The Mauna Loa anomaly

World Reports

George Bush is President. That’s the bad news. The good news, at least from the point of view of climate aficionados, is that with Russia’s recent ratification, the Kyoto Protocol is about to enter into force – on Feb 16, to be precise. It’s not the turning point – not yet – but it’s a step, and it might just be enough to take us onto ground that’s firm enough to support another. In fact, if you’re looking for a silver lining in the dark cloud of the recent American election, consider this: with the US under Bush coming out as an open enemy of the climate negotiations (as it just did at December’s climate conference in Buenos Aires) the Europeans and the developing world just might face the fact that they have to go on alone, and try to negotiate a meaningful next-generation climate deal, one that might actually work.

Such is the good news, and such the hope. It will have to do, for hope of some kind is essential when trying to peer into the future. Which, to be absolutely clear, we have no option but to do, and to learn to do well.

Because the future is just about here. And, alas, it’s not looking so good. Take a single datapoint, or rather a recent shift in a venerable data series, a shift that scientists have dubbed the Mauna Loa Anomaly. Take, that is, an unprecedented and still incompletely explained rise in the rate by which the atmospheric carbon dioxide concentration is rising. Take the possibility that we may already, and quite suddenly, be at the brink of runaway global warming.

Mauna Loa is the site of a Hawai’ian observatory which, since 1958, has been measuring the carbon-dioxide concentration of the warm Pacific breezes drifting by its high volcanic hillsides. The term “anomaly” refers to the striking fact that 2002 and 2003 were the first two consecutive years in which the measured carbon-dioxide concentration increased by more than 2 parts per million (ppm).

The term “Mauna Loa Anomaly” is an optimistic one, as in “let’s hope it’s an anomaly.” Let’s hope the rate of increase slows right down!

What researchers have seen is a clear trend in which the carbon-dioxide concentration inexorably rises. The average concentration last year, according the Mauna Loa data, after an increase of 2.08 ppm in 2002 and 2.54 ppm in 2003, was 375.64 ppm. It is a level and a rate of increase which a strengthening scientific consensus indicates is going to be very dangerous indeed. More to the immediate point, the 2002–03 increase cannot be explained by any corresponding jump in terrestrial emissions from power stations and motor vehicles, for the simple reason that there wasn’t one.

It doesn’t look like 2004 is going to mark a third year of greater than 2 ppm concentration increases, though it’ll likely be close. So does this mean that there’s little to worry about? Hardly. Regardless of what happens in 2004, the decadal average increase is decisively up, from 1.3 ppm per year in the early period of the Mauna Loa series to 1.6 ppm in recent decades. Even more worrisome is the fact that previous rate peaks were all associated with El Niño phases in the ocean/atmospheric oscillation (the ENSO oscillation) that causes such significant changes to global weather patterns. This time they were not. Moreover, and decisively, previous peaks – 1988, for example, when the increase was 2.45 ppm, and 1998, when it was 2.74 ppm – were generally followed by troughs, and there’s no indication that another one is coming just now.

There is, according to Dr. Charles Keeling, who initiated and still collects the Mauna Loa data, a “cause for concern.”

“It is possible that this is the beginning of a natural process unprecedented in the record. This could be a weakening of the earth’s carbon sinks, associated with the world warming, as part of a climate change feedback mechanism.”

A cause for concern indeed.

The Mauna Loa Observatory

There isn’t space here to properly explain the details of what the IPCC so genteelly calls “dangerous climate change.” Suffice it to say that we’ve already passed the point where the atmospheric concentration is dangerous. Consider the observed effect: a global drought, killer heatwave, and the melting Arctic for starters – and that we can anticipate much worse before we can hope to get things under control. Under the circumstances, this would be a very bad time indeed for the rate of increase in the atmospheric carbon-dioxide concentration to suddenly speed up.

So what’s actually going on? The jury’s still out, but the drift of expert opinion is that forest fires in the Northern hemisphere – fires that have been particularly bad lately – are spewing massive amounts of carbon into the air. Dr. Peter Cox, head of the carbon cycle group at Britain’s Hadley Centre (and a man to watch for carbon-cycle news), thinks that this is exactly the explanation for the 2002/2003 anomaly:

“My guess is that there were extra forest fires in the northern hemisphere, and particularly a very hot summer in Europe. This led to a dieback in vegetation and an increase in release of carbon from the soil rather than more growing plants taking carbon out of the atmosphere which is usually the case in summer.”

Which raises an interesting question: Assuming that this is the explanation for the recent rate peak, should we take it as good news – after all, the fires are not necessarily signs that global warming is speeding up in some terrible irreversible way – or as bad?

The answer to this question turns on another: What’s the reason for the recent wave of forest fires? This is where the bad news comes in. According to a recent report in Nature, evidence is mounting that global warming may be the deepest cause of the huge wildfires now becoming common in the northern hemisphere. And if this is the case, then we may have already reached a point that wasn’t expected to arrive for decades, a positive feedback point where global warming increases carbon emissions which cause more global warming.

Which takes us back to the British Hadley Center, the climate research center which, by the way, was the real-life model for the small group of heroic scientists who quietly froze to death just after drinking a last bottle of Scotch in the film The Day After Tomorrow. Hadley has been arguing for years now that it’s only a matter of time before global warming causes forests, including, most ominously, tropical forests, to dry and to burn, rapidly changing from “the lungs of the world” into grass and scrub ecosystems that bind significantly less carbon than the forests they’ve replaced.

And this may be exactly what’s now happening, exactly what we see in the sharp up-tick of the Mauna Loa Anomaly. It’ll be a few more years until we know for sure, but one thing is already abundantly clear.

There is “cause for concern.”

What you can do:

Take action: For more information, see Building on Kyoto, a collection of presentations by members of the international Climate Action Network. For a more detailed boil-down of the science, see Honesty About Dangerous Climate Change.

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