Environment & Energy
Related: About this forumAvg. Global Annual Net Ice Loss - 385 Billion Tons - Filling Lake Erie Eight Times Over
There isnt a doubt in the world (among serious scientists, anyway) that the sea has been rising for the past century, by about eight inches in total since 1900. Theres little doubt, either, that the rise has been speeding up over the past couple of decades the water has been inching up about as twice as fast lately as it was for most of the 20th century.
All of that is a powerful confirmation of what thermometers tell us: that the Earth is warming the result, say those same serious scientists, of human-generated, heat-trapping greenhouse gases. That heat makes seawater expand, and it also transforms land-based ice into even more water that swells the oceans further.
What nobody has firmly pinned down so far, though, is just how big a contribution all that new water makes to the rising seas. Theyve come up with an estimate, by calculating how much should come from heat expansion then blaming the rest on melting ice: about 1.8 millimeters per year, says University of Colorado physicist John Wahr. But thats not as convincing as a direct measurement, and it doesnt solve the mystery of where all the ice is disappearing from.
Now, however, thanks to Wahr and three other scientists, the measurement question and the mystery have both been answered. Using a high-flying pair of satellites known collectively as GRACE, the Gravity Recovery and Climate Experiment mission, theyve been watching carefully since 2002 to see, among other things, which of the planets glaciers and ice sheets are shrinking and by how much. The answer, just reported in Nature: between 2003 and 2010, about 385 billion tons of ice have vanished into the sea each year enough, says Wahr, to fill Lake Erie with water eight times over, or cover the entire U.S. with water to a depth of a foot and a half.
EDIT
http://www.climatecentral.org/news/how-much-ice-is-vanishing-into-the-seas-you-dont-want-to-know/
happyslug
(14,779 posts)For more on Lake Erie see:
http://en.wikipedia.org/wiki/Lake_Erie
Unlike Superior the average time it takes for Erie to empty and refile is 2.7 years (Every 2.7 years the water in Lake Erie has flown out of Lake Erie to be replaced by other water from Lake Huron).
Lake Superior takes 191 years to do the same, i.e. 191 years for the same amount of water in Lake Superior to flow out of the lake to be replaced by new water that flows into the lake.
For more on Lake Superior:
http://en.wikipedia.org/wiki/Lake_Superior
I do NOT want to minimize how much ice is disappearing, just trying to make sure everyone knows how much water is being lost.
Lake Ontario, the Second smallest lake, takes six years to empty and refill.
http://en.wikipedia.org/wiki/Lake_Ontario
lake Huron 22 years
http://en.wikipedia.org/wiki/Lake_Huron
Lake Michigan 99 years:
http://en.wikipedia.org/wiki/Lake_Michigan
Thus, while it would take 8 Lake Eries, that is about 3 and a 1/2 Lake Ontarios, 1/2 of Lake Huron, about 1/5 Lake Michigan, and about 1/10 Lake Superior.
To compare any lost of Ice to any of the Great Lakes shows how great a loss it is, but lets also keep the loss in its proper perspective.
joshcryer
(62,276 posts)It's all downhill from here.