China is the biggest carbon emitter in the world, but scientists may have been overestimating its contribution to global carbon emissions for more than 10 years, a study published this week in the journal Nature concluded.
In 2013, for example, the researchers calculated China's carbon emissions to be 14 percent lower than the figures for that year reported by monitoring projects in the U.S. and EU.
"At the beginning of the project we thought that the emissions might be higher" than existing estimates, Zhu Liu, an ecologist at Harvard University in Cambridge, Massachusetts, and lead author of the study, told Nature. "We were very surprised."
The researchers recalculated China's emissions based on an analysis of the coal used as fuel in that country, using data from 4,200 mines. They found that the coal is less carbon-rich, and burns less efficiently, than previous emissions calculations had assumed. Ton for ton, Chinese coal combustion produced as much as 40 percent less emissions than the default value used for calculations by the IPCC, the United Nations's scientific panel on climate change.
"Basically, this is the first time we've applied real measurement of the coal quality on a national scale in China," Liu told The New York Times. "The quality is not as good as developed countries, so if we use the same amount of coal, we overestimate the carbon content of the coal, and so we overestimate the carbon emissions."
As the Times points out, the new estimate does not change calculations of the total carbon accumulation in the atmosphere. But it does call into question the amount of emissions that China is responsible for.
"There is still a lot of work to do," Corinne Le Quéré, director of the Tyndall Centre for Climate Change Research at the University of East Anglia in the U.K., and a co-leader of the Global Carbon Project, an organization that publishes data on global carbon emissions and their sources, said in a statement. The new research suggests China's emissions are 10 percent lower than the most recent publication of the Global Carbon Project suggests.
"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," she said.
Uncommon Knowledge
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Newsweek is committed to challenging conventional wisdom and finding connections in the search for common ground.
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Zoë is a senior writer at Newsweek. She covers science, the environment, and human health. She has written for a ... Read more
