climatereason | July 29, 2015 at 4:03 am |
Vaughan
I suspect that JIm D got that figure from here.
http://ngm.nationalgeographic.com/2013/09/rising-seas/if-ice-melted-map
tonyb
As a courtesy to VP I tried to find where this claim comes from.
I took the logical step of “asking a scientist” to see what a scientist thinks to establish the facts.
http://www.amnh.org/ology/features/askascientist/question18.php
If all the ice covering Antarctica, Greenland, and in mountain glaciers around the world were to melt, sea level would rise about 70 meters (230 feet). The ocean would cover all the coastal cities. And land area would shrink significantly. But many cities, such as Denver, would survive.
The increase in surface area is why the increase in sea level is only 70 m. Which means most ice melt sea level claims are 50% too high.
Now to where the claim came from:
http://water.usgs.gov/edu/watercycleice.html
Which points to:
http://nsidc.org/glaciers/quickfacts.html
Which is a dead link.
The active link is the glacier quick facts page::
https://nsidc.org/cryosphere/glaciers/quickfacts.html
“If all land ice melted, sea level would rise approximately 70 meters (230 feet) worldwide.”
Presumably either the original NSIDC page was wrong, or more likely – someone in the USGS was cruising the NSIDC glacier quickfacts page and thought the 70 m just applied to glaciers. The USGS seems to defer completely to the NSIDC on matters of ice.
The NSIDC site has some other troubling statements: “Glacierized areas cover over 15 million square kilometers (5.8 million square miles).”.
They define half of the world’s ice sheets as glaciers.
http://www.livescience.com/24168-glacier-volume-sea-level-rise.html
“Researchers calculated the ice thickness for 171,000 glaciers worldwide, excluding the Greenland and Antarctic ice sheets, which hold the bulk of Earth’s frozen water. Through a combination of direct satellite observations and modeling, they determined the total volume of ice tied up in the glaciers is nearly 41,000 cubic miles (170,000 cubic kilometers), plus or minus 5,000 cubic miles (21,000 cubic km).
If all the glaciers were to melt, global sea levels would rise almost 17 inches (43 centimeters), the scientists found.”
And that’s the way it is.
100,000 km3 is as a good a number as any for glacier volume.