Letter to the editor: Sea levels are indeed rising

Posted 5/18/23

To the editor,

A recent letter to the editor by Ken Pazdernik asks for an intrepid science teacher to explain melting polar ice. I taught geology courses, including oceanography, at …

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Letter to the editor: Sea levels are indeed rising

Posted

To the editor,

A recent letter to the editor by Ken Pazdernik asks for an intrepid science teacher to explain melting polar ice. I taught geology courses, including oceanography, at U.W.R.F. for 40 years, so maybe I qualify.

The Archimedes principle does indeed apply to floating ice, such as on the Arctic Ocean. However, most of the world's glacial ice rests on land - Antarctica and Greenland - and the melting of this ice is going on at an unprecedented rate. The water from ice melt on land has raised and will continue to raise sea level. Picture a glass filled to the brim with ice and water, positioned under a steadily dripping faucet. The glass will slowly overflow. Perhaps Mr. Pazdernik does not see the effects of sea level rise because he lives in Wisconsin - far from any seacoast. Sea level rise is a measurable reality. The effects show best in this country in places like Florida, Louisiana and the north coast of Alaska where the seaward slope of the land is low. Here coastal land loss is well documented, as are the increasingly devastating effects of king tides and storm surges. These reach inland much further than they used to due to a higher sea level. Much federal and local money is being used to armor our seacoasts and fix the damage done by these hazards.

The melting of Arctic