Monday, February 25, 2008

Pending Climate Change

Without question, the summer of 2007 in the high Arctic has shocked the scientific community. Glibly telling each other that the slow visible erosion of the sea ice had decades to play out, they were presented with a fait accompli of massive loss in just one season. It also lacked any particular warning because the surface climate was much as had already been previously experienced.

Now they have had a chance to re - cook their numbers, they are all realizing that sea ice will be possibly gone from the Arctic in the summer anytime toward the end of the next five years. This means during their watch.

Of course there are a few commentators who grasp at the fact that current winter ice has once again reached its normal fullest extent. As my readers know, this is not meaningful. It is all about the major loss of perennial ice throughout the Arctic and no season by itself can seriously change that.

Now that we are seeing the onset of the end game, I want to remind readers that this is all about a very slight increase in the available heat in the Northern Hemisphere for the past forty or so years. We are talking about as little as a half of a degree. However that half degree is sufficient to clear the Arctic Ocean of sea ice in the summer.

Once we are past this ice clearing period after perhaps 2012, then we can expect a climate regime similar to the medieval warm period. I am expecting Northern Europe to warm by several degrees with positive effects on the growing season. We may even see the Greenland permafrost disappear and perhaps the return of dairy farming there.

In other words, there are a lot of microclimates that will go through a protracted adjustment. Most of these will actually be beneficial.

Of course the CO2 enthusiasts have a lot to say, but it is mostly about how the ending of CO2 production will actually matter. I remain extremely skeptical on that one, and am more concerned that this particular idea will lead to truly wrongheaded public policies that we will wear for decades. It also promises to consume resources badly.

There is plenty of evidence to hand telling us that we are dealing with a very natural cycle that has not been disturbed for a long time. In fact, a very good question is to ask what will lower global temperatures a couple of degrees as happened to trigger the little ice age. The cooling cause is vastly more important than the warming.

I posit that left undisturbed, the climate of the Northern Hemisphere will be at least as warm as present. We have the exact long periods of both the medieval warm period lasting a couple of hundred years and the Bronze Age lasting at least a thousand years. These periods were remarkably stable from what we can determine. This was certainly because the Arctic did clear every summer, and even the coldest single winter had little impact.

Yet a sudden drop in global temperatures by at least a couple of degrees whose effect lasted for say ten years would reestablish the perennial sea ice that would then take hundreds of years to overcome.

I have also posited several causation ideas for this cooling. But I must admit that the one type of event really able to do the trick so abruptly is a prolonged major volcanic event. We remember the impact of Krakatau in 1883 on the global climate.

I do not think that the time frames properly match up, or maybe we are just wrong, but if the Thera blast ended the Northern European Bronze Age, it did it by dropping the temperature there by several degrees, precipitating a large movement of peoples into the Mediterranean perhaps already adding to related clans already in place. Recall that the geography of the Iliad maps the Baltic, not the Aegean and these sea peoples immediately populated coastal areas throughout the Mediterranean.

That merely leaves one remaining question. What went bang and ended the medieval warm period? I should also mention that it need not have been a single event.

I would like a global mapping of volcanic events for the past 10,000 years against the tree ring record which is also a fair proxy for climate. A lot of information still needs to be collected there.

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