Climate change refers to any significant change in measures of climate (temperature, precipitation, or wind patterns lasting for decades or longer. Climate change may result from:

• natural factors such as changes in the sun’s intensity or slow changes in the Earth’s orbit around the sun;
• natural processes within the climate system (e.g. changes in ocean circulation);
• and human activities that change the atmosphere’s composition and the land surface.

Some amount of greenhouse gases is necessary for life to exist on Earth. Greenhouse gases trap heat in the atmosphere, keep the planet warm and in a state of equilibrium.

For More Information

• Carbon Dioxide Information Analysis Center
• Clean Air - Cool Planet
• Ecokids - Canad's Environmental Destination for Kids
• EPA - Climate Change Summation
• EPA - Climate Change - What You Can Do
• EPA - Climate Change Kids Site
• Intergovernmental Panel on Climate Change
• Iowa DNR - Greenhouse Gas Emissions
• NASA - Climate for Grownups
• NASA - Climate Kids
• NASA - Goddard Institute for Space Studies
• NASA Studies Aerosols
• NOAA's State of the Climate Report
• Primer on Climate Change Science (July 2011)
• The Climate Registry
• The University Corporation for Atmospheric Research - The Greenhouse Effect