Global emissions of carbon dioxide dropped by 1.3% in 2009 compared with the previous year, largely due to the effects of the economic crisis and an overall fall in GDP, according to an international team of scientists.
The drop is smaller than the 2.8% fall predicted by many experts for 2009, because the reductions in carbon emissions per unit of GDP — a measure of efficiency called the carbon intensity — was smaller than expected in many emerging economies.
The results are part of the annual carbon budget update by the Global Carbon Project (GCP), an international group of climate scientists and analysts that collates emissions data to help policy makers. The project totalled the carbon emissions due to use of fossil fuels in power stations, cement manufacture and changes in land use, such as deforestation.
Despite the 1.3% overall drop, the 2009 global fossil fuel emissions — 30.8bn tons of CO2 — were the second highest in human history, just below the all-time high of 2008.
The small overall decrease in global emissions masks some big regional shifts, according to the report published on Sunday in Nature Geoscience. As the global financial crisis has mainly affected developed nations, this is where emissions dropped by the largest amounts: in the U.S. by 6.9%, the U.K. by 8.6%, Germany by 7%, Japan by 11.8%, Russia by 8.4% and Australia by 0.4%.
In the emerging markets, however, there were big increases: China rose by 8%, India by 6.2% and South Korea by 1.4%.
The GCP also found that global CO2 emissions associated with deforestation have dropped by 25% since 2000 mainly due to a reduction in tropical deforestation.
“CO2 emissions from fossil fuels are projected to increase by more than 3% in 2010 if economic growth proceeds as expected, approaching the high emissions growth rates observed from 2000 to 2008,” said Pep Canadell, a scientist at the Commonwealth Scientific and Industrial Research Organisation in Australia and executive director of GCP.
Computer models predict that if emissions continue to rise at the present rate, average temperatures are likely to increase by 4 degree Celsius by 2100.