Updated: 01-11-2022
Source: WMO
WMO records biggest increase in methane concentrations since start of measurements
Geneva/New York, 26 October (WMO) - In yet another ominous climate change warning, atmospheric levels of the three main greenhouse gases - carbon dioxide, methane and nitrous oxide all reached new record highs in 2021, according to a new report from the World Meteorological Organization (WMO).
WMO’s Greenhouse Gas Bulletin reported the biggest year-on-year jump in methane concentrations in 2021 since systematic measurements began nearly 40 years ago. The reason for this exceptional increase is not clear, but seems to be a result of both biological and human-induced processes.
The increase in carbon dioxide levels from 2020 to 2021 was larger than the average annual growth rate over the last decade. Measurements from WMO’s Global Atmosphere Watch network stations show that these levels continues to rise in 2022 over the whole globe.
Between 1990 and 2021, the warming effect on our climate (known as radiative forcing) by long-lived greenhouse gases rose by nearly 50%, with carbon dioxide accounting for about 80% of this increase.
Carbon dioxide concentrations in 2021 were 415.7 parts per million (ppm), methane at 1908 parts per billion (ppb) and nitrous oxide at 334.5 ppb. These values constitute, respectively, 149%, 262% and 124% of pre-industrial levels before human activities started disrupting natural equilibrium of these gases in the atmosphere.
“WMO’s Greenhouse Gas Bulletin has underlined, once again, the enormous challenge – and the vital necessity – of urgent action to cut greenhouse gas emissions and prevent global temperatures rising even further in the future,” said WMO Secretary-General Prof. Petteri Taalas.
CH4 annual increase
“The continuing rise in concentrations of the main heat-trapping gases, including the record acceleration in methane levels, shows that we are heading in the wrong direction,” he said.
“There are cost-effective strategies available to tackle methane emissions, especially from the fossil fuel sector, and we should implement these without delay. However, methane has a relatively short lifetime of less than 10 years and so its impact on climate is reversible. As the top and most urgent priority, we have to slash carbon dioxide emissions which are the main driver of climate change and associated extreme weather, and which will affect climate for thousands of years through polar ice loss, ocean warming and sea level rise,” said Prof. Taalas.
“We need to transform our industrial, energy and transport systems and whole way of life. The needed changes are economically affordable and technically possible. Time is running out,” said Prof. Taalas.
WMO UN Climate Change conference, COP27, in Egypt from 7-18 November. On the eve of the conference in Sharm-el-Sheikh it will present its provisional State of the Global Climate 2022 report, which will show how greenhouse gases continue to drive climate change and extreme weather. The years from 2015 to 2021 were the seven warmest on record.
The WMO reports seek to galvanize COP27 negotiators into more ambitious action decision makers to achieve the Paris Agreement goal to limit global warming to well below 2, preferably to 1.5 degrees Celsius, compared to pre-industrial levels. The average global temperature is now more than 1.1°C above the 1850–1900 pre-industrial average.
Given the need to strengthen the greenhouse gas information basis for decisions on climate mitigation efforts, WMO is working with the broader greenhouse gas community to develop a framework for sustained, internationally coordinated global greenhouse gas monitoring, including observing network design and international exchange and use of the resulting observations. It will engage with the broader scientific and international community, in particular regarding land surface and ocean observation and modelling.
WMO measures atmospheric concentrations of greenhouse gases – what remains in the atmosphere after gases are absorbed by sinks like the ocean and biosphere. This is not the same as emissions.
A separate and complementary Emissions Gap Report by UN Environment will be released on 27 October. The Emissions Gap report assesses the latest scientific studies on current and estimated future greenhouse gas emissions. This difference between “where we are likely to be and where we need to be” is known as the emissions gap.
As long as emissions continue, global temperature will continue to rise. Given the long life of CO2, the temperature level already observed will persist for decades even if emissions are rapidly reduced to net zero.
Source: WMO
Editor: Liu Shuqiao