Human-induced climate change will affect the lives of most populations in the next decade and beyond. It will have greatest, and generally earliest, impact on the poorest and most disadvantaged populations on the planet. Changes in climatic conditions and increases in weather variability affect human wellbeing, safety, health and survival in many ways. Some impacts are direct-acting and immediate, such as impaired food yields and storm surges.
Other health effects are less immediate and typically occur via more complex causal pathways that involve a range of underlying social conditions and sectors such as water and sanitation, agriculture and urban planning. Climate change adaptation is receiving much attention given the inevitability of climate change and its effects, particularly in developing contexts, where the effects of climate change will be experienced most strongly and the response mechanisms are weakest.
Financial support towards adaptation activities from various actors including the World Bank, the European Union and the United Nations is increasing substantially. With this new global impetus and funding for adaptation action come challenges such as the importance of developing adaptation activities on a sound understanding of baseline community needs and vulnerabilities, and how these may alter with changes in climate.
The global health community is paying heed to the strengthening focus on adaptation, albeit in a slow and unstructured manner. The aim of this paper is to provide an overview of adaptation and its relevance to global health, and highlight the opportunities to improve health and reduce health inequities via the new and additional funding that is available for climate change adaptation activities.
Author: Kathryn J BowenSharon Friel
Health Impact
Climate change will have a strong impact on human health. As climate change brings tropical weather to higher latitudes, tropical diseases like the West Nile virus will follow. Ecosystem disruption will make the outbreak of water-borne diseases more likely.
Air pollution, which in Canada is largely caused by fossil-fuel use, is already a scourge on public health. Climate change will make smog more intense, and will lead to even higher rates of asthma and heart disease. The most devastating casualties will be inhabitants of poor countries, where there is little infrastructure to deal with changing water tables and increased extreme weather. Among the world’s least privileged, the potential for climate-induced disaster is enormous.
Deadly heat
Climate change will cause high-latitude regions, like Canada, to warm drastically. With tropical heat comes tropical illnesses, and large increases in heat-related deaths.
Heat can aggravate health problems, particularly for the old, the young and the ill. For example, Montreal currently has approximately 70 annual heat-related deaths, while Toronto has 20. According to the World Health Organization, these figures are expected to climb to 460 and 290 respectively by 2020 due to climate change.
A hotter world is a sicker world
Rising average temperatures will likely extend the ranges of disease-carrying organisms like mosquitoes, rodents and bats. In 1998, drought followed by heavy rains in western North America led to a sharp increase in the population of deer mice, which carry hantavirus.
The West Nile virus has entered the United States and is moving northward as the continent warms.
Disease-causing tropical plants have also begun migrating northward. A tropical fungus invaded Vancouver Island in 2002, killing one and injuring 52.
Global warming may also increase the risk of respiratory diseases because grasses and allergenic pollens grow more profusely in a warmer environment. A 2002 study showed that ragweed—a potent allergen producer—grew up to 61 per cent faster under conditions expected by 2050.
Air pollution
According to the Canadian Medical Association, air pollution prematurely kills about 21,000 Canadians a year. Recent studies show that close to eight per cent of all non-traumatic mortality in Canadian cities is attributable to air pollution.
Dangerous one-two punch
Burning fossil fuels is the main cause of both air pollution and climate change, and health experts have concluded that climate change will actually make air pollution an even greater health threat—unless fossil-fuel emissions are drastically reduced.
Studies also show that warmer temperatures drive up pollen counts, which worsen symptoms of allergy sufferers. Researchers have found that increased levels of carbon dioxide not only cause more weeds to grow but also encourage each individual weed to release more pollen.
Ground-level ozone
Ground-level ozone is the nasty cousin of stratospheric ozone. Whereas stratospheric ozone (the “ozone layer”) protects plants and animals from ultraviolet radiation, ground-level ozone is a primary ingredient of smog. Higher temperatures increase ground-level ozone production, thus climate change will intensify urban smog.
Ozone is toxic at low concentrations and deadly at high concentrations. It bursts cell membranes in the lungs, and as cellular fluids build up, breathing becomes more rapid, shallow and painful. The elderly and children are especially vulnerable, and ozone can lead to lifelong damage as lungs stiffen and scar. Ozone also sensitizes the airways to irritants and other allergens. Elevated ozone levels mean more hospital admissions for asthma, respiratory disease and acute respiratory disorders.
Toxic brew
Air pollution from burning fossil fuels produces many other compounds that hurt our health: carbon monoxide, nitrogen oxide, sulphur dioxide, volatile organic compounds and small airborne particulates. They can cause impaired lung function, shortness of breath, wheezing, asthma attacks and premature death.
By reducing our use of coal, oil and natural gas, we can save thousands of lives and lessen the threat to human health of both climate change and air pollution.
