New reports showed that the growth rate in carbon dioxide concentrations was lower than the average of the past decade both for China and globally, with experts attributing the decrease potentially to reduced emissions and more absorption by the ocean.
Data from an observatory in Qinghai province showed that carbon dioxide concentrations in the air in China last year increased at a significantly lower rate than the average annual global increase between 2013 and 2022, the China Meteorological Administration said on Friday.
The 2022 China Greenhouse Gas Monitoring Report, released by the administration on Friday, indicated that the average carbon dioxide concentration increased last year by about 2.3 parts per million, lower than the 2.46 ppm global average increase for the past decade.
The average annual increase in China between 2013 and 2022 was 2.16 ppm.
The China Global Atmosphere Watch Baseline Observatory on Mount Waliguan in Qinghai recorded carbon dioxide concentrations of about 419 ppm last year, roughly the same as the average concentration in mid-latitude regions of the northern hemisphere.
The 12th annual report also indicated that average methane concentrations in China rose by about 14 parts per billion last year, less than the global average increase of 16 ppb.
The administration said it had coordinated greenhouse gas monitoring efforts in regional areas to fulfill China's commitment to reducing greenhouse gas emissions and mitigating climate change.
The WMO's bulletin released in November said that last year global carbon dioxide concentrations are 50 percent higher than pre-industrial levels.
However, the growth rate was slightly lower than the average of both the previous year and the past decade.
The bulletin added that the growth rate of carbon dioxide emissions can be varied by changes in nature.
Zhang Xingying, deputy head of the CMA's Science, Technology and Climate Change Department, told a news conference on Friday that carbon dioxide concentration in the air is determined by emissions sources and natural carbon sinks, including vast oceans and forests that can absorb and store carbon dioxide.
"Either of them can play a role. Also, studies have shown that La Nina events over the past few years have significantly increased the ocean's ability to absorb carbon dioxide," he said.
La Nina describes the cooling of surface-ocean waters along the tropical west coast of South America.
Its opposite, El Nino, is a naturally occurring climate phenomenon that starts with unusually warm surface water in the central and eastern equatorial Pacific Ocean.
"This year is an El Nino year and is supposed to weaken the ocean's ability to absorb carbon dioxide. If it holds, the increase in carbon dioxide in 2023 is likely to increase," Zhang said.