Climate change, also known as global warming, is the gradual rise in Earth’s temperature. Climatologists generally attribute these changes to man-made emissions of carbon dioxide and other greenhouse gases that have accompanied economic development since the Industrial Revolution. Climate change affects many social and environmental factors that determine human health, including air quality, drinking water, food supplies, and shelter. Therefore, changes in health patterns and diseases can be expected to occur around the world in the future.
It has been clear for some time that sea levels rise, glaciers melt, and weather patterns change. Extreme weather events, such as hurricanes and floods, are becoming more common. Scientists estimate that during the 21st century, the average surface temperature of the Earth’s surface will rise by at least 2 degrees Celsius (about 3.6 degrees Fahrenheit), compared to pre-industrial temperatures, with higher rises likely to occur in high-latitude areas such as northern Canada, Greenland and Siberia. While there may be some benefits arising from warmer climates, such as fewer winter deaths and increased food production, the overall impact of climate change on human health is likely to be extremely negative.
There are various possible health consequences of climate change. These include the direct effects of natural weather-related disasters, such as the destruction of houses and contamination of water supplies. There is also the possibility of changes in the geographical range and season of transmission of insects, which will increase cases of vector-borne diseases, such as malaria.
It is difficult to predict the exact impact of climate change on human health. All populations will probably be affected to some extent. However, some will be more vulnerable than others, and this is where prevention and support efforts should be targeted. These groups include people living in coastal areas, in very large cities, and in mountainous or polar areas. Children, especially those in low-income countries, will be particularly at risk. The elderly, and those with pre-existing medical conditions, will also be more at risk for the damaging impacts of climate change. Finally, people living in countries where health infrastructure is weak will be less able to respond to and cope with the impacts of climate change on their populations.
Overall, those living in poor countries, which have contributed the least to global warming but have less access to resources to deal with its problems, are likely to bear the brunt in terms of health. However, no country will be immune to the impacts of climate change; Extreme weather events such as Hurricane Katrina in 2005 have affected the United States, and heat waves have caused thousands of deaths in Europe.
There are plans to reduce the level of global warming and reduce its impact at the international, national and local levels. These efforts are focused on reducing the amount of greenhouse gases entering the atmosphere. Many countries have also strengthened their defenses against natural disasters and implemented contingency plans. There are many approaches, from developing fossil fuel alternatives to persuading individuals not to rely too much on their cars.
In 2009, scientists at the University College of London Institute for Global Health, writing in a special issue of the medical journal The Lancet, stated “Climate change is the biggest threat to global health.” They noted that both health care professionals and the public remain largely unaware of what climate change will do to public health around the world. More action is urgently needed in the areas of advocacy, research and preparedness planning.