What is Global Warming?
Global warming is the increase in the temperature of the earth's atmosphere due to higher than normal levels of greenhouse gases. These greenhouse gases, mainly carbon dioxide, trap the sun's energy in the atmosphere by absorbing some of the energy that would otherwise be released back into space.
The 'greenhouse effect', as this phenomenon is called, is actually essential to all life on Earth. Without it, temperatures would vary drastically, killing all living things on the planet. However, if the effect is too extreme, then too much heat is stored, and this would also affect life. It is widely recognized that global warming is occuring, though there are many theories as to what causes it and how its effects will be seen.