Global growth of carbon dioxide still rising

CSIRO has measured above average growth in carbon dioxide levels in the global atmosphere, despite global attempts to reduce these emissions. The source of the increase is most likely from the burning of fossil fuels – coal, oil and gas.

“The results are concerning because carbon dioxide is the main driver of climate change,” says CSIRO Atmospheric Division chief research scientist Dr Paul Fraser. “I am a little bit surprised that the level is so high without input from forest wildfires.”

Measurements at Cape Grim in Tasmania, Cape Ferguson in Queensland, sub-Antarctic Macquarie Island, Mawson in Antarctica, and the South Pole, show that carbon dioxide over the last two years has increased at near-record levels. The persistent increases measured over such a large region of the Southern Hemisphere ensure that they closely reflect the total global emissions.

These results support findings from the National Oceanic and Atmospheric Administration (NOAA) in the United States. NOAA announced this week that independent data from Mauna Loa in Hawaii showed peak seasonal carbon dioxide levels last year.

The last time growth rates of this magnitude were observed was in 1998 when a huge input of carbon dioxide, attributed by CSIRO to the 1997-98 Indonesian wildfires, caused global levels to jump alarmingly.

Carbon dioxide concentration in the atmosphere has been steadily increasing due to human activities since the Industrial Revolution. It is now higher than it has been for 420,000 years. The difference between 2002-2003 increases and the last large increase in 1998 is that information from other trace gases in the atmosphere (including isotopes, hydrogen, methane and carbon monoxide) show that the source of the increase is most likely from the burning of fossil fuels rather than emissions from oceans, which are the world’s biggest reservoir of carbon dioxide, or fires from burning forests.

Compared to the trend over the last 10 years, when carbon dioxide has increased in the atmosphere by 13.3 billion tonnes per year, both 2002 and 2003 have seen above average global growth rates at 18.7 and 17.1 billion tonnes. Only 1998 had a higher growth rate over the decade of 23 billion tonnes.

The Cape Grim program to monitor and study global atmospheric composition is a joint responsibility of the Bureau of Meteorology and CSIRO, while the CSIRO network is operated in cooperation with the Bureau of Meteorology, the Australian Antarctic Division, Australian Institute of Marine Science, NOAA and other international research agencies.

For more information contact:

Dr Paul Fraser, 03 9239 4613, Mobile: 0413 674 725
Dr Roger Francey, 03 9239 4615

Media assistance:
Simon Torok, 0409 844 302