On April 28, 2020 at 00:58, davidcasemore said...
That's because the chart is taking measurements in the middle of the Pacific Ocean. Give it awhile to catch up.
For a more immediate observation check out the air quality changes from January until today in Mexico City, Los Angeles, New Delhi etc.
I will give it another month to see if it has not fallen with decreased fossil fuel use from planes , cars, machinery, etc. I am sure the cities are better without the CO. and NO. I know of no observation stations that measure the CO2 in LA. You have a link?