Atmospheric CO2 levels make huge jump ... or do they?

A Reuters story about startling high levels of carbon dixoide in the air near the North Pole caught my eye this week.

Levels of carbon dioxide, the main greenhouse gas from human activities, rose to 392 parts per million (ppm) in the atmosphere in Svalbard in December....

392?

That seems awfully high, seeing as we're used to reading about 385, or maybe 387 ppm for the last year or so. Should we be switching into panic mode? After all, if CO2 can rise at 8 ppm in one year, that would be a sure sign of a dramatic positive feedback mechanism. The answer is no, at least not because of this one report.

First, for a runaway positive feedback mechanism to have kicked in, such as melting methane-rich permafrost, we'd have to have seen comparably high temperatures. Things are unusually warm up in the Arctic, where global warming is proceeding at least three times faster than the Earth's average, but it turns out that rest of the world isn't experiencing similarly rapid temperature increases.

More importantly, Svalbard may be experiencing CO2 levels that high, but that's not the standard gauge. And it looks like the Svalbard gauge is always higher than elsewhere. Here's the lead to the Reuter's story:

OSLO (Reuters) - Atmospheric levels of the main greenhouse gas are hitting new highs, with no sign yet that the world economic downturn is curbing industrial emissions, a leading scientist said on Thursday. The rise is in line with the long-term trend," Kim Holmen, research director at the Norwegian Polar Institute, said

And here's the lead to a New Scientist story from April 2007:

Greenhouse gases have climbed to record highs in the atmosphere , said Kim Holmen, research director of the Norwegian Polar Institute, which runs the Zeppelin measuring station in Ny-Alesund. Concentrations of carbon dioxide had risen to 390 parts per million from 388 ppm a year ago.

I'm not sure why the Svalbard data attracts attention, especially if Holmen keeps issuing the same press release. CO2 levels aren't going to be exactly the same at every recording station on the Earth. There's altitude and proximity to emissions sources to consider, just to name two. It doesn't really matter where you take the reading, as you don't switch between locations from year to year. Since 1958, most references to atmospheric CO2 levels involve the measurements being taken at the top of Hawai'i's Mauna Loa, largely because Charles Keeling started taking measurements before most anyone else.

There, in the middle of the Pacific, the most recent data, for January 2009, show 386.92 ppm. So call it 387. This is consistent with a yearly increase of about 2 ppm. That's still worrisome, as the previous three decades saw an annual growth rate of only 1.3 or 1.5 ppm, according to the Global Carbon Project.

The acceleration is due to faster-than-expected growth in fossil-fuel emissions. In the 1990s they were growing at less than 1% a year. By 2007, that rate had risen to more 3.5% a year. Those numbers prompted Stephen Schneider, one of the first climatologists to go public with his concerns about rising CO2 levels, to remark:

If this trend continues for the century, "you'd have to be luckier than hell for it just to be bad, as opposed to catastrophic." (USA Today, 9/26/2008)

And unless the economic situation gets significantly worse, we can expect the current growth rate of CO2 to continue for a while, or even accelerate further. This is partly due to the declining capacity of the oceans and other natural sinks to absorb CO2. The Carbon Project talks about an 18% decline in sink efficiency, and worsening. And this explains why climatologists believe it doesn't make sense to wait for new clean-energy technologies to mature before we start reducing carbon emissions. The longer we wait, the less efficient will be the natural sinks, and therefore the larger the gap between where we want atmospheric concentrations of greenhouse gases to be and where they are.

So Barack Obama's new Energy Secretary Stephen Chu might be right when he talked the other day of the need for a technological revolution to avoid a climate crisis, but physicist-blogger Joe Romm's observation that "the time to act is yesterday" seems at least as accurate.