What is a greenhouse gas?
A greenhouse gas is any gas that traps heat in our atmosphere.
There are four main greenhouse gases that help cause climate change:
Most of these gases happen naturally, but burning fossil fuels for power, transportation, and other industries releases a huge amount of these into the air – thousands of times more than occur naturally. When they build up in our atmosphere, the earth heats up.
References
Environmental Protection Agency: Overview of Greenhouse Gases
NASA: Meet the Greenhouse Gases
Natural Resources Defense Council: Greenhouse Effect 101


