Skipping A Step

Here is a little glimpse of how climate alarmism works.  Check out this article in the NewScientist (I don’t know anything about this particular publication, but my general assumption is that most periodicals use “New” in the context of such a title as a synonym for “socialist.”):

Rather than spreading out evenly across all the oceans, water from melted Antarctic ice sheets will gather around North America and the Indian Ocean. That’s bad news for the US East Coast, which could bear the brunt of one of these oceanic bulges.

It goes on and on with more detail, which sounds really scary:

First, Jerry Mitrovica and colleagues from the University of Toronto in Canada considered the gravitational attraction of the Antarctic ice sheets on the surrounding water, which pulls it towards the South Pole. As the ice sheet melts, this bulge of water dissipates into surrounding oceans along with the meltwater. So while the sea level near Antarctica will fall, sea levels away from the South Pole will rise.

Once the ice melts, the release of pressure could also cause the Antarctic continent to rise by 100 metres. And as the weight of the ice pressing down on the continental shelf is released, the rock will spring back, displacing seawater that will also spread across the oceans.

Redistributing this mass of water could even change the axis of the Earth’s spin. The team estimates that the South Pole will shift by 500 metres towards the west of Antarctica, and the North Pole will shift in the opposite direction. Since the spin of the Earth creates bulges of oceanic water in the regions between the equator and the poles, these bulges will also shift slightly with the changing axis….

The upshot is that the North American continent and the Indian Ocean will experience the greatest changes in sea level – adding 1 or 2 metres to the current estimates. Washington DC sits squarely in this area, meaning it could face a 6.3-metre sea level rise in total. California will also be in the target zone.

Spotting the skipped logic step does not require one to be a climate skeptic.  Anyone familiar with the most recent IPCC report should see it too.  Specifically, the authors simply posit — without even bothering to mention it as an assumption! — that tons of land-based ice (remember, sea ice melting has no effect on sea levels) is going to melt in Antarctica.  But just about everyone, even the alarmists at the IPCC, predict just the opposite, even in 3C per century global warming scenarios.

Why?  Well, for a couple of reasons.  The first is that Antarctica is so cold that several degrees of warming will not bring most of the continent above freezing, even in the summer.  The exception is probably the Antarctic Peninsula, which sticks out north of the rest of the continent and accounts for 2% of the land mass and a much smaller percentage of the total ice pack.

The other reason is that if the world warms, the seas around Antarctica will warm and the models show the warming surrounding seas increasing precipitation on the continent and actually increasing snow pack.  In fact, increases in Antarctic ice pack actually exceed decreases forecast in ice packs around the rest of the world.  The entirety of the IPCC ocean rise scenario is driven by the thermal expansion of water, not net ice melting.

By the way, I presume these guys have their math right, but it seems astonishing to me that the ice mass (or lack of it) could really exert enough gravitational pull to change sea levels in the northern hemisphere by a meter or two.  Gravity is an astonishingly weak force — does this reality check?  I had always thought differences in ocean levels (say for example the fact that the Atlantic and Pacific are not the same height on either side of the Panama Canal)  had more to do with differentials in evaporation rates.

PS- Is telling me global warming will flood Washington DC supposed to make me be against global warming?  Because that sounds pretty good to me. ;=)

  • Mae

    I was very interested in this article and the earlier comments. I am looking for proper scientific debate on the issue not the current farce which is reminiscent of the medieval persecution of Galileo and Bruno. Surely, the claim that the science proposing AGW is settled is a dangerous assertion running counter to all principles of science – and particularly strange given that climate science is still so young. But surely, AGW proponents would not wish to have the “hunter”, who seems incapable of answering criticism without crude ad hominem attacks, on their side. It harms their credibility.

  • hunter

    Mae,
    Jennifer is in celebrtory mood, with the near-at-hand regulation of CO2 by the US Government.
    As Jennifer proves, it has never been about the science for the AGW movement; it has always been about deconstructing our (very successful) technological/industrial culture.