THE 2010
AGGI (Annual Greenhouse Gas Index) reveals that in 2010, despite a continuous growth, HFCs represented only 0.605% of the atmospheric level of greenhouse gases, as communicated by the US NOAA global observing networks. In 2009, their share was 0.58%, and in 2008, 0.55%.
The EFCTC has reported that the figure reveals the high share of radiative forcing results for the 'major gases', accounting for about 96% of the total, while the 15 'minor' halogenated gases contribute the remaining 4%. Major gases include CFC-11 and CFC-12 but exclude all other ODS.
Within the 4% 'minor' gases contribution, HFCs (including HFC-134a, HFC-152a, HFC-125, HFC-143a, and HFC-23) represented 0.605 per cent of all GHG emissions.
The radiative forcing of all GHG increased 29% from 1990 to 2010 (~0.63 W/m2), and CO
2 has accounted for nearly 80% of this increase (~0.50 W/m2). It is thanks to the CFC and HCFC phase out that the global radiative forcing (ability of all greenhouse gases to trap heat) was not as much as 0.3 W/m2 higher in 2010, or more than half of the increase in radiative forcing due to CO
2 alone since 1990.
CO
2 dominates the total forcing with more than 63% of the total and its increase since 1990 was about 39%.
CO
2 and nitrous oxide are the only major gases that continue to increase at a regular rate. Radiative forcing from CH
4 increased from 2007 to 2010 after remaining nearly constant from 1999 to 2006. The decline in the CFCs has tempered the increase in the net radiative forcing considerably. The AGGI is updated annually using global air sample analyses.
The 2010 AGGI (Annual Greenhouse Gas Index) includes atmospheric concentrations of carbon dioxide (CO
2 ), methane (CH
4), nitrous oxide (N
2 O), CFCs 11 and 12, and 15 minor long-lived halogenated gases (CFC-113, CCl
4, CH3CCl
3, HCFCs 22, 141b and 142b, HFCs 134a, 152a, 23, 143a, and 125, SF
6, and Halons 1211, 1301 and 2402).
