Monday, January 7, 2008

Lorne Gunter and Arctic heat transport

An excellent editorial in the National Post this morning by Lorne Gunter on the Global Warming flap. It is titled 'A warmer Arctic? Blame Mother Nature'.

He makes two telling points. The first is not particularly new, in that he points out that the really good data that we have all been relying on is rather recently gathered. Satellite image image gathering is only 28 years old and our Arctic weather data is only about fifty years old for North America. The second point is that Russian weather data goes back much longer and this tells a very different story.

This editorial was inspired by the recent article in Nature by Rune Graversen and others that takes the position that there is a long atmospheric heat transport cycle that accounts for all the observations. It makes the additional observation that this cycle of heat transport has a long history, hardly news to my readers. In fact it has been the historical record that has motivated my exploration of all heat transfer scenarios. Needless to say, these folks do not support the CO2 causation hypothesis.

The Russian data collected over a century appears to support a scenario in which we have just passed a peak heat period and are now about to enter a prolonged cooling period. Next summer will be a true stress test of what is really happening out there in the Arctic.

The real question is whether the atmospheric heat transport hypothesis is sufficient to explain the historic record, including the recent warming trend. I personally am a little skeptical simply because the heat content of a cubic mile of the Gulf Stream trumps hundreds of cubic miles of warmer air. Of course the exchange mechanisms also matter except that the Arctic is the end of the line for excess heat.

We really have insufficient data to prove either case except to find ourselves blowing in the wind. If we have a sharp reversal in Arctic temperature conditions that is sustained for the next twenty years, then perhaps the atmospheric model will be deemed robust enough.

At the moment we have a purportedly cooler winter throughout North America, although that could merely be an advantageous reorganization of air flows. Right now, California appears to be catching the pineapple express and we are having pleasant weather instead. I think that they needed to top up their reservoirs.

The Russian data, which needs to be more available, paints a picture of long lasting past weather cycles that we cannot ignore and force us to temper our enthusiasm. The current warming trend in the Arctic if sustained for about seven more years will sweep the Arctic clean in the summer and increase solar energy absorption. A reversal now will put that scenario off for decades at least.

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