What is the amount of CO2 added to the earth's atmosphere each year from fossil fuels?

1 answer

Do you want the net increase per year (which has been measured for about a century) or the amount actually added by fossil fuel combustion? Not all of the CO2 added remains in the atmosphere.

You will find information on both at
http://en.wikipedia.org/wiki/Carbon_dioxide

The amount actually in the atmosphere increases by about 2 ppm per year, which is about about 0.5% . CO2 is currently 388 parts per million (ppm). The total amount in the atmosphere increases by about 1.6*10^13 kg per year. The amount added by human activty is estimated to be 2.7*10^13 kg/year. Some of that gets stored in the ocean.