It is often asserted that because deforestation is responsible for 20% of greenhouse gas emissions, it is also responsible for 20% of climate change. The implication is clear: other things being equal, 20% of the world’s climate change mitigation efforts should go toward trying to halt deforestation. However, this argument is not valid. Carbon released from deforestation does not increase the total amount of carbon being exchanged among the atmosphere, the oceans, soils, forests, and so on. Carbon released from fossil fuels, on the other hand, does increase this above-ground carbon pool – adding to the difficulty of keeping excess carbon dioxide out of the atmosphere.