WELCOME TO GREEN DSequestering CarbonThe basic idea of sequestering carbon by planting trees is very simple. Trees take incarbon dioxide from the air, and they convert it (along with other elements from the soil and the air) into wood. The amount of carbon sequestered by a tree in a given year is simply the increase of the mass of the tree in a year, multiplied by the fraction of the mass of the tree that is carbon. The chemical composition of wood varies depending on the type of tree, but a good approximation for most types of wood is 50% carbon, 44% oxygen, 6% hydrogen, and trace amounts of various metal ions (see Petterson, USDA,http://www.fpl.fs.fed.us/documnts/pdf1984/pette84a.pdf). Since the atomic weight of carbon is 12, oxygen is 16, and hydrogen is 2, this means that about 42% of the mass of a tree is carbon. There is a netcarbon sequestration only while the forest is growing – once the forest reaches maturity, as trees die they emit the carbon they sequestered back into the atmosphere. In steady state, a mature forest gives off as much carbon as it gathers. Our approach will give credit only for the amount of carbon a tree sequesters per year. You contribute to Bo-Dog Carbon Lock Up (BD CLU) to plant trees, and we give you credit for all the carbon the tree will sequester for your desired term. This approach is justified by the fact that carbon dioxide persists in the atmosphere for several hundred years, so what is important is not how much carbon the tree will sequester immediately, but rather how much it will sequester over and extended period.  To estimate the amount of carbon sequestered, we used the tables provided in the United States Department of Energy document "Technical Guidelines for Voluntary Reporting of Greenhouse Gas Program", March 2006, (http://www.eia.doe.gov/oiaf/1605/Forestryappendix[1].pdf). To compute the carbon offset, it is first necessary to decide on the period of time you want. Estimates for the amount of carbon sequestered after 100 years range from about 75 metric tons/hectare for southwestern Ponderosa pine to about 200 metric tons/hectare for Northeastern oak/hickory. Under the assumption that available water and type of tree are the most important factors. According to the tables, this type of forest fixes about 130metric tons of carbon per hectare over a hundred-year period. Note that we are neglecting the fact that carbon sequestration is not linear, and that we are simply taking an average over the hundred-year period. To see that this estimate makes sense, recall that a hectare is 100 meters by 100 meters, and a metric ton is 100 kilograms. Imagine a mature cottonwood bosque with trees on a grid at intervals of 5 meters. (Of course, BD CLU will not plant the trees on a grid, but we are just making an estimate!). This would correspond to 400 mature trees, with roughly three hundred kilograms of carbon in each tree. Since roughly 42% of the mass of a tree is carbon, this corresponds to each