12 Jul 1997 Global Warming, If It Occurs, Could Lower Sea Level
The Science & Environmental Policy Project
4084 University Drive, Suite 101
Fairfax VA 22030
For Immediate Release
Contact: Candace C. Crandall
e-mail: [email protected]
GLOBAL WARMING, IF IT OCCURS, COULD LOWER SEA LEVEL
Ice Accumulation at the Poles Will Likely Offset Any Glacial Melting
FAIRFAX, VA, JUNE 24, 1997—Fears of a catastrophic rise in sea level due to a possible future global warming may prove groundless, according to Dr. S. Fred Singer of the Science & Environmental Policy Project in Fairfax, Virginia. In a research paper just submitted for publication, Singer reports an anti-correlation between sea surface temperature and sea level rise, the reverse of what was expected by the UN’s scientific advisory group, the Intergovernmental Panel on Climate Change (IPCC).
Sea level has been rising steadily for more than a century, and perhaps for several centuries before that. Most researchers attribute this rise to gradual changes in the ocean basins–in other words, plate tectonics. The IPCC has predicted with some certainty that a warming of the earth’s climate–resulting in glacial melting and thermal expansion of ocean water–would accelerate this rise.
Singer says there’s an offsetting factor. “As temperatures warm,” he says, “the rate of surface evaporation accelerates, which leads to more precipitation. This would come down over the polar regions as snow, thickening the ice caps of Greenland and the Antarctic and transferring water from the oceans to the ice sheets.
Scientists have know for some time that in the event of a global warming, both mechanisms–glacial melting/thermal expansion and increased precipitation/thickening ice caps–would be in play. It wasn’t known, however, which mechanism would be the most important.
Last fall, while doing research for his forthcoming book, Global Warming: Unfinished Business, Dr. Singer observed in a paper published by A. Trupin and J. Wahr in the Geophysical Journal International that this steady rise in sea level slowed significantly during the period from 1920 to 1940, a time of rapid warming as the earth recovered from the “Little Ice Age.” Singer decided to do a statistical analysis of all the available data on sea level, and to compare it with sea surface temperature and global temperature. What he discovered was a strong anti-correlation that held over the entire record, since the beginning of this century.
“Sea level has been going up about 1.8 millimeters per year for reasons other than climate change, and it will likely continue to go up,” says Singer. “But what the data seem to show is that when temperatures get warmer the rate of rise slows considerably.” If this is confirmed by direct measurement of ice accumulation in the Antarctic, it would indicate that with any future warming a transfer of water to the polar regions, in the form of ice, would more than offset any glacial melting and thermal expansion. “And that would be good news,” says Singer, “to those concerned about coastal flooding.”
For additional information on global warming research, visit the SEPP web site at http://www.his.com/~sepp/.