400 ppm

Another CO2 Milestone

May 22, 2018 By EarthWise Leave a Comment

The global concentration of carbon dioxide in the atmosphere was measured at 400 parts per million for the first time in recorded history in May of 2013. It was a brief event at the Mauna Loa Observatory in Hawaii at the time. Within the next couple of years, however, readings of at least 400 ppm became standard.

Carbon Dioxide Continues To Rise

November 7, 2016 By WAMC WEB

Back in December of 2013, a little less than three years ago, Earth Wise reported that the observatory on Mauna Loa in Hawaii had briefly measured carbon dioxide levels greater than 400 parts per million for the first time ever. During the following year, readings above the 400 level started to pop up occasionally elsewhere as well.

400 ppm

WAMC Northeast Public Radio