<blockquote class="twitter-tweet" data-lang="ja"><p lang="en" dir="ltr">🏆📈🏆 Yesterday—May 11, 2019—was humanity’s FIRST EVER DAY with <a href="https://twitter.com/hashtag/CO2?src=hash&ref_src=twsrc%5Etfw">#CO2</a> in air &gt; 415 ppm at the world famous Mauna Loa Observatory 🏆 </p></blockquote>