default header
25 October 2007
Concern Grows About Health Risks Posed by Climate Change
Floods, heat waves, insect-borne diseases threaten global health security
Washington -- Risks to international public health from floods, heat waves and droughts arising from climate change are becoming the focus of global health organizations and officials around the world.
A range of health problems is expected to accompany rising temperatures worldwide, especially in developing countries, according to Climate Change 2007: Impacts, Adaptation and Vulnerability, part two of the Intergovernmental Panel on Climate Change (IPCC) fourth assessment report.
“The health of all individuals is influenced by the health of people, animals and the environment around us,” Dr. Julie Gerberding, director of the U.S. Centers for Disease Control and Prevention (CDC), said October 23 in testimony before the Senate Committee on Environment and Public Works. “Many trends within this larger, interdependent ecologic system influence public health on a global scale, including climate change.”
On the same day in Geneva, the World Health Organization (WHO) announced that its theme for World Health Day on April 7, 2008, would be “protecting health from climate change.”
“We need to put public health at the heart of the climate change agenda," WHO Director-General Dr. Margaret Chan said in a statement. "This includes mobilizing governments and stakeholders to collaborate on strengthening surveillance and control of infectious diseases, safer use of diminishing water supplies and health action in emergencies."
WARMING WORLD
“Warming of the climate system is unequivocal,” read the IPCC Summary for Policymakers, released February 1. Most of the warming over the past 50 years “is likely to have been due to the increase in greenhouse gas concentrations,” and human activity “very likely” is the source of these gases, it said.
The report concludes, with what it says is about 90 percent certainty, that recent, rapid climate change is the result of increased global atmospheric concentrations of the greenhouse gases carbon dioxide, methane and nitrous oxide, likely generated by emissions from human use of fossil fuels.
In response to the warming, a growing body of evidence shows discernible, physically consistent changes. These include increases in global average air temperature and atmospheric temperatures above the surface, increases in surface and subsurface ocean water temperature, widespread melting of snow, decreases in the extent and thickness of Arctic sea ice, decreases in the extent of glacier and small ice caps, and a rise in global mean sea level.
On the ground, such climate variability and change can increase the occurrence and intensity of natural events like heat waves, floods, droughts and storms, directly affecting the health of millions of people.
CLIMATE AND HEALTH
According to the IPCC, health is at risk from a range of climate-related causes, including increases in malnutrition and consequent disorders; deaths, disease and injury due to heat waves, floods, storms, fires and droughts; diarrheal diseases; and a change in the distribution of some infectious-disease carriers (mosquitoes, ticks).
“WHO has carried out both qualitative reviews and quantitative assessments of the health risks posed by climate change,” Dr. David Heymann, assistant director-general for communicable diseases, said in written testimony to the Senate committee. “The organization concludes that the health hazards posed by climate change are significant, wide-ranging, distributed throughout the globe and difficult to reverse.”
Climate change also is expected to have mixed effects, including a decrease or increase of the range and transmission potential of malaria in Africa, and some benefits, such as fewer deaths from cold exposure.
“Overall, it is expected that these benefits will be outweighed by the negative health effects of rising temperatures world-wide, especially in developing countries,” the report read.
“The balance of positive and negative health impacts will vary from one location to another,” it continued, “and will alter over time as temperatures continue to rise. Critically important will be factors that directly shape the health of populations such as education, health care, public health prevention and infrastructure and economic development.”
GREATEST RISKS
According to WHO, the greatest risks are to populations living in small-island developing states, mountain regions, water-stressed regions, megacities in developing nations (particularly Asian mega-delta cities), and people who are poor and poorly protected by health services.
“Because some climate change is now inevitable,” Heymann said, “it will be necessary to strengthen health systems to protect public health from the associated risks.”
Bolstering health systems should include greater emphasis on environmental and socioeconomic determinants of health risks, and actions already part of the health sector, such as environmental protection, disease surveillance and response, and health action in crises.
These could be supported by climate-specific interventions for heat wave and vector-borne disease early warning systems, and supporting development choices that enhance health in sectors such as agriculture and water management.
“Health and the environment are closely linked,” CDC’s Gerberding said. “Because of this linkage, it is also important that potential health effects of environmental solutions be fully considered.”
The full text of the IPCC fourth assessment report is available on the organization’s Web site.
More information on climate change and human health is available at the WHO Web site.
(USINFO is produced by the Bureau of International Information Programs, U.S. Department of State. Web site: http://usinfo.state.gov)
Video: Climate Change