If global warming is to be limited to 1.5°C, the carbon dioxide being released into the atmosphere must drop by 20% in the next five years.
That’s according to a new report from the Met Office, which has revealed the amount of carbon in the air must come to a halt before the mid-century for any chance of keeping the Paris aims alive.
The study reveals that when first measurements were taken on carbon levels in 1958, the annual rise of carbon dioxide in the atmosphere was one part per million (ppm) and the concentration of carbon was 316ppm.
During the last decade, the annual rise has more than doubled to 2.5ppm, with the overall concentration level reaching an average of 416ppm in 2021.
The study alludes to the IPCC report’s claims that maintaining course for 1.5°C would mean cutting this to 2ppm each year, which is 20% less than last year’s annual rise.
The report also accepts that nature can also have an influence on the rate of rise due to carbon sinks but says this is all the more reason to crack down on human-induced global warming, as it will give time for nature to level out before 2050.
This year, nature is expected to do some of the work to mitigate carbon, with ecosystems such as tropical forests expected to take more carbon dioxide from the atmosphere than usual – but the Met Office warns this should not be seen as a free pass.
Lead author Professor Richard Betts commented: “If the world is to meet ambitious targets within the Paris Agreement, the long-term build-up of carbon dioxide in the atmosphere needs to slow rapidly and come to a halt before mid-century.
“This would need an immediate slowing in the rate that human-induced carbon-dioxide emissions are added to the atmosphere, leading rapidly to a complete stop. A temporary boost from nature is obviously welcome, but we won’t get this free dividend in most years.”