Health Treats from Climate Change

Heat Stroke and Dehydration

Heat waves can lead to heat stroke and dehydration, and are the most common cause of weather-related deaths. Excessive heat is more likely to impact in regions where people are less prepared to cope with excessive temperatures. Young children, older adults, people with medical conditions, and the poor are more vulnerable than others to heat-related illness.

Climate change is likely to yet lead to more frequent, more severe, and longer heat waves in the summer, as well as less severe cold spells in the winter. A recent assessment suggests that increases in heatrelated deaths due to climate change would outweigh decreases in deaths from cold-snaps.

Urban areas are typically warmer than their rural surroundings. Climate change could lead to even warmer temperatures in cities. This would increase the demand for electricity in the summer to run airconditioning, which in turn would increase air pollution and greenhouse gas emissions from power plants. From these, future heat waves could be especially severe in large metropolitan areas.

The annual heat-related deaths in large cities - like Los Angeles in the U.S., for example - are projected to increase two- to seven-fold by the end of the 21st century, depending on the future growth of greenhouse gas emissions. Heat waves are also often accompanied by periods of stagnant air, leading to increases in air pollution and the associated health effects.

Accidents in Extreme Weather Events

The frequency and intensity of extreme precipitation events are projected to increase in certain regions, as is the severity (wind speeds and rain) of tropical storms. These extreme weather events could cause injuries and, in some cases, death. As with heat waves, the people most at risk include young children, older adults, people with medical conditions, and the poor. Extreme events can also indirectly threaten human health in a number of ways. For example, extreme events can:

Reduce the availability of fresh food and water; Interrupt communication, utility, and health care services; Contribute to carbon monoxide poisoning from portable electric generators used during and after storms; Increase stomach and intestinal illness among evacuees; Contribute to mental health impacts such as depression and post-traumatic stress disorder.

Climate-Sensitive Diseases

Changes in climate may enhance the spread of some diseases. Disease- causing agents, called pathogens, can be transmitted through food, water, and animals such as deer, birds, mice, and insects. Climate change could affect all of these transmitters.

Food-borne Diseases

Higher air temperatures can increase cases of salmonella and other bacteria-related food poisoning, because bacteria grow more rapidly in warm environments. These diseases can cause gastrointestinal distress and, in severe cases, death.

Flooding and heavy rainfall can cause overflows from sewage treatment plants into fresh water sources. Overflows could contaminate certain food crops with pathogen-containing feces.

Water-borne Diseases

Heavy rainfall or flooding can increase waterborne parasites such as Giardia and Cryptosporidium that are sometimes found in drinking water. These parasites can cause gastrointestinal distress and in severe cases, death.

Heavy rainfall events cause storm-water runoff that may contaminate water bodies used for recreation (such as lakes and beaches) with other bacteria. The most common illness contracted from contamination at beaches is gastroenteritis, an inflammation of the stomach and the intestines that can cause symptoms such as vomiting, headaches, and fever. Other minor illnesses include ear, eye, nose, and throat infections.

Animal-borne Diseases

Mosquitoes favor warm, wet climates and can spread diseases such as the West Nile virus.

The geographic range of ticks that carry Lyme disease is limited by temperature. As air temperatures rise, the range of these ticks is likely to continue to expand northward. Typical symptoms of Lyme disease include fever, headache, fatigue, and a characteristic skin rash.

In 2002, a new strain of West Nile virus, which can cause serious, life-altering disease, emerged in the United States. This new strain requires higher temperatures to the survive.

The spread of climate-sensitive diseases will depend on both climate and non-climate factors. The risks for these diseases can be much higher in poorer countries that have less capacity to prevent and treat illness.

Other Health Implications

Other connections exist between climate change and human health. For example, changes in temperature and precipitation, as well as droughts and floods, will likely affect agricultural yields and production. In some regions of the world, these effects may compromise food security and threaten human health through malnutrition, the spread of infectious diseases, and food poisoning. The worst of these effects are projected to occur in developing countries, among vulnerable populations. And diseases in affected countries can affect other countries by way of trading, migration and immigration and can even have implications on the national security of these countries.

It is old wisdom that one shall seek to know and accept his own truth and the attitude of the world will matter less to him.

- Another Kind of Love,