In following up on the World Climate Report (Pat Michaels’ sute) article comparing 1936 to 2010
a couple of folks have hastened to provide anomaly maps of 1936 and 2010 on the same scale. Sure enough, they are not exactly identical. (Click for better images) Surely the author of the article ought to have done as much. In fact, it isn;t difficult to produce comparable anomaly maps here as contributor NewYork points out.
I’m not sure how compelling this all is either way.
What I find even less compelling is the argument on the WCR site from telconnection indices. That just restates the problem; it doesn’t resolve it. And then there is this:
There are several things of note:
1) The July 2010 combined value is the highest since 1950—nearly 50% greater than the second highest value which occurred in 1952.
2) The combined index has been mostly positive since 1981, and mostly negative from 1955 through 1980. This behavior imparts an overall positive trend since 1950.
3) The 2010 value is about 3 times greater than the value expected based on the trend alone.
Is anthropogenic global warming behind any of this behavior?
It is hard to know for sure, but one thing that is certain is that if global warming does have a hand in the game (perhaps through the trend term), what it’s holding is pretty weak.
The argument seems to be that since this year is so far off the trend line, that the anomaly cannot possibly be caused by the same “thing” that caused the trend. One would expect a sounder argument from a professional, but I am seeing versions of this all over the place. The system is nonlinear. There are thresholds, and regime shifts. “Tipping points” if you will. The current year is so anomalous in so many ways that it demands explanation. The fact that it is off the trend line is no secret. The idea that its strangeness cannot possibly be because of anthropogenic forcing since the trend itself has been modest simply doesn’t hold water.
Examples in mundane life? How about blowing up a balloon? The more pressure you put into the balloon, the larger it gets. Up to a point. Then the balance of forces shifts, and it finds a new equilibrium, in shreds all over the room.
This reminds me of the argument that n-g made about the fraction of the Nashville flood (the earlier one, remember?) attributable to anthropogenic change. I simply don’t think these linear arguments stand. There are reasons to anticipate new configurations of the atmosphere during the rapid shifts we have now initiated. It’s not reasonable to assume that it’s just business as usual plus a gentle additive trend in all variables. It may turn out that way (one can hope) but you can’t assume it. And on the evidence of this year, that mild scenario is not the one that is going to play out.
To be fair, the WCR article didn’t really commit to this argument, but it seemed to me to wave in that general direction. A lot of the people who think we are not in very deep trouble seem to have a small-perturbation view of anthropogenic climate change. But it’s only a small perturbation until it ain’t, and nobody really knows when nonlinear adjustments cut in. The simulation models seem unexcitable on this front, but how much do we trust the simulations outside the realm of observational experience?