Record-Breaking Carbon Dioxide Detected In The Atmosphere Last Month


Dr. Alfredo Carpineti

Senior Staff Writer & Space Correspondent

clockApr 8 2021, 16:50 UTC
Industrial Chimney. Image Credit:  Leonid Sorokin/

Industrial Chimney. Image Credit:  Leonid Sorokin/

The latest measurements of atmospheric carbon dioxide show that humanity has broken another grim record of the climate crisis. On average, March had 50 percent more carbon dioxide in the air than before the Industrial Revolution.

Despite lower emissions in 2020, the increase is remarkable. The concentration of carbon dioxide in the air varies month by month, peaking around May. Last May, researchers from the Scripps Institution of Oceanography measured 417.1 parts per million (ppm) of CO2 in the air. Crossing for the first time 417 ppm threshold equivalent to a 50 percent increase compared to the average value between 1750 and 1800.


Now, March 2021 has crossed that even further, recording on average 417.14 ppm for the month. The human-released carbon dioxide is on course to peak at 419.5 ± 0.6 ppm in May as was predicted a few months ago. This will continue the huge increase in the average concentration that has been witnessed in previous years. The Met Office predicts that the level of CO2 will be around 2.29 ppm higher in 2021 than in 2020.

"Even during the COVID-19 pandemic we have still been emitting CO2 and this is increasing the amount of the greenhouse gas held in the atmosphere. Since pre-industrial times we have increased CO2 in the atmosphere by about 50 percent and this has led to 1.2°C global warming. If we are to meet the Paris Agreement and keep global warming well below 2°C we have our work cut out for us. Rapid and substantial CO2 emissions reductions are needed to avoid the worst climate change impacts," Dr Andrew King, a Climate Researcher from the University of Melbourne not involved in the measurement, said in a statement.

The concentration of carbon dioxide in the atmosphere is measured daily, with a variation much greater than it is seen in month-to-month and year-to-year measurements. The National Oceanic and Atmospheric Administration have reported the first-ever daily measurement above 420 ppm. On  April 3 this year, the CO2 concentration at their measuring station was 421.21 ppm.


"There is no surprise that we keep breaking atmospheric CO2 records given we are emitting globally in the vicinity of 40 billion tonnes of CO2 every year. The impacts of COVID-19 on the economy have resulted in a reduction in emissions, 2.5 billion tonnes less in 2020, to be precise, but CO2 will continue to accumulate in the atmosphere and break new records until the day we no longer produce emissions," Dr Pep Canadell, CSIRO Research Scientist, and Executive Director of the Global Carbon Project, also not involved in the measurement, explained in a comment