The measurement of the CO2 emitted by different human activities is done on a different basis. It is done with:
- the quantity of fuels used
- the carbon content of the used fuels
- the determination of the carbon which has not been combusted (in soot and ashes).
Other sources of CO2 other than fossil fuel combustion are also taken into account:
- process CO2 in the industry
- deforestation, etc...
The roughly 30% difference between both (measured emitted CO2 by human activities and increased CO2 in the atmosphere) points out at an increased CO2 absorbtion by the oceans. This is confirmed by the acidification of oceans. Oceans however tend to absorb less and less CO2. The isotopes of carbon in the atmosphere and in fossil fuels are also studied to verify the carbon cycle and the increased carbon in the atmospheric carbon cycle.
As CO2 is a proven greenhouse gas, an increased concentration of CO2 will increase the greenhouse effect. This increased greenhouse effect will increase (and is already increasing) temperatures.
Germann: you don%26#039;t understand the difference between the %26quot;short cycle%26quot; and %26quot;long cycle%26quot; of carbon, do you?
Did it occur to anybody to calculate additional CO2 produced by increased human population? In or around 1900 the total population of Earth was around 1,650,000,000 (ave) now it is 6,625,000,000 (in mid 2007). To me that makes additional 5,000,000,000 humans inhaling air and exhaling more CO2 24 hours per day, 365 days per year. I did some rough calculations and the CO2 exhaled by %26quot;new%26quot; (since 1900) population gave me an equivalent of CO2 emissions of 500,000,000 cars (that is 500 million).
My guess that the only reason all governments are keeping quite about that is because they can not (yet) tax us for living and breathing, but they can tax us for using fuels...