Scientists who challenged the possibility of catastrophic sea level rise in coming decades have retracted their argument. Mark Siddall, whose paper claimed sea level rise from global warming could not be more than 82 centimeters (32 inches) by 2100 — despite other estimates of up to 1.9 meters — asked for the conclusions published in 2009 in Nature Geoscience to be retracted, accepting corrections from researchers who had made the higher estimates. The Guardian misleadingly presented the news with the headline, “Climate scientists withdraw journal claims of rising sea levels“:
Study claimed in 2009 that sea levels would rise by up to 82cm by the end of century – but the report’s author now says true estimate is still unknown.
If all one read was the introduction, a reader might get the false impression that sea level rise from global warming is in doubt. The misleading Guardian headline was picked up — as per usual — by the Drudge Report and Marc Morano’s conspiracy site Climate Depot. Right-wing bloggers, unsurprisingly, latched on to the headline without any comprehension of the story:
Betsy Newmark: Another global warming claim that has had to be retracted because of problems with the data.
Sammy Benoit: OOPS Never-mind! Climate scientists withdraw IPCC-related article claiming sea is rising.
JammieWearingFool: Another global warming myth comes crashing down. No warming since at least 1995, no melting glaciers and now no rising sea levels.
Jules Crittenden: Warmal scientists are compelled to admit (again) that they don’t know what they’re talking about, retract study that predicted up to a nearly three-foot sea level rise by 2100.
Law professor William A. Jacobson: But now the seas are not going to rise? My dream of a waterfront home is melting away faster than the glaciers.
Caleb Howe: Yet another card removed from the geodesic dome of cards that is AGW hysteria.
However, the retraction instead admits that the paper’s calculations for an upper bound to future sea level rise were incorrect, and sea level rise could be much worse. Siddall’s study, “Constraints on future sea-level rise from past sea-level change,” used paleoclimate reconstructions to predict that sea level rise from global warming would be constrained to between 7 cm and 82 cm (3 to 32 in) by the end of the century, in line with the estimated sea level rise in the 2007 Intergovernmental Panel on Climate Change (IPCC) report, which excluded possible effects from ice sheets.
Unfortunately for the future of human civilization, the best scientific estimates of future sea level rise continue to worsen, as it becomes evident that the Greenland and Antarctic ice sheets are losing mass much more rapidly than estimated before 2007. December’s “Global sea level linked to global temperature,” published by Martin Vermeer of the Helsinki University of Technology, Finland and Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research in Germany in Proceedings of the National Academy of Sciences projects a catastrophic rise of 0.75 to 1.9 m (2.5 to 6 feet) by 2100:
Figure 3: Projection of sea-level rise from 1990 to 2100, based on IPCC temperature projections for three different emission scenarios. The sea-level range projected in the IPCC AR4 for these scenarios are shown for comparison in the bars on the bottom right. Also shown in red is observed sea-level (Vermeer 2009). The estimate from Siddall 2009 that contradicted Vermeer has been retracted.
Over the past twenty years, actual sea level rise has been at the top of estimated limits since the first IPCC report in 1990. By 2200, scientists warn, the oceans could rise by more than three meters, submerging cities like Los Angeles, Amsterdam, St. Petersburg, and lower Manhattan.
The right-wingers promoting this news are ironically supporting RealClimate.org scientists, who blogged about the problems with Siddall’s paper in August, 2009. As WhiskeyFire‘s Thers notes, “This is getting monotonous.”