February 22, 2010

Rising Sea Level Claims Retracted

A 2009 claim that sea levels would rise up to 32 inches by the end of the century, is being retracted, as the original report's author says the real estimate is still not known.

Scientists have discovered mistakes that undermine the projected sea level increase that would be affected by global warming. The study, published in the journal Nature Geoscience, confirmed the conclusions of a 2007 report from the Intergovernmental Panel on Climate Change. The 2009 study collected data from the previous 22,000 years to predict that sea levels would rise by between 3 and 33 inches by the year 2100.

The IPCC said their estimates placed the sea level to rise to be between 7 and 23 inches, but stressed this was based on incomplete information and that the true rise in sea levels could be even higher.

Scientists have criticized the IPCC for being too conservative in their approach. Several papers have been published suggesting that the sea could rise even more. Martin Vermeer of the Helsinki University of Technology, Finland and Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research in Germany published a paper in December that predicted a rise of up to 75 inches by the end of the century.

Announcing the formal retraction of the paper from the journal, Mark Siddall, from the Earth Sciences Department at the University of Bristol, said: "It's one of those things that happens. People make mistakes and mistakes happen in science." There are two separate mistakes in the paper, which were pointed out by scientists after it had been published. A formal retraction was required, rather than a correction, because the errors undermined the conclusion of the study.

"Science is a complicated game and there are set procedures in place that act as checks and balances," Siddall told the Guardian, adding that retraction is a regular part of the whole publishing process.

It was the first retraction from the Nature Geoscience journal since it was first published in 2007, said publisher Nature Publishing Group.

The paper used fossil coral data and temperature records taken from ice-core measurements to reconstruct how the sea levels have changed with temperature since the last ice age. The paper also projected  how much it could rise with the warming conditions over the several decades. However, the mistakes caused a huge impact on the reliability of the estimates. Authors of the paper said they can no longer draw a sturdy conclusion regarding sea levels in the next 90 years without further research.

The mistakes that undermined the study were miscalculation and not allowing fully for temperature changes over the past 2,000 years. "Because of these issues we have retracted the paper and will now invest in the further work needed to correct these mistakes," the authors said.

Vermeer and Rahmstorf are thanked for bringing to light the issues and errors regarding the paper on rising sea levels, Said Siddall and his colleagues in the Nature Geoscience retraction.


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