International team of researchers has compiled and verified newly available data on the country's carbon dioxide reduction, and, for the first time, they have quantitatively estimated the effect of China's carbon mitigation efforts.
Previously, the carbon dioxide monitoring stations on the ground over China were few and far between, resulting in carbon dioxide flux estimates with large uncertainties. One monitoring station could represent a significant area that included distinctly different land use types. The lack of data resulted in fewer studies on carbon emissions in China, as well.
In this study by the international team of researcher, published in Nature, the team found that, between 2010 and 2016, China reabsorbed about 45 percent of the country's estimated annual human-made carbon dioxide emissions.
“China is currently one of the world's major emitters of carbon dioxide, but China's forest resources have been growing continuously for the past 30 years,” said paper author Liu Yi, professor with the Institute of Atmospheric Physics at the Chinese Academy of Sciences. “In this study, we achieve a better understanding of carbon dioxide fluxes over China.”
“Therein lies the crux of the challenge faced by science and policy communities: effective mitigation of fossil fuel carbon dioxide emissions within a large-scale dynamic natural carbon cycle that we do not quantitatively understand," Professor Liu added
Since 2009, the China Meteorological Administration began collecting weekly and hourly continuous atmospheric carbon dioxide measurements, making available data between 2009 and 2016 for the researchers.
“Without good data, it was nearly impossible to assess how China's forestry efforts to mitigate carbon dioxide emissions were actually faring,” commented Wang Jing, lead author of the study from the same institute.
They corroborated that data with independent satellite remote-sensing measurements of vegetation greenness, soil water availability, satellite column observations of carbon dioxide and forest censuses.
“While our results still have large uncertainties, it's clear that China's forest ecosystem has a huge carbon sequestration effect,” said paper author Paul I. Palmer from the School of GeoSciences at the University of Edinburgh in the UK.
The researchers plan to fine tune their results with more ground and satellite data, with the ultimate goal of improving their calculation methods to be able to determine the carbon budget of smaller areas.