WHY THE WARM UP?
Our planet is surrounded by an "atmosphere" made up of a layer of gases. When the sun rays enter the atmosphere, some of the sun’s heat is trapped by the gases, while the rest
escapes back into space. The trapped heat keeps Earth warm enough to live on. But during the past few years, we have made the air a lot dirtier. This dirty air traps more heat and
makes our planet hotter!