As climate change scientists develop ever more sophisticated climate models to project an expected path of temperature change, it is becoming increasingly important to include the effects of aerosols on clouds. That's because aerosols, fine particles such as smoke and dust that form droplets in clouds and change cloud thickness, affect how much sun is able to pass through the cloud to Earth, as well as the amount of moisture that's returned to Earth. Both moisture and sunlight play significant roles in climate change.

URL: http://earthobservatory.nasa.gov/Newsroom/MediaAlerts/2007/2007021724329.html