Carbon Budget Report for 2008
The annual growth of atmospheric CO2 was 1.8 ppm in 2008, slightly below the average for the period 2000-2008 of 1.9 ppm per year (ppm = parts per million). The mean growth rate for the previous 20 years was about 1.5 ppm per year. This increase brought the atmospheric CO2 concentration to 385 ppm in 2008, 38% above the concentration at the start of the industrial revolution (about 280 ppm in 1750). The present concentration is the highest during at least the last 2 million years.