Monday, May 12, 2008
NOAA data indicates that carbon dioxide concentration in the atmosphere has reached new heights. NOAA greenhouse gas index link CO2 levels in the atmosphere now stand at 387 parts per million (ppm), up 40% since the industrial revolution and the highest levels experienced during the last 650,000 years. The annual mean growth rate for 2007 was over 2.1 ppm. In the 1960s, the growth rate was less than 1 ppm. By the 1980s, the growth rate had increased to 1.5 ppm. But since 2000 the annual rise has increased to an average 2.1ppm. This increasing rate of growth in CO2 concentration may indicate that forests and oceans are no longer effectively absorbing CO2 -- this suggests continuing CO2 emissions will have a greater impact on mean global temperature than predicted by existing climate models – requiring deeper cuts in emissions than those recommended by the IPCC to prevent dangerous levels of global warming.