Atmospheric carbon dioxide continues to increase

Update, May 14: You can read Climate Central's take on why this is an important measure here.

Two weeks ago I wrote a post about the Keeling Curve, which measures the concentration of carbon dioxide in the atmosphere and explains why that's important. If you're wondering why NOAA reported that the Earth had, on Friday, the threshold level of 400ppm of carbon dioxide in the atmosphere, but the Scripps Institute of Oceanography  did not, there's a simple explanation - time zones. As a note on the Scripps site puts it:

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.

399.73 or 400.03 - both are bad. There's a good roundup of this and other climate news on the blog "Scrapbook of a Climate Hawk," here.

Global Warming Measurements, now on Twitter

 

Here's another way of looking at climate change: measuring the carbon dioxide (CO2) in the air. And that's what the Mauna Loa record, which has been kept since the late 1950s, does. It's also known as the Keeling Curve, after Charles David Keeling, who set up the program and directed it for many years. 

Keeler was one of the first climate scientists to discover that the earth might behave with surprising regularity (given the right scale), and the long-term effort to measure atmospheric CO2 grew out of that insight. 

The value of the Mauna Loa record soon became readily apparent. Within just a year or two, Charles David Keeling had shown that CO₂ underwent a regular seasonal cycle, reflecting the seasonal growth and decay of land plants in the northern hemisphere, as well as a regular long-term rise driven by the burning of fossil-fuels.

There's some fascinating history at the website of the Scripps Institute of Oceanography here, which was Keeling's academic home. And now Scripps is posting the daily Keeling Curve on Twitter. You can follow it here. What does it mean? Atmospheric carbon dioxide has been increasing steadily. You can see the measure is approaching 400 ppm - a threshold that will mean a different climate. You can read more here.