The Green House Effect is a natural heating. It occurs when gases in our atmosphere trap heat. Carbon dioxide is the main green house gas.  Without the green house effect life would not be possible because Earth would be too cold. The sun heats the atmosphere and heat energy becomes trapped.  However, today more and more green house gases are being released. These gases trap additional heat causing the Earth to become even warmer. If the Earth gets too warm the polar caps could melt, triggering global flooding in coastline areas.