The Science of Greenhouse Gases: Uncertainties in Sources and Sinks, and Implications for Verification

Abstract

Our present knowledge about the carbon cycle, governing the sources and sinks of the most important anthropogenically influenced greenhouse gas CO2 is still far from satisfactory in the quantitative sense. This statement holds on all scales, from global to local. Therefore, long-term atmospheric measurements, on many locations, are absolutely needed, both to improve our quantitative knowledge of the carbon cycle, and to create a firm verification basis for mitigation measures. Yet, it is an illusion to think that source/sink characterisation by these atmospheric measurements will get to the detail that Kyoto Protocol actions can be surveyed and verified on a national level in the coming years (if ever !). Therefore, a combination of validation (on project basis) and verification (on a continental scale) is proposed. Mitigation measures through mere sink enhancement (afforestation) are at best a temporary solution. Therefore, not much (political) effort should be invested into this option.