Atmospheric CO2 is accelerating upward from decade to decade.
For the past ten years, the average annual rate of increase is 2.07 parts per million (ppm). This rate of increase is more than double the increase in the 1960s.
See the table below.
Decade Total Increase Annual Rate of Increase
2004 – 2013 20.71 ppm 2.07 ppm per year
1994 – 2003 18.70 ppm 1.87 ppm per year
1984 – 1993 14.04 ppm 1.40 ppm per year
1974 – 1983 13.35 ppm 1.34 ppm per year
1964 – 1973 10.69 ppm 1.07 ppm per year
1960 – 1963 3.02 ppm 0.75 ppm per year (4 years only)
the Industrial Revolution in the 19th century, global average CO2 was
about 280 ppm. During the last 800,000 years, CO2 fluctuated between
about 180 ppm during ice ages and 280 ppm during interglacial warm
periods. Today’s rate of increase is more than 100 times faster than the
increase that occurred when the last ice age ended.
~ NOAA Media Release "Carbon Dioxide...Tops 400 ppm" (2013)
Why is the atmospheric concentration of CO2 increasing at an accelerating rate? Research suggests that it is because fossil fuels are being burned at an enhanced rate, the ending of the long-term trend of increasing carbon efficiency of economies, and the ocean's diminishing absorption of CO2 (Canadell et al., 2007).
is calculated by CO2Now using measurements of the concentration of CO2
in the atmosphere (Mauna Loa Observatory) that were made and posted by
the Scripps Institution of Oceanography's CO2 Program.
Canadell, J. G., Quéré, C. L., Raupach, M. R., Field, C. B., Buitenhuis, E. T., Ciais, P., . . . Marland, G. (2007). Contributions to accelerating atmospheric CO₂ growth from economic activity, carbon intensity, and efficiency of natural sinks. Proceedings of the National Academy of Sciences of the United States of America, 104(47), 18866-18870. doi: 10.2307/25450516
CO2Now | Data for atmospheric CO2 (Mauna Loa Observatory)
CO2Now | Global carbon emissions
CO2Now | Annual CO2 concentrations
CO2Now | Global temperature
CO2Now | The Climate Sheet: More "Big Picture" Data
The Conversation | Existential risks to our planetary life-support systems (2013)