Peter Kenny
25 October 2021•Update: 26 October 2021
GENEVA
The abundance of heat-trapping greenhouse gases in the atmosphere once again reached a new record last year, with the annual rate rising above the 2011-2020 average, the World Meteorological Organization (WMO) said Monday.
At a news conference in Geneva, the WMO released the Greenhouse Gas Bulletin and continued the upward trend in greenhouse gases of this year.
WMO said it contains a stark, scientific message for climate change negotiators at COP26.
“We are way off track,” WMO Secretary-General Petteri Taalas told journalists. “At the current rate of increase in greenhouse gas concentrations, we will see a temperature increase by the end of this century far in excess of the Paris Agreement targets of 1.5 to 2 degrees Celsius above pre-industrial levels.”
The concentration of carbon dioxide (CO2), the most important greenhouse gas, reached 413.2 parts per million in 2020 and is 149% of the pre-industrial level.
“The amount of CO2 in the atmosphere breached the milestone of 400 parts per million in 2015. And just five years later, it exceeded 413 ppm,” said Taalas.
“It has major negative repercussions for our daily lives and well-being, for the state of our planet, and for the future of our children and grandchildren,” said the WMO chief.
CO2 stays in atmosphere for centuries
He explained that carbon dioxide remains in the atmosphere for centuries and in the ocean for even longer.
“The last time the Earth experienced a comparable concentration of CO2 was 3-5 million years ago when the temperature was 2-3°C warmer, and sea level was 10-20 meters higher than now. But there weren’t 7.8 billion people then,” said Taalas.
Methane (CH4) is 262% and nitrous oxide (N2O) is 123% of the levels in 1750 when human activities started disrupting Earth’s natural equilibrium, said the WMO.
The economic slowdown from COVID-19 did not have any discernible impact on the atmospheric levels of greenhouse gases and their growth rates, although there was a temporary decline in new emissions.
“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 several decades even if emissions are rapidly reduced to net zero,” said the report.
The report flagged concern that the ability of land ecosystems, such as parts of the Brazilian rain forests and oceans, to act as “sinks” may become less effective in the future.
Those ecosystems thus reduce their ability to absorb carbon dioxide and act as a buffer against more significant temperature increases.
Alongside rising temperatures, this means more weather extremes including intense heat and rainfall, ice melt, sea-level rise, and ocean acidification, accompanied by far-reaching socioeconomic impacts.
About half of the CO2 emitted by human activities today remains in the atmosphere, said the report.
