Caution: New Sea Level Story May be a Step too Far
April 21, 2016
Above, James Hansen’s recent statement to me re sea level rise.
No one is more deeply concerned about SLR than Hansen, and he has ventured some of the largest numbers we’ve seen for what the potential might be. He does tell us that those numbers rest on certain assumptions:
“..Our record of precise knowledge of the changes in the mass of the ice sheets is rather short, it really began with the gravity satellite, which now has a record of only 12 years, but over that period the mass loss has increased rapidly …if it continues to double at the rate that it has in the last decade, then we could get, within 50 years, meter scale sea level rise, and you’d rapidly, within another one or 2 decades, get multimeter sea level rise. So that’s an enormous threat.”
So, multimeter sea level rise possible if his calculations are accurate, if his mechanism is real, and if the short record of accurate accounting is consistent decades into the future.
Those caveats should give us caution in assigning too much cred – yet – to the newest story on sea level being passed around.
Think sea level rise will be moderate and something we can all plan for? Think again.
Sea levels could rise by much more than originally anticipated, and much faster, according to new data being collected by scientists studying the melting West Antarctic ice sheet – a massive sheet the size of Mexico.
Margaret Davidson, NOAA’s senior advisor for coastal inundation and resilience science and services, and Michael Angelina, executive director of the Academy of Risk Management and Insurance, offered their take on climate change data in a conference session titled “Environmental Intelligence: Quantifying the Risks of Climate Change.”
Davidson said recent data that has been collected but has yet to be made official indicates sea levels could rise by roughly 3 meters or 9 feet by 2050-2060, far higher and quicker than current projections. Until now most projections have warned of seal level rise of up to 4 feet by 2100.
These new findings will likely be released in the latest sets of reports on climate change due out in the next few years.
“The latest field data out of West Antarctic is kind of an OMG thing,” she said.
So there’s quite a bit of discussion among knowledgeable folks that this is overdoing it a bit, and the article cites no new research numbers to support the direst estimates.
Readers and viewers know that I’ve produced a number of videos on the issue and interviewed some of the best experts in the field – but I caution those tweeting this new meme around that, so far as I know, “the latest field data” cited here do not give us anything like 3 meters by 2050, and even Hansen’s worst case quoted above gives something like a meter by mid century, scary enough – with multi-meter rise more toward 2100.
So, plenty of reason for concern, but recall the kerfuffle with a stray sentence in the 2007 IPCC report, claiming that “Glaciers in the Himalaya are receding faster than in any other part of the world and, if the present rate continues, the likelihood of them disappearing by the year 2035 and perhaps sooner is very high.”
This statement turns out to have escaped the rigid review process, and became a talking point for climate deniers seeking to undermine the reports solidly based major conclusions.
So, bottom line, always look for specific published, peer reviewed sources for claims as important and sweeping as these. Sea level rise is already an emergency, but dealing with it means scientists and citizens have to maintain high standards for the information they rely on and disseminate.
UPDATE: Clarification from NOAA official quoted in article, to Eric Holthaus of Slate.
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