I recently posted about what methane was up to (Methane checkpoint), prompted by the noticeable upturn in the atmospheric level of that particular greenhouse gas. See that post for sexy graphs and instructions on making your own (graphs, not methane). My conclusion is that there’s definitely something going on with the methane level, but it’s way too soon to know for sure if it’s just another surge, as we’ve seen in the past, or the first sign that the methane time bomb is going off.
Now it’s time to take a look at atmospheric CO2, since there’s now data that something odd is going on there, as well.
The Trends in Carbon Dioxide page on the US NOAA’s Earth System Monitoring Lab’s web site provides the following graph:
Update (July 14, 2009): The graph above is an updated version, so the “rightmost dot” reference to below is no longer accurate.
Look at that last observation–the rightmost dot on the red line–and the black trend line, which take the data up to April of this year. What’s up with that jump, one might well ask (or write about on one’s blog)? And how does this connect with the unnerving but inconclusive methane blip?[1]
An article in Scientific American, The Arctic Thaw Could Make Global Warming Worse, points out:
Methane is emitted anywhere organic matter ferments-be that a cow’s belly or frozen soil that starts to thaw. Permafrost, which averages 80 feet thick, is chock-full of dead plant and animal matter that has been locked in cold storage for thousands of years. Conventional wisdom long held that permafrost should take thousands of years to melt away, so researchers expected it to play a negligible role in climate change. But recent findings-Walter’s lake discovery in particular-have wrecked that prediction.
Walter’s work revealed that the relatively warm lake bed was indeed thawing the frozen earth directly below it, down several dozen feet. Thawing a block of permafrost is like taking a package of frozen hamburger out of the freezer and leaving it on the kitchen counter. As the meat warms, ravenous microbes consume it, giving off a gas as a by-product. On dry land, microbes convert the dead animal and plant matter primarily into CO2. But in the wet, oxygen-starved depths of a lake, they instead release methane. Walter’s best guess is that researchers have been underestimating methane emissions from Arctic wetlands by as much as 63 percent.
(The article above is a fascinating, and more than slightly disturbing, look at the changes climate chaos is triggering at the top of the world, and the potential for a massive feedback from CO2 and methane releases. It also gives a glimpse into the dedication of the scientists who are on the leading edge of this work.)
Suddenly there are unexpected, or unexpectedly large, increases in the atmospheric levels of CO2 and methane, the two signature pieces of empirical evidence we would expect to see in the early stages of the permafrost time bomb going off. But they’re no more definitive than any other unusual short-term data: They’re highly suggestive and they beg to be scrutinized even more closely to determine the underlying causes, but in and of themselves they don’t prove anything.
Given the potential consequences if these numbers do reflect a massive release of these two greenhouse gases due to a permafrost melt, these are trends I really wish we didn’t have to try to explain. But we certainly can’t afford to ignore them and hope they somehow go away; the universe has never been that accommodating.
[1] The data in the graph isn’t much of a sample size. Luckily, the NOAA provides a text file with the monthly global mean readings, linked from the above page, starting in January, 1980. You can grab it directly here. I loaded the “average” column of data from that file into Excel and found that the March-to-April change in 2009 (0.76) is the largest for any March-to-April period in the data. The average increase for the March-to-April transition across all years (except 2009) is 0.41. One can get carried away slicing and dicing data, so we shouldn’t read too much into the 2009 value being so much larger than the average, but at a gross level it does show that something unusual happened.
Excellent page Lou, I wouldn’t have seen all this together without it. Seems like all we can do with “everything” is wait and see where its going. The “hurry up and wait” aspect of so much of this crisis is really starting to grate on my nerves, especially when we get to whether society ending feedback mechanisms are kicking in large scale.
If this is the reaction to all the arctic permafrost starting to melt, it would seem climate change literate people are going to get very desperate, very quickly – I mean good god, we need another 10 or 20 years before this stuff starts in a large scale fashion. We just, really, do not need this at this point.
I wonder how long we’ll have to wait to know for sure? What do you think? 2-3 years?
I remember hearing an author (who wasn’t associated with the geo-engineering field) stating that he thought we’d be forced as a society to seriously entertain geo-engineering strategies (just to keep the temperature brakes on while we get emissions down) in 5-10 years. I thought that sounded far fetched at the time (last year), but here we are a year later and if these trends continue and accelerate as the north continues to warm – we may just end up where he thought we’d be, frightening.
The “hurry up and wait” thing is really eroding me, as well. It’s the knowledge of the potential value of this being the beginning of the climate equivalent of The Big One (meaning a huge California earthquake).
My gut feeling, based on statistical experience with non-climate time series data (mostly from economics) and my E&E reading, is that we could have a pretty good idea much sooner than 2-3 years. Since 1980, the yearly peak in CO2 level has come in April or May every year. If we peaked this year in June, or saw a statistically significant deviation from the established pattern over the summer, then I think the odds of it being the permafrost bomb would go up considerably. I don’t know if that would mean a 10% or 50% or 90% chance of it being The Bomb, but it would certainly set off alarm bells. If the pattern more or less returns to form, but we start seeing a deviation every year, and it gets larger, then it could take several years to be convincing.
I think the odds that we’ll be able to drop emissions quickly enough to avoid betting the farm (and the city and …) on geoengineering are declining. Right now, my gut feeling is that it’s only about a 60 to 70% chance, but that’s making some (very?) optimistic assumptions about international agreements and compliance.