On Monday at noon, I went to the Russell Senate Office Building on Capitol Hill to attend a seminar organized by the American Meteorological Society.

The speakers were: David Archer of the University of Chicago and Ralph Keeling of Scripps (son of Charles David Keeling, also of Scripps). In two months, the Keeling curve (started by the father, maintained by the son) turns 50 years old. Probably more than any other graph, the Keeling curve is responsible for convincing people of the reality of CO2 buildup in our atmosphere.

Click on the picture at left to get a full-sized PDF of CO2 data from multiple measuring stations (not just Mauna Loa), all showing the same thing. The concentration varies with the seasons (more CO2 is pulled out during the northern- hemisphere summer; less in the northern winter), but overall the amount of this gas is increasing.


The seminar was titled "Natural CO2 Sinks and their Policy Implications: A Closer Look at Where Current CO2 Levels are Headed, in Historical Context." The two scientists gave an outstanding pair of back-to-back presentations, detailing the enormity of climate change we are now committed to.

The image that stuck most in my mind is this one: measurements of atmospheric oxygen (O2) from Cape Grim, Tasmania (Australia).

If volcanoes were the source of all that CO2 building up in our atmosphere, you would expect oxygen measurements to stay static (or at least not to vary beyond normal seasonal variations: the zig zags). But that's not what researchers have found. Instead, the pattern seen in the graph above is clear: oxygen levels are declining in lock-step with CO2's rise. The reason is simple: when we burn fossil fuels, we oxidize hydrocarbons. We can't burn a fossil fuel without oxygen. Oxygen is consumed by the process, and that oxygen is then paired up with carbon to generate CO2. The process is so simple, but the implications are profound. This graph makes clear that human burning of fossil fuels is the source for atmospheric CO2 rise. This is mankind's fingerprint on global warming.

I might also add that it was cool to run into Michelle Arsenault and Linda Rowan at the seminar.

AMS seminar series.

Labels: CO2, global warming, oxygen