Climate change: China's forest carbon uptake 'underestimated'
China's aggressive policy of planting trees is likely playing a significant role in tempering its climate impacts.
An international team has identified two areas in the country where the scale of carbon dioxide absorption by new forests has been underestimated.
Taken together, these areas account for a little over 35% of China's entire land carbon "sink", the group says.
The researchers' analysis, based on ground and satellite observations, is reported in Nature journal.
A carbon sink is any reservoir - such as peatlands, or forests - that absorbs more carbon than it releases, thereby lowering the concentration of CO2 in the atmosphere.
China is the world's biggest source of human-produced carbon dioxide, responsible for around 28% of global emissions.
But it recently stated an intention to peak those emissions before 2030 and then to move to carbon neutrality by 2060.
The specifics of how the country would reach these goals is not clear, but it inevitably has to include not only deep cuts in fossil fuel use but ways also to pull carbon out of the atmosphere.
"Achieving China's net-zero target by 2060, recently announced by the Chinese President Xi Jinping, will involve a massive change in energy production and also the growth of sustainable land carbon sinks," said co-author Prof Yi Liu at the Institute of Atmospheric Physics (IAP), Chinese Academy of Sciences, Beijing, China.
"The afforestation activities described in [our Nature] paper will play a role in achieving that target," he told BBC News.
China's increasing leafiness has been evident for some time. Billions of trees have been planted in recent decades, to tackle desertification and soil loss, and to establish vibrant timber and paper industries.
The new study refines estimates for how much CO2 all these extra trees could be taking up as they grow.