Sunday, October 7, 2012

Tipping Points Considered Dangerous

A while back, discussions of Arctic sea ice, methane, and other related matters seemed dominated by the idea that there was a “tipping point” involved, a point before which we could return to the halcyon equilibria of yore, and after which we were irrevocably committed to a new, unspecified, but clearly disastrous equilibrium.  Surprisingly, this idea was recently revived as the overriding theme of a British Government report assessing trends in Arctic sea ice and their likely effects on the UK itself.  It is cast as a debate between Profs. Slingo of the Met Office and Wadhams, and the report comes out in indirect but clear support of Wadham’s position that these trends are in no sense “business as usual”.  However, it casts this conclusion as the idea that there are “tipping points” in methane emissions, carbon emissions, and sea ice extent, that these are in danger of being crossed, and that once these are crossed the consequences are inevitable and dire – an idea that seems prevalent in national discussions of an emissions “target” of no more than enough tonnage to cause no more than 2 degrees Centigrade warming by 2100.

Here, I’ll pause for a bit of personal reminiscence. My late father-in-law, who was a destroyer captain in WW II, told me that once during the early days of the US’ involvement, during a storm in the North Atlantic, the destroyer heeled over by 35 degrees. Had it heeled over by 1 or 2 more degrees, it would have turned turtle and probably all lives aboard would have been lost. As it was, it righted itself with no casualties. 
That, to me, is a real “tipping point”. The idea is that up to a certain amount of deviation, the tendency is to return to the equilibrium point; beyond that, a new equilibrium results. 35 degrees or less, the ship tends to return to an upright position; beyond that, it tends to go to an upside down position, and stay there.

So what’s wrong with applying the idea of such a tipping point to what’s going on in climate change?  Superficially, at least, it’s a great way to communicate urgency, via the idea that even if it’s not obvious to all that there’s a problem, we are rapidly approaching a point of no return.

Problem One: It Ain’t True

More specifically, if there ever was a “tipping point” in Arctic sea ice, carbon emissions, and methane emissions, we are long past it.  The correct measure of Arctic sea ice trends, now validated by Cryosat, is volume. That has been on an accelerating downward trend just about since estimates began in 1979, clearly driven by global warming, which in turn is clearly driven by human-caused carbon emissions. Carbon emissions themselves have risen in an accelerated fashion from about 1 ppm/year in 1950 at the start of measurements to about 2.1-2.5 ppm/year today. Methane emissions from natural sources (a follow-on to carbon emissions’ effect on rising global temperature) were not clearly a factor until very recently, but it is becoming clear that they have risen a minimum of 20-30% over the last decade, and are accelerating. By way of context, these methane emissions are accompanied by additional carbon emissions beyond those in present models, with the methane emissions being about 3% and the carbon emissions being about 97% of added emissions from such sources as permafrost, but with the methane being 20 to 70 times as potent, for a net effect that is double or triple that of the added carbon emissions alone – an effect that adds (in a far too optimistic forecast) around 0.5 to 1 degree Celsius to previous warming forecasts by 2100.
In other words, it is extremely likely that the idea of keeping global warming to 2 degrees Celsius is toast, even if our carbon atmospheric ppm levels off at around 450.

Problem Two: We Need To Understand It Can Always Get Worse

Yet the idea that we can combat global warming deniers or make things plain to folks reasonably preoccupied with their own problems by saying “we’re on a slippery slope, we’re getting close to a disaster” is that it is all too easily obfuscated or denied, and the sayer labeled as one who “cries wolf.” Rather, we need to communicate the idea of a steadily increasing problem in which doing nothing is bad and doing the wrong thing (in this case, adapting to climate change by using more energy for air conditioning and therefore drilling for more oil and natural gas, increasing emissions) is even worse. This idea is one that all too many voters in democracies find it hard to understand, as they vote to “throw the bums out” when the economy turns bad without being clear about whether the alternative proposal is better.  How’s that working out for you, UK?

The sad fact is that even when things are dreadful, they can always get worse – as Germany found out when it went from depression and a Communist scare to Hitler. It requires that both politicians and voters somehow manage to find better solutions, not just different ones.  For example, in Greece today, it appears (yes, I may be uninformed) that one party that was briefly voted in may well have had a better solution that involved questioning austerity and renegotiating the terms of European support. Two parties committed to doing nothing, and one far right-wing party committed to unspecified changes in government that probably threatened democracy. After failing to give the “good” party enough power in one election, the voters returned power to the two do-nothing parties, with the result that the situation continues to get worse. Now, more than a fifth of voters have gravitated to the far-right party, which would manage to make things yet worse. 

And that is the message that climate change without tipping points is delivering: not that changing our ways is useless because we have failed to avoid a tipping point, but doing the right thing is becoming more urgent because if we do nothing, things will get worse in an accelerating fashion, and if we do the wrong thing, things will get even worse than that.  Tipping point?  One big effort, and it’ll be over one way or another.  Accelerating slide? You pay me now, or you pay me much more later. 

Or Is That Au Revoir?

An old British comedy skit in the revue Beyond the Fringe, a take-off on WW II movies, has one character tell another:  “Perkins, we need a futile gesture at this stage. Pop over to France. Don’t come back.” The other responds: “Then goodbye, sir. Or perhaps it’s au revoir [until we meet again]?” The officer looks at him and simply says “No, Perkins.”

The idea of a tipping point in climate change is like that hope that somehow, some way, things just might return to the good old days. But there is no au revoir.  Say goodbye to tipping points. Say hello to “it can always get worse.” 

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