Ice, Ice Baby

A decent article on the melting of the Greenland ice sheet.

The changes seen in Greenland may turn out to be self-limiting in the short run; surging glaciers can flatten out and slow, for instance. Or they may be a sign that the island’s ice — holding about the same volume of water as the Gulf of Mexico — is poised for a rapid discharge. Scientists are divided on that question, and on whether there is a near-term risk from a Texas-size portion of West Antarctica’s ice sheet that is also showing signs of instability. This split divides those foreseeing a rise in the sea level of a couple of feet this century from water added by Greenland, West Antarctica and mountain glaciers, and a few experts who speak of a couple of yards in that time.

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“It’s basically a big lump of ice sitting on this bedrock,” Dr. Alley said in describing Greenland’s behavior in warm conditions. “What it tries to do is snow more in the middle and melt more on the edges. If it pulls its edges back, then there’s less area to melt, and that helps it survive. That’s why you can have a stable ice sheet in a warmer climate.”

There has been a flack lately about the Arctic surface ice, with one side suggesting that record amount has melted and it's a sign of global warming and another side pointing out that there was also a record refreeze so it doesn't' matter. This neatly sidesteps the actual science, but gives folks something to fight about. In reality the amount of surface area that melts is largely irrelevant, its the *volume* of ice that's significant, a measure neither side has any good data on.

It seems pretty clear that the climate is changing, although it's far from clear exactly why or what can be done about it. Historically, it seems to be changing fairly swiftly as these things are measured (usually in thousands of years), but we have no real written records of a major planetary climate change, so although humanity has lived through this before, civilization has not. It's tempting to blame CO2 emissions and, doubtless they have a part, but CO2 isn't a huge contributor to warming, at least compared to other gasses like CH4, so its a good bet there are other processes going on.

In the end, there may not be a lot we can do about this.

The current state of climatology is similar to the state of early 20th century medicine. It's science but on a complicated organism we don't understand and until recently we just shrugged and prayed to sky-father about it. It's my hopes that advances in atmospheric physics and computer modeling will give us a much better idea of how this whole thing is linked up and what, if anything, we could do to make it better. At this point, almost anything we do is effectively random and may or may not have an effect and certainly it wouldn't have the effect we think it will.

Give science some more time with this.