Deforestation and Carbon Uptake

The removal of forests by human action is probably one of the greatest forces in global environmental change and biodiversity loss on our planet. Forests are cleared, degraded and fragmented by timber harvest, conversion to agriculture, road-building, human-caused fire, and in many other ways. The effort to use and subdue the forest has been a constant theme in the transformation of the earth, in many societies, in many lands, and at most times. Deforestation has important implications for life on this planet. Originally, almost half of the United States, three-quarters of Canada, almost all of Europe, and much of the rest of the world were forested. The forests have been mostly removed for fuel, building materials and to clear land for farming. The removal of our forests can contribute as much as 90% of the current net release of biotin carbon dioxide in the atmosphere. The clearing of the forests has been one of the most historic feats of humanity. It is known that photosynthesis consumes about 120 gigatons of atmospheric carbon in the form of carbon dioxide, every year. Photosynthesis is harmed greatly when deforestation occurs. Photosynthesizing biota represent a pool of around 560 gigatons of carbon. 156 gigatons of carbon were released to the atmosphere as a result of land clearance between 1850 and 2000. This gives us an estimate of how many of the photosynthesizing biota were removed due to deforestation. Given the current rate of carbon emission due to modern land clearance processes of 2.3 gigatons per annum, this would leave about 540 gigatons of carbon pooled in photosynthesizing biota at the turn of the century. The carbon pooled by photosynthesizing biota in 1850 would have been closer to 696 gigatons, and thus deforestation represents the removal of 22% of photosynthesis from the carbon budget since 1850.