June 5th, 2020 by Roy W. Spencer, Ph. D.
The Mauna Loa atmospheric CO2 concentration data continue to show no reduction in the rate of rise due to the recent global economic slowdown. This demonstrates how difficult it is to reduce global CO2 emissions without causing a major disruption to the global economy and exacerbation of poverty.
After removal of the strong seasonal cycle in Mauna Loa CO2 data, and a first order estimate of the CO2 influence of El Nino and La Nina activity (ENSO), the May 2020 update shows no indication of a reduction in the rate of rise in the last few months, when the reduction in economic activity should have shown up.
I had previously explained why the slowdown would likely not be large enough to affect measured atmospheric CO2 levels compared to natural variations in global sources and sinks of CO2. I calculated that the Energy Information Administration-estimated 11% reductions in CO2 emissions during 2020 would have to be four times larger to stop the rise of atmospheric CO2 over 2019 values (assuming no substantial natural variations in CO2 sources and sinks).