New data published by the Scripps Institution of Oceanography shows that the concentration of CO2 in the atmosphere has reached a record monthly high of 417 parts per million (ppm). This two ppm change since last May’s reading is in line with the average annual increase. While many predictions strongly suggested that behavior changes due to COVID-19 would affect the atmosphere, temporary shutdowns and slowdowns haven’t been enough to meaningfully decrease the amount of greenhouse gas still present in the atmosphere.
Richard Betts, head of Climate Impacts at the United Kingdom’s national weather service, told New Scientist that he’s not surprised. “The analogy I use is filling a bath from a tap. The water from the tap is the emissions and the water level in the bath is the concentrations. We’re still putting CO2 into the atmosphere, it’s just building up slightly less fast than before. What we need to do is turn the tap off.”
By all accounts, pollution is down. According to NASA, nitrogen dioxide levels between New York and Washington, DC were down about 30% in March, compared to the average for the last five years. Earlier this year, figures published by CarbonBrief showed that the shutdowns associated with COVID-19 in China led to a 25 percent drop in carbon emissions. Photos from cities like Los Angeles, Moscow and New Delhi show smog-free skies over streets emptied by local shelter-in-place decrees. But in order to make a significant change to the CO2 concentration, those emissions would need to drop by 20 to 30 percent over the course of a year, according to the Scripps team.