The 2009 AGGI (Annual Greenhouse Gas Index) reveals that in 2009, HFCs represented 0.58 per cent of the atmospheric level of greenhouse gases, as communicated by the US NOAA global observing networks. In 2008, their share was 0.55 per cent.
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, HFCs (including HFC-134a, HFC-152a, HFC-125, HFC-143a, and HFC-23) represented 0.58 percent of all GHG emissions.
The radiative forcing of all GHG increased 27.5% from 1990 to 2009 (~0.60 W/m2), and CO2 contributed considerably to this increase (~0.47 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), would have been as much as 0.3 W/m2 higher in 2010, or more than half of the increase in radiative forcing due to CO2 alone since 1990.
CO2 dominates the total forcing with more than 63% of the total and its increase since 1990 was about 36%. The slowdown in the methane growth rate and the decline in the CFCs have tempered the increase in the net radiative forcing considerably.
CO2 and nitrous oxide are the only major gases that continue to increase at a regular rate. CO2 has accounted for about 80% of this increase in radiative forcing since 1979.
Using global air sample analyses the AGGI is updated annually.
Note : The 2009 AGGI (Annual Greenhouse Gas Index) includes atmospheric concentrations of carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), CFCs 11 and 12, and 15 minor long-lived halogenated gases (CFC-113, CCl4, CH3CCl3, HCFCs 22, 141b and 142b, HFCs 134a, 152a, 23, 143a, and 125, SF6, and Halons 1211, 1301 and 2402).