So we’ve reached 400 ppm.… Now what happens?
Some aspects of CO2 analysis require old-school methods
Readers may have noticed that the daily average baseline value for May 13, which was originally reported on May 14 as “Too Variable”, was subsequently changed on May 15 to a value of 400.17 parts per million (ppm).
May 10 Comment: NOAA has reported 400.03 for May 9, 2013, while Scripps has reported 399.73. The difference partly reflects
The farther north a CO2 reading is made, the wider it swings with the seasons