Atmospheric carbon the dioxide (CO2) concentration will rise above a narrow threshold this year and be more than 417 parts per million (ppm) – an increase of 50% since the beginning of widespread industrial activity in the 18th century.
The forecast comes from the Met Office, the UK’s national meteorological service, which used data collected at the Mauna Loa Observatory in Hawaii. Although there was a slight decrease in greenhouse gas emissions in 2020 due to the COVID-19 pandemic and the current La Niña Event (a weather pattern in the Pacific that usually lowers global carbon emissions), it was not enough to compensate for previous increases.
“As CO2 stays in the atmosphere for a very long time, the emissions from each year contribute to the previous years and cause the amount of CO2 in the atmosphere to continue to increase,” said Richard Betts, head of the climate impact group at the Met Office and principal investigator for the forecast, said in a statement.
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The concentration of CO2 in the atmosphere follows predictable seasonal variations. The levels peak in May and then decrease during the summer as plants grow across the Northern Hemisphere and absorb carbon (with photosynthesis) before rising again from September.
Although the total amount of CO2 released globally in 2020 has decreased by 7% from previous years, emissions have almost reached pre-pandemic levels again, according to the Met Office.
The current La Niña event, which has caused exceptionally cool weather since mid-2020, is also expected to reduce the increase in CO2 this year. This is due to a temporary increase in the amount of carbon stored in ecosystems such as tropical forests, which grows faster in cooler conditions.
However, it is still not enough to stop the planet from reaching this ominous CO2 milestone.
Rush acceleration
Mauna Loa Observatory maintains the continuous record of atmospheric CO2 concentrations in the world.
Since climate scientist Charles David Keeling started these records in 1958, scientists have been using the data to track atmospheric CO2 levels using the Keeling Curve, a graph that has become an iconic symbol of the growing impact of humanity. on the global climate system.
This means that we have to do a lot of work to achieve the goal of the International Panel on Climate Change to limit global warming 1.5 degrees Celsius (2.7 degrees Fahrenheit) above pre-industrial levels.
“To reverse this trend and slow down atmospheric CO2 rises, global emissions will need to be reduced, and to stop them, global emissions will have to be brought to a net zero,” Betts said. “It should happen within about the next 30 years if global warming is limited to 1.5 degrees Celsius.”
The Met Office has the CO2 forecast for 2021 on January 8th.
Originally published on Live Science.