Global warming is a natural process that keeps the planet warm and hospitable for living organisms.
Greenhouse gases are in the earth's atmosphere .
In both cases, light is absorbed as heat. Earth's surfaces, warmed both by solar radiation and by warmth from deep within the earth, radiate heat into the atmosphere, where some is absorbed and some passes out into deep space. The enhanced greenhouse effect occurs when more heat is absorbed by the atmosphere, due to increased greenhouse gases, than can pass by convection into space in a normal manner. A diagram illustrating the process of the greenhouse effect. Click on it to see a full-size version that you can print out.