China's CO2 emissions 'substantially over estimated'
China's carbon emissions have been substantially over estimated by international agencies for more than 10 years, according to research co-led by the University of East Anglia.
The revised estimates of China's carbon emissions were produced by an international team of researchers, led by Harvard University, UEA, the Chinese Academy of Sciences and Tsinghua University, in collaboration with 15 other international research institutions.
The team re-evaluated emissions from the burning of fossil fuels and cement production from 1950-2013. They used independently assessed activity data on the amounts of fuels burned and new measurements of emissions factors - the amount of carbon oxidised per unit of fuel consumed - for Chinese coal.
Lead UK researcher Prof Dabo Guan, of UEA's School of International Development, said the key contributor to the new estimates was fuel quality, which for the first time was taken into consideration in establishing emission inventories - something the Intergovernmental Panel on Climate Change (IPCC) and most international data sources had not.
“China is the largest coal consumer in the world, but it burns much lower quality coal, such as brown coal, which has a lower heat value and carbon content compared to the coal burned in the US and Europe,” said Prof Guan.
“China is one of the first countries to conduct a comprehensive survey for its coal qualities and a global effort is required to help other major coal users, such as India and Indonesia, understand their physical coal consumptions as well as the quality of their coal types.
"Our results suggest that Chinese CO2 emissions have been substantially over estimated in recent years. Evaluating progress towards countries' commitments to reduce CO2 emissions depends upon improving the accuracy of annual emissions estimates and reducing related uncertainties. These findings represent progress towards improving estimates of annual global carbon emissions."
'Reduced carbon emission estimates from fossil fuel combustion and cement production in China' was published in Nature last week.