Mockup of 3 large banners hanging off the front of MSU's Renne Library to represent 420, the approximate background concentration of CO2 in the atmosphere in parts per million.
Outdoor CO2 concentrations were higher than 420ppm as of yesterday but will **decrease** as North America leafs out, a seasonal trend Dave Keeling 1st measured in the 1950s. And check out this week's #climateweek offerings @montanastate.bsky.social #keelingcurve #becausephysics #perfecttiming