Apply MODIS Products to Analyze the Changing Carbon Sink of Beijing before and after Olympics

Beijing honored its promise of a Green Olympics. Determining how the vegetation cover and carbon sink changed before and after Beijing Olympics is the main objective. The land cover data and net primary production (NPP) data from 2001 to 2010 from MODIS product were used. Through the method of average carbon sink efficiency, we get the following result. From 2001 to 2007, the carbon sink is gradually reducing. In 2008, it suddenly rises then keeps stable. The average forest carbon sink of Beijing between 2001 and 2010 is 136 kt, while average forest carbon sink between 2008 and 2010 is 159 kt. The average overall carbon sink of Beijing between 2001 and 2010 is 260 kt, and 277 kt between 2008 and 2010. The reducing carbon sink from 2001 to 2007 has a linear relationship with the reducing vegetation coverage. In 2008, the sudden rise of carbon sink on one hand has something to do with the increased vegetation coverage and transformation of forest from young to grown-up. But mostly it may be a result of the macro-control by the government as importing big trees into the city. MODIS product somewhat captures this change feature which matches reality that demonstrates its practical value.