CO2, Methane reach record levels in atmosphere worsening climate change

Atmospheric levels of the three main greenhouse gases that are responsible for the global warming – carbon dioxide, methane and nitrous oxide – have all reached new record highs in 2021, according to a new report from the UN’s World Meteorological Organization (WMO). The UN agency’s yearly Greenhouse Gas Bulletin has warned of the biggest annual jump in methane concentrations in 2021 since systematic measurements were started about 40 years ago. The carbon dioxide levels have also increased from 2020 to 2021, which is larger than the average annual growth rate over the last decade.

“[The report] has underlined, once again, the enormous challenge – and the vital necessity – of urgent action to cut greenhouse gas emissions and prevent global temperatures from rising even further in the future,” said WMO Secretary-General Petteri Taalas. According to the report, CO2 concentrations last year reached 415.7 parts per million (ppm), methane 1908 ppm, and nitrous oxide 334.5 ppm. These values constitute, respectively, 149 per cent, 262 per cent and 124 per cent of pre-industrial levels before human activities started disrupting the natural balance of these gases in the atmosphere, mentions UN News.

CO2 from the fossil fuels

The Bulletin explains that after COVID-19 related lockdowns were lifted, global CO2 emissions have rebounded, and the prime sources are fossil fuel and cement production. “Of the total emissions from human activities during the 2011–2020 period, about 48 per cent accumulated in the atmosphere, 26 per cent in the ocean and 29% on land”.

Methane from biogenic sources primarily

Methane is the second largest contributor to climate change. It is a “diverse mix of overlapping sources and sinks, so it is difficult to quantify emissions by source type”, scientists explain. “Since 2007, global methane concentration has been increasing at an accelerating rate. The annual increases in 2020 and 2021 are the largest since systematic registry began in 1983”.

WMO hopes that the science included in this Bulletin, and the State of the Global Climate report will be published in the eve of the UN Climate Conference COP27 in Egypt, and will help in galvanizing negotiators into more ambitious action plan against the climate change.