In a Business 'As usual senario,' global CO2 emissions reach 64 GtCO2 y -1 by 2050. Convert this figure to GtC y-1, and calculate the percentage increase from the level of global CO2 emissions in 2004, estimated as 8.8 GtC y-1.
Lets see...
carbon is what percent of CO2?
12/44 * 100 or 27.3 percent.
So 64 GtCO2 y -1 becomes 64*.273 GtC/y