Greenhouse Effect

CAUSES

Certain gases in the atmosphere--known as greenhouse gases--tend to trap the sun's heat. Some important greenhouse gases, such as carbon dioxide, are building up in the atmosphere as a result of human activities. Major sources of greenhouse gases include the burning of fossil fuels (gas, oil, and coal), forest destruction, and agriculture. Those gases actually stays in the earth atmosphere and forms a blanket, thus, preventing excess heat from reflecting back to space. This is one of the many reasons for the increase in the earth temperature.

PHOTO: Vehicles produce a large share of our greenhouse gas emissions. Cars and trucks that get more miles per gallon can help reduce the risk of global warming.

PHOTO: Rapid population growth and the increasing use of energy per person both contribute to the worldwide rise in greenhouse gas emissions.