assessing their effectiveness (20). A useful review of heat adaptation measures is provided in Reference 63; air conditioners, which are a strong protective factor against heat-related mortality, ³ are discussed in detail in References 10, 73, and 85. Television, radio, and print public service announcements that include advice and information about available heat-coping strategies have also been effective mitigating actions in cities in the eastern United States (20).

RECOMMENDATIONS FOR LOCAL HEALTH DEPARTMENTS

The following are adaptation strategies:

The following is a mitigation strategy:

HOSPITAL PREPARATION

With increasing numbers of hospitals experiencing bed shortages and capacity bottlenecks in their emergency rooms, surgical suites, and critical-care units; the aging population; and capital investment in new and replacement hospitals in the 1990s, the health care industry in the United States is in the midst of an impressive construction and hiring boom: 40% of all new jobs in the United States since 2000 have been in the health care sector (58, 71). In 2004 alone, the health care sector consumed $23 billion worth of durable medical equipment and $32 billion worth of nondurable medical equipment (96). Moreover, the industry employs 1 out of 8 Americans, directly or indirectly, and drives upwards of 15% of the gross domestic product (58). Owing to the sheer size of health care institutions, the decisions that health care purchasers make have a dramatic impact on the marketplace (17).

Given such hospital characteristics as around-the-clock operations, energy- and water-use intensity, chemical use, infection control requirements, and formidable regulatory requirements, hospitals are traditionally energy-intensive institutions. Among all United States commercial buildings, the health care industry ranks second in energy-usage intensity ( Figure 1 , see color insert). In 2005, each square foot of health care space cost an average of $2.15 in electrical and natural gas expenses. Medical facilities spend more than $6.5 billion on energy annually according to the U.S. Department of Energy and the EPA's Star program (101). Similarly, an analysis of the National Health Service in England and Wales revealed that it accounted for approximately 0.8% of all energy consumed in England and Wales in 2001 (7). Until recently, hospitals paid little attention to the energy performance and efficiency of their building infrastructure despite the fact that some costs could be reduced by energy-efficiency upgrades and better design (16).

The health care industry has demonstrated that it can be responsive to environmental concerns. The industry dramatically reduced reliance on medical waste incineration, which in 1994 was identified by the EPA as one of the largest identified dioxin sources in the United States (98). Post 1994, the number of medical waste incinerators in North America decreased from almost 5000 to fewer than 100. In addition, in 1998, the American Hospital Association signed a memorandum of understanding (40) with the EPA, with a commitment to phase out the use of mercury altogether (58). Since hospitals began working to remove mercury from their operations in 1998, more than 29 states passed laws restricting mercury-based products in their states (27).

Health care, like other major sectors, will need to move to cleaner energy sources and reduce overall energy use as the environmental and health effects of global warming become more imminent (16). Hospitals are well suited to become environmentally friendly, high-performance buildings for several reasons. First, the mission of health care implies that health care institutions should be leaders in healthy construction and operational transformations (51). Second, because hospital operators usually own their buildings, they bear the life cycle implications of their construction choices (16). Typical hospital operation consumes large amounts of energy and resources, and thus presents a great opportunity for savings from efficiency measures. For example, each dollar a nonprofit health care organization saves on energy is equivalent to generating new revenues of $20 for hospitals or $10 for medical offices (101). In 2001, leading architects and designers developed a tool for sustainable health care design known as the Green Guide for Health Care (31). It is based on the U.S. Green Building Council Leadership in Energy and Environmental Design family of products and provides the health care sector with a voluntary tool kit of best practices. Kaiser Permanente, the nation's largest nonprofit health-maintenance organization, has committed to using the Green Guide for Health Care as a framework for its entire system's building plans.

RECOMMENDATIONS FOR HEALTH CARE FACILITIES

The following are adaptation strategies:

The following is a mitigation strategy:

STATE PREPARATION

As the impact of climate on health is expected to vary by location and given the level of leadership shown on this issue by the U.S. government, it is important to address issues at the state level rather than wait for federal agencies to respond. At the time of this review, the state of California had the most wide-ranging and accessible reporting mechanism designed to address the public health–related impacts of climate change (20). The secretary of the California EPA is required to report to the governor and the state legislature biannually on the impacts on the state of global warming, including impacts on public health, and to report on mitigation and adaptation plans to combat these impacts. The 2006 report includes information on the changing prevalence of heat-related morbidity and mortality, air pollution, infectious diseases, and wildfires associated with climate change, as well as a discussion of adaptation costs, environmental justice issues, and research needs. Many other states have developed climate action plans designed to identify and evaluate feasible and effective policies to reduce greenhouse gas emission, but few include a discussion of the relationship between climate and health. As of July 2006, 29 states and Puerto Rico have completed, or are working on, action plans (100), although only three states—Colorado (102), Massachusetts (37), and Washington (30)—have explicitly mentioned the impact of climate change on human health. Additionally, the nongovernmental organization Physicians for Social Responsibility prepared 15 state reports ⁵ on the public health implications of climate change. In general, the Physicians for Social Responsibility reports describe how climate change could affect various environmental parameters (e.g., air quality, water, extreme weather, and so forth), how each environmental parameter can affect health, the steps the state has taken to confront climate change, and steps for individual action, as well as useful references.

