Josie Taylor | October 27, 2020
Heat-trapping greenhouse gases in the atmosphere reached a new record last year, with the annual rate of increase above the 2011-2020 average. That trend has continued in 2021, according to the World Meteorological Organization (WMO) Greenhouse Gas Bulletin.
As long as emissions continue, global temperature will continue to rise. CO2 has a long life, therefore the temperature level already observed will persist for several decades even if emissions are rapidly reduced to net zero. Rising temperatures is not the only thing that these emissions will cause. This also means more weather extremes like intense heat and rainfall, ice melt, sea-level rise and ocean acidification. All of these extremes also have socioeconomic impacts.
Roughly half of the CO2 emitted by human activities today remains in the atmosphere. The other half is taken up by oceans and land ecosystems. The Bulletin flagged concern that the ability of land ecosystems and oceans to act as “sinks” may become less effective in future. This means that more of the CO2 will go into the atmosphere and temperatures will increase at an even higher rate.
Carbon dioxide is the most important greenhouse gas in the atmosphere, accounting for approximately ⅔ of climate change effects, mainly because of fossil fuel combustion and cement production.