<blockquote class="twitter-tweet"><p lang="en" dir="ltr">▼▼ CO2 in the atmosphere dropped to 413.69 ppm on February 28, 2020 from 414.12 ppm a year ago ▼▼ Mauna Loa Observatory <a href="https://twitter.com/NOAA?ref_src=twsrc%5Etfw">@NOAA</a> data &amp; graphic: <a href="https://t.co/MZIEphYygh">">ht…</a></p></blockquote>