RECOMMENDATIONS FOR STATES

The following are adaptation strategies:

The following are mitigation strategies:

NATIONAL PREPARATION

The first U.S. national assessment of the potential consequences of climate variability and change was completed in 2000 (79). During the first assessment process, the health sector group consulted with other experts and reviewed hundreds of peer-reviewed studies, government reports, and limited ongoing research on the potential links between climate events, human exposure, and health impacts to synthesize the state of the science and to identify adaptation measures (9). Five categories of health outcomes associated with climate change were identified in the first health sector assessment: (a) temperature-related morbidity and mortality (63), (b) health effects of extreme weather events (32), (c) air-pollution-related health effects (11), (d) water- and food-borne diseases (83), and (e) insect-, tick-, and rodent-borne diseases (33). In the final report, the authors concluded that vigilance in the maintenance and improvement of public health systems and their responsiveness to changing climate should help protect the U.S. population from adverse health outcomes driven by climate change (79).

The original health sector assessment was updated in 2006 (23). The authors concluded that the literature published since the original health sector assessment supported previous conclusions and synthesized new data refining quantitative exposure-response relationships for several health outcomes, in particular, extreme heat events and air pollution. They also observed that the United States continues to have a high capacity to plan for and respond to climate change, although relatively little progress has been noted in the literature on implementing adaptive strategies and measures. To this end, most informative is the White House report on the response to Hurricane Katrina (28). The surprisingly forthright report details 17 critical challenges as well as the subsequent lessons learned, and provides 125 recommendations designed to institutionalize a comprehensive National Preparedness System and foster a new, robust culture of preparedness.

A major continuing challenge for health researchers is to undertake research that will assist society in understanding and averting systematic dangers to health. McMichael identifies three categories of research designed to better understand health risks posed by global environmental change (65). First, empirical studies are needed to elucidate how variations in environmental and ecological systems affect health. Second, the health community must address the question, Are global environmental changes already affecting health? Gleaning such evidence is challenging in the early stages of such research owing to high signal-to-noise ratios, and there is a pressing need to develop pattern-recognition methods applicable to such scenarios. The third research needed is to make credible estimates of future changes in the health risks due to plausible scenarios of ongoing changes in large environmental systems (4, 104). Other specific research goals, including the need to (a) develop innovative approaches to analyze weather and climate in relation to health, (b) set up long-term data sets to answer key questions, and (c) improve our understanding of how to incorporate outputs from global climate models into human health studies, are discussed in detail in References 11, 32, 33, 60, 63, 66, 67, and 83.

Research must be coupled with leadership in order to achieve measurable success. One illustrative example is the successful focus on children's environmental health in the 1990s (46). Recognizing the improvements that a children's health initiative could bring about, President Clinton ordered that all agencies develop strategies to improve the health of children and mandated twice-yearly cabinet-level meetings to make it happen. Several important efforts, including the proposal for the National Children's Study, grew out of this initiative.

RECOMMENDATIONS APPLICABLE AT THE NATIONAL LEVEL

The following are adaptation strategies:

The following are mitigation strategies:

CONCLUSION

We provide recommendations for action on climate change at the individual, hospital, local health department, state, and national level. Additional recommendations can be found in References 4, 14, 20, 22, 29, 35, 59, 78, and 86. Public health agencies and medical institutions, however, must do more than just advocate environmental responsibility and policy change; the health community also has a direct responsibility to demonstrate substantive leadership.

The health community has achieved much using intervention strategies. Sanitation and immunization programs have had remarkable success for infectious diseases, as have counter-advertising taxation and environmental regulation for tobacco disease reduction. Similar but more aggressive strategies will be required for a threat of the scale of climate change given its generational consequences. The health community is slowly becoming more carbon literate, for example, with the formation of the British Medical Journal's carbon council; the establishment of real-time operational heat-related warning systems in several major U.S. cities; the publication of the Green Guide to Health Care; the founding of the organization Hospitals for a Healthy Environment; California Governor Schwarzenegger's directive that the California EPA provide a biannual report on the impacts of global warming there, including the impact of climate on health; and the publication of the U.S. national assessment of the potential consequences of climate variability and change in 2000 and its update in 2006. However, on the basis of the Hippocratic principle, “first, do no harm,” these activities alone are not sufficient steps for a community.

The extent of climate change's impacts on health will be partially determined by policies designed to increase the ability of individuals and societies to cope with future challenges (21). Policy makers have a variety of tools for addressing climate change; not all will be equally effective, and some may themselves create adverse health impacts. In environmental health, aggressive removal of sources—for example, lead—or outright bans—for example, of certain pesticides—have the clearest record of success. Similarly, for climate policies to be health protective, the health community must become much more engaged in these debates. Successful environmental health protection programs of the past required effective priority setting, extensive public and policy education, the accounting for and public reporting of hazards, substantial increased regulation, and evaluation of overall successes and failures. It will also be important to guide mitigation and adaptation measures in nonhealth sectors such that they avoid public health impacts or, even better, help achieve other public health goals. This important topic is addressed in an accompanying chapter in this volume (87).

The threats to health from climate change have fearsome precedent in the pandemics of the past. With the plague, for example, nearly one-third of Europe's population succumbed; the nostrums of the day, such as breathing through perfumed handkerchiefs, were worthless. Looking back, we see how simple sanitation and vermin removal could have blunted or even ended the pestilence. Then, more knowledgeable and effective health leadership could have saved millions of lives. Today, we are on the threshold of the next great pandemic. We cannot dismiss the threat because remedies are costly or inconvenient. Future generations who bear the brunt of our failure may look back at a “criminal generation”—one that failed to prevent catastrophe even when it had the tools. Even if failed leaders face condemnation, at a minimum, let it be said that the “health people” did all we could to minimize our own environmental impacts and to alert our leaders and society of the gravity of the endangerment.

SUMMARY POINTS

disclosure statement

The authors are not aware of any biases that might be perceived as affecting the objectivity of this review.