The proportion of greenhouse gases in the atmosphere increased last year, although there were temporarily fewer emissions due to the coronavirus pandemic, according to a report by the World Weather Organization WMO. The economic slowdown had no discernible effects on the atmospheric level of greenhouse gases and their growth rates. The share of greenhouse gases reached a new high in 2020 and the trend will continue this year.
If the rate of increase in greenhouse gas concentrations continues, the global average temperature will be well above the goals of the Paris Agreement of 1.5 to 2 ° C above pre-industrial levels, said WMO General Secretary Petteri Taalas. “We are far from the course,” he warned of the upcoming climate conference, which takes place in Glasgow in a week’s time.
The increase in CO2 from 2019 to 2020 to 413.2 ppm was somewhat lower than that from 2018 to 2019, but greater than the average annual growth rate over the past ten years, according to the WMO report (PDF). Last year, the CO2– Fossil fuel emissions down approximately 5.6 percent due to COVID-19 restrictions. The CO2-Concentration reached 149 percent of the pre-industrial level last year. Methane is 262 percent and N2O 123 percent above the level of 1750.
Warm like it hasn’t been for millions of years
About half of the CO2, which is emitted today by human activities, remains in the atmosphere, the other half is taken up by oceans and ecosystems on land, explains the WMO. Due to climate change, these could in future serve less effectively as carbon dioxide sinks and as a buffer against a major rise in temperature. Given the long lifespan of CO2 the current temperature level will last for several decades, even if emissions are quickly reduced to zero.
Based on figures from the Global Atmosphere Watch monitoring network, the new WMO report shows that from 1990 to 2020 radiation pressure – the warming effect on the climate – increased by 47 percent due to long-lived greenhouse gases. CO2 is responsible for about 80 percent. The last time the earth had a comparable CO2Concentration was 3 million to 5 million years ago. At that time the temperature was 2 to 3 ° C warmer than today, the sea level was 10 to 20 m higher. “But back then there weren’t 7.8 billion people,” Taalas said.