think-progress:Global Carbon Dioxide Levels Just Hit A Disturbing New ThresholdFour hundred: it’s a
think-progress:Global Carbon Dioxide Levels Just Hit A Disturbing New ThresholdFour hundred: it’s a number that will go down in climate history while also continuing to rise. According to the National Oceanic and Atmospheric Administration (NOAA), 400.83 parts per million (ppm) was the average concentration of atmospheric carbon dioxide in March. This news from NOAA marks the first time that the entire planet has surpassed the 400 ppm benchmark for an entire month. -- source link