Atmospheric carbon dioxide content for March 4 2017 -- 407.46 parts per million
One year ago -- 403.79 ppm
February 2017 -- average 406.42 ppm
February 2016 -- 404.04 ppm
January 2017 was warmest January since 1893
about the writer
jim williams
It’s too soon to tell how much the immigration crackdown is to blame.
