Apparently, the warmists can’t wait for this… so they have to cheat.
May 10 Comment: NOAA has reported 400.03 for yesterday, but Scripps has reported 399.73. The difference is similar to other differences we have reported. The difference partly reflects time zone differences. NOAA uses UTC, whereas we use local time in Hawaii to define the start and stop of a given day. Changing to UTC excludes the lower CO2 period from the baseline on the May 9, shifting it to May 10.
The remaining baseline data then averages 400.08 for May 9.
I’ve been retired quite a while now, but I distinctly remembering attending Air Pollution Control Association conferences back in the 80″s where they were reporting that the pre-industrial revolution CO2 levels were 315 ppm and the 1998 levels were about 380 ppm. Now they’re saying 400 ppm? According to a story in today’s Wall Street, It seems that the lower goal post as well as the upper goal post have changed. When did they change their minds? What was it that made them change the so called baseline data?
We should not give a pass to the validity of the so-called Keeling curve. First of all, it is not much of a curve. There is no hockey stick shape to it and little evidence that it is accelerating as always claimed. Thus it does not correlate meaningfully with the increase in human activity’s contribution as input to the atmosphere. Secondly, Mauna Loa is just one small spot on the surface of the earth, a spot on an island which has seen an enormous increase in human-derived CO2 output as economic growth during the same years the the Keeling curve has been in existence. This growth, which included enormously increased auto and air traffic as well as cement production (for construction of many luxury hotels among other phenomena) but must be entered in the equation as a confounding factor of unknown but possibly significant importance, despite the high altitude of the observatory and the atmospheric flux that it is subject to. Thirdly, the millions of years of supposedly lower CO2 levels are proxies from ice core bubbles which have numerous interpretive hurdles of their own and cannot be simply patched backward to the first Keeling data point. Finally, it should be remembered that Keeling (now deceased) elevated the importance of his own data by ignoring previous measures of atmospheric CO2, some of which were well above 400 ppm.
This is perhaps the most trivial part of the climate debate. The 400 mark is arbitrary and the day when it happens is inconsequential.