Established world forests sink carbon equivalent to 33% of carbon world emissions from fossil fuel
Total world established forests sunk 2.4 PgC/yr from 1990-2007 (Yude Pan et al. 2011)
Mean world fossil fuel emissions 1990-1999: 6.4 PgC/yr Mean world fossil fuel emissions 2000-2009: 7.8 PgC/yr [AH math]: (6.4+7.8)/2 = 7.1 Mean world fossil fuel emissions from 1990-2009: 7.1 PgC/yr (C. Le Quéré et al. 2013)
[AH math]: 2.4/7.1 = 33% Established world forests sink carbon equivalent to 33% of carbon world emissions from fossil fuel
established world forests accounted for 3.5 billion ha in 1990 and 3.3 billion ha in 2007 (Yude Pan et al. 2011)
Yude Pan et al., "A Large and Persistent Carbon Sink in the World's Forests," Science 333, no. 988 (2011): 989 and Suplementary material 26 (Table S2), accessed June 9, 2014, doi:10.1126/science.1201609; C. Le Quéré, “The global carbon budget 1959–2011,” Earth System Science Data 5, (2013), 174, accessed June 9, 2014, doi:10.5194/essd-5-165-2013.