Learn more about global warming.

by MedlinePlus Trusted Health — Information for You A service of the U.S. National Library of Medicine from the National Institutes of HealthNational Institutes of Health

Weather can be hot or cold, dry or wet, calm or stormy, clear or cloudy. Climate is the average weather in a place over a long period of time. Changes in climate may be due to natural forces or from human activities. Today climate changes are happening at an increasingly rapid rate.

Climate change is altering weather and climate patterns that previously have been relatively stable. Climate experts think that climate change will bring increasingly frequent and severe heat waves and extreme weather events, as well as a rise in sea levels. These changes have the potential to affect human health in direct and indirect ways.

* Climate change affects the social and environmental determinants of health – clean air, safe drinking water, sufficient food and secure shelter.
* Global warming that has occurred since the 1970s caused over 140 000 excess deaths annually by the year 2004.
* The direct damage costs to health (i.e. excluding costs in health-determining sectors such as agriculture and water and sanitation), is estimated to be between US$ 2-4 billion/year by 2030.
* Many of the major killers such as diarrhoeal diseases, malnutrition, malaria and dengue are highly climate-sensitive and are expected to worsen as the climate changes.
* Areas with weak health infrastructure – mostly in developing countries – will be the least able to cope without assistance to prepare and respond.
* Reducing emissions of greenhouse gases through better transport, food and energy-use choices can result in improved health.