Our atmosphere contains invisible rings in space which surround the Earth. Sunlight passes through the atmosphere and warms the Earth. The Earth then sends this energy back towards space. Certain gases in the atmosphere absorb some of this energy and this trapped energy keeps the Earth warm and at an even temperature. Due to industry and other man-made causes, the mix of these gases has changed.
Now, more energy is trapped in the atmosphere and the result is the “greenhouse effect”, making the Earth warmer. This could cause the polar ice caps to melt resulting in a rise in sea level. This is a danger to our planet so the United Nations is studying the problem to find ways to control the gases that trap energy.