Comments at Eli's previous post led me to Chris Mooney's fun and games at WaPo, reporting on some law professor talking about how a Harvard researcher showed that melting Greenland will lower regional sea level for places like the Netherlands and therefore it's all great. When pressed skeptically by physicist/Congressman Bill Foster who says the overall effect must be to raise sea level, Prof Rotunda says, "Read his article, that's what he says".
Okay, let's do that! Here is Harvard's Jerry Mitrovica:
When an ice sheet melts, that gravitational influence diminishes, and water moves away from the ice sheet, causing sea levels to drop as far as 2,000 kilometers away. (The drop is most pronounced close to the glacier, because gravity’s effects dissipate with distance.)Vindication! Unless of course the very next sentences tell us something additional:
But because the sea level has fallen where the ice sheet melted, it rises everywhere else beyond that 2,000-kilometer boundary, and on distant shores this rise is far greater than the global average. The effect amplifies the rise in average global sea level attributable to the addition of the meltwater itself to the oceans.
Either Prof. Rotunda had failed to read more than two and one-half paragraphs of an article he discusses in Congressional testimony at some length, or he's being deceptive.
On top of that, three other points. First it's not clear that the 2000 km range is a net effect after considering the effect of increased ocean volume from melt, or just the range of discernible gravitational effect. If the latter, then Rotunda's claim that Netherlands gets a benefit is misplaced in yet another way. The quote is in a mainstream magazine, not peer reviewed. I thought I was being lazy by not finding the original publication, but besides not knowing where it is, I'm not testifying to Congress right now.
Second, Greenland is big. Rotunda seems to think a magical gravity shield protects any place in Europe that's within 2000 km of any place in Greenland from all Greenlandish impacts. If most of the mass loss in Greenland is more than 2k away, it doesn't matter if some of it's closer - the net effect is worse than not considering gravitational effect.
Third, Rotunda needs to pull out a ruler and a map. Google Earth says no part of Netherlands is within 2000km of any part of Greenland's ice cap. I wonder if he did the miles/kilometer mixup, but maybe I'm just giving him too much credit. He says Europe doesn't need to worry about Greenland, but except for Northern UK, Ireland, and part of Scandinavia, no part of Greenland is with the magic distance Rotunda is discussing.