CNN: Cutting down trees is pretty much one of the worst things you can do when it comes to climate change. Deforestation, by varying accounts, contributes anywhere from 20 percent to 30 percent of all carbon dioxide (C02) emissions — around 1.6 billion tons. When you cut down trees you get a double whammy. First of all, they are not called the lungs of the Earth for nothing — we clearly need trees so that we and other animals can breathe. Trees also are in the front line against …