Emissions up 41% since 1990, sinks failing
November 19th, 2009 by Jim JustEarth’s carbon dioxide ‘sinks’ are not keeping up with the amount of the greenhouse gas being produced. That’s the conclusion of a paper published in Nature Geoscience:
In the past 50 years, the fraction of CO2 emissions that remains in the atmosphere each year has likely increased, from about 40% to 45%, and models suggest that this trend was caused by a decrease in the uptake of CO2 by the carbon sinks in response to climate change and variability.
Carbon released by fossil fuel burning (black) continues to accumulate in the air (red), oceans (blue), and land (green). The oceans take up roughly a quarter of manmade CO2, but evidence suggests they are now taking up a smaller proportion. Credit: Samar Khatiwala, Lamont-Doherty Earth ObservatoryThe oceans play a key role in regulating climate, absorbing more than a quarter of the carbon dioxide that humans put into the air. The first year-by-year accounting of this mechanism during the industrial era suggests the oceans are not keeping up with rising emissions – a finding with ominous implications for future climate.
The researchers estimate that the oceans last year took up a record 2.3 billion tons of CO2 produced from the burning of fossil fuels. But with overall emissions growing rapidly, the proportion of fossil-fuel emissions absorbed by the oceans since 2000 may have declined by as much as 10%.
The study also found that a 29% rise in carbon emissions between 2000 and 2008 can be attributed to a large extent to burning coal and the growth of ‘emerging economies’. The use of coal as a fuel has now surpassed oil.
Developing countries now emit more greenhouse gases than developed countries – but a quarter of their growth in emissions is from producing stuff for export to developed countries.
In spite of the global economic downturn, emissions increased by 2% during 2008.
The press release summarizes the main findings of the study:
- CO2 emissions from the burning of fossil fuels increased by two per cent from 2007 to 2008, by 29 per cent between 2000 and 2008, and by 41 per cent between 1990 and 2008. 1990 is the reference year of the Kyoto Protocol.
- CO2 emissions from the burning of fossil fuels have increased at an average annual rate of 3.4 per cent between 2000 and 2008, compared with one per cent per year in the 1990s.
- Emissions from land use change have remained almost constant since 2000, but now account for a significantly smaller proportion of total anthropogenic CO2 emissions (20 per cent in 2000 to 12 per cent in 2008).
- The fraction of total CO2 emissions remaining in the atmosphere has likely increased from 40 to 45 per cent since 1959. Models suggest this is due to the response of the natural CO2 sinks to climate change and variability.
- Emissions from coal are now the dominant fossil fuel emission source, surpassing 40 years of oil emission prevalence.
- The financial crisis had a small but discernable impact on emissions growth in 2008 – with a two per cent increase compared with an average 3.6 per cent over the previous seven years. On the basis of projected changes in GDP, emissions for 2009 are expected to fall to their 2007 levels, before increasing again in 2010.
- Emissions from emerging economies such as China and India have more than doubled since 1990 and developing countries now emit more greenhouse gases than developed countries.
- A quarter of the growth in CO2 emissions in developing countries can be accounted for by an increase in international trade of goods and services.