I'm not certain this is caused by #COVID19 but there have only been two years since 1975 when CO2 rose less since the first of the year.

Please don't misunderstand. CO2 still higher today than on same day in any year since 1975. The graph refers to how much CO2 has grown since the first of the year. Here is a visualization of how the graph was produced. Data from NOAA: https://www.esrl.noaa.gov/gmd/ccgg/trends/data.html

I'll update this graph about every week. No promises to be as beautiful as work of @ZLabe.

And if this year turns out to be unprecedented in terms of the seasonal evolution of CO2 (i.e., low growth in concentration), it does NOT imply that it was a "good" thing. But it DOES demonstrate that we humans have the ability to flatten more than one curve.