Courtesy: Nature and the authors.
Advertisement
According to a paper published by Nature on Wednesday, organizations like the EU’s Emissions Database for Global Atmospheric Research (EDGAR) have overestimated China’s emissions by as much as 14 percent by using inappropriate default conversion rates, Reuters reported.
“For most of the developed countries, coal has been comprehensively washed but in China the process is not so comprehensive”, study lead author Zhu Liu, of Harvard University, told BBC News.
Mr. Xi promised previous year that China’s emissions of carbon dioxide would stop growing by about 2030.
Atmospheric carbon dioxide concentrations have continued rising globally, and the study doesn’t address how its results square with those increasing carbon emissions, Trenberth said.
“The main difference in our paper is for the first time we have taken fuel quality into consideration, which is missing from other estimates”, Guan said.
“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”, says professor Guan.
However, Guan cautioned that the analysis “does not prove that the IPCC is wrong”, while the report states that “estimates of Chinese emissions remain subject to large uncertainty”. However, emission factors for Chinese coal were on average 40 per cent lower than the default levels recommended by the IPCC. China produces more than half of global production of steel and cement.
Other researchers disagree. They say that the new study, while giving greater accuracy about China, doesn’t change the overall global total on emissions. Corinne Le Quéré, director of the Tyndall Center for Climate Change Research at UEA.
Previous calculations were based on Chinese data that lumped lots of different types of coal together, which global agencies then used in a formula known as a unified emission factor.
“There is still a lot of work to do”, said Prof Le Quéré. The strong message here is that as we refine our estimates of carbon emissions we get closer to an accurate picture of what is going on and we can improve our climate projections and better inform policy on climate change..
“Reduced carbon emission estimates from fossil fuel combustion and cement production in China” is published in Nature on August 20, 2015. They used independently assessed activity data on the amounts of fuels burned and new measurements of emissions factors for Chinese coal.
While China used 10 percent more energy between 2000 and 2012 than the country’s national statistics claim, the fossil fuels it burned may have emitted 40 percent fewer emissions than those previously estimated by the Intergovernmental Panel on Climate Change, the study concludes.
But whatever you think of China’s ambitions, the lower estimate of past emissions won’t make fulfilling them any easier.
China’s drive for economic growth over the past 15 years has seen the rapid expansion of coal burning for the production of energy.
China, which overtook the U.S.as the world’s largest emitter of carbon dioxide in 2007 – and has retained the notorious distinction ever since – still relies largely on coal for its domestic energy needs.
However, this new study looked at the actual carbon content found in over 4,000 coal mines in China and in lab tests of 602 coal samples.
Roughly 70 percent of China’s total greenhouse gas emissions come from coal, far more than in the United States or the European Union.
Advertisement
From 2000 to 2013, the country produced almost three billion tons less carbon than previously thought.
