What is the greenhouse effect?
The greenhouse effect is a natural process of our atmosphere. Without it, the average surface temperature of the Earth would be -17 degrees rather than the 15 degrees we currently experience. At these temperatures would not have evolved on Earth in its present form and we probably wouldn't exist!
The greenhouse effect means that the Earth's atmosphere acts like an insulating blanket. Light (short wave) and heat (long wave) energy from the sun pass through the atmosphere quite easily . The sun's energy heats the Earth and it radiates its own energy back into the atmosphere.