While the concentration of greenhouse gases continued to increase in China and across the world in 2022, the China Meteorological Administration has reported that the increase in terrestrial carbon dioxide levels dropped below the average of the past decade.

The agency’s 2022 annual report — its 12th consecutive study — was released last week. It noted that the China Global Atmosphere Watch Baseline Observatory on Mount Waliguan in the northwestern Qinghai province recorded an approximate increase of 2.3 parts per million from 2021, which aligned with the global increment rate.

The CMA report also noted an increase in concentrations of methane, which has a greenhouse gas effect 28 times stronger than carbon dioxide. The rise was approximately 14 parts per billion in 2021, but marginally below the global increase of 16 parts per billion.

In its Nov. 15 greenhouse gases bulletin, the World Meteorological Organization reported that global atmospheric greenhouse gas levels hit record highs in 2022. For the first time, carbon dioxide concentrations were 50% higher than pre-industrial levels. 

However, the growth rate slightly decreased compared to the previous year and the decade’s average, with the WMO attributing this trend to short-term natural variations in the carbon cycle.

Despite the slight decrease, Zhang Xingying, deputy head of the Department of Science & Technology and Climate Change at the CMA, cautioned at a press conference: “The slowdown in carbon dioxide growth is a positive sign for humanity. However, this alone does not support the claim of a reduction in human emissions.”

Zhang explained that carbon dioxide, as a long-lasting greenhouse gas, can persist in the atmosphere for centuries. Atmospheric carbon dioxide levels are influenced by both the sources of emissions and natural processes of absorption and release. For instance, oceans and forests play a significant role in absorbing and storing carbon dioxide.

He also underscored that the recent succession of La Niña events has substantially enhanced oceans’ capacity to absorb carbon dioxide. This suggests that natural factors are likely contributing to the recent slowdown in the rise of carbon dioxide concentrations.

Starting in 2020, for the first time this century, the Northern Hemisphere has seen three consecutive La Niña winters. In stark contrast to the El Niño phenomenon, La Niña, characterized by cooler-than-normal ocean surface temperatures in the Pacific Ocean, can lead to temporary global cooling. 

Research has shown that El Niño events, with their associated high temperatures and droughts, can impact tropical regions and rainforests, resulting in increased greenhouse gas emissions.

In November, the CMA issued a warning about the formation of a medium-intensity El Niño event, which is expected to persist until next spring. This phenomenon is likely to result in temperatures across most of China being at or above typical levels for this time of year, heightening the risk of climate-related disasters.

Zhang stated on this development, “An El Niño year will, in principle, reduce the ocean’s ability to absorb carbon dioxide. If this holds true, we can anticipate a rise in incremental carbon dioxide concentrations in 2023.”

Editor: Apurva.

(Header image: IC)