Climate Kahani | Methane concentration in atmosphere | In a very worrying development, atmospheric levels of the three main greenhouse gases – carbon dioxide, methane and nitrous oxide – reached record levels in 2021, according to a new report by the World Meteorological Organization (WMO).
The WMO’s Greenhouse Gas Bulletin reported the biggest year-on-year jump in methane concentration in 2021.
Biggest surge in the last 40 years
The atmospheric concentration of gases has been measured for the past forty years and this surge is the biggest in the last 40 years. The reason for this extraordinary increase is unclear, but it appears to be the result of both biological and human-induced processes.
Increase in carbon dioxide levels
The increase in carbon dioxide levels from 2020 to 2021 was higher than the average annual growth rate of the previous decade. And now, data from WMO’s Global Atmosphere Watch Network stations show that these levels continue to rise around the world in 2022 as well.
The warming effect on our climate by long-lived greenhouse gases increased by almost 50% between 1990 and 2021. About 80% of this increase was due to carbon dioxide.
Carbon dioxide concentrations in 2021 were 415.7 parts per million (ppm), methane at 1908 parts per billion (ppb) and nitrous oxide 334.5 ppb. These figures are 149%, 262% and 124%, respectively, relative to pre-industrial levels.
Giving his response, WMO General Secretary Prof. “WMO’s Greenhouse Gas Bulletin, once again, underscores the enormous challenge – and critical need – of urgent action to cut greenhouse gas emissions and prevent global temperatures from rising even further,” said Petrie Talas.
“The continued increase in the concentration of gases trapping core warming temperatures, coupled with record-breaking increases in methane levels, suggests that we are headed in the wrong direction,” he added.
Explaining the solution to the problem, he says, “There are cost-effective strategies available to tackle methane emissions in the fossil fuel sector, and we should implement them without delay. However, methane has a relatively short life span of less than 10 years and Therefore its effect on climate can be reversed. As a top and most urgent priority, we must reduce the carbon dioxide emissions that are the main drivers of climate change and related extreme weather, and which are generated by thousands of people through polar ice loss, ocean warming and sea level rise. Will affect the climate for years.”
Highlights of the Bulletin
carbon dioxide (CO2)
Atmospheric carbon dioxide will reach 149% of pre-industrial levels in 2021. Its emissions are mainly due to emissions from fossil fuel combustion and cement production. Global emissions have jumped again in 2020 since the COVID-related lockdowns. Of the total emissions from human activities during the period 2011-2020, about 48% is still in the atmosphere, 26% in the ocean and 29% on land.
Scientists also worry that the ability of land ecosystems and oceans to act as a “carbon sink” may become less effective in the future. This may reduce their ability to absorb carbon dioxide and work against temperature rise.
Atmospheric methane is the second largest contributor to climate change, but emissions by its source and type are difficult to measure.
Since 2007, the average atmospheric methane concentration globally has been increasing rapidly. The annual increase in 2020 and 2021 has been the highest since the beginning of systematic recording of gases in 1983.
The causes are still being investigated by the global greenhouse gas science community. The analysis indicates that the largest contributor to the renewed increase in methane since 2007 comes from biogenic sources. It is not yet possible to say that the extreme growth in 2020 to 2021 is the result of a climate response.
Nitrous Oxide (N2O)
Nitrous oxide is the third most important greenhouse gas. It is emitted into the atmosphere from both natural sources (about 57%) and anthropogenic sources (about 43%), including oceans, soils, biomass burning, fertilizer use and various industrial processes. The growth from 2020 to 2021 was slightly higher than that seen from 2019 to 2020 and was higher than the average annual growth rate over the past 10 years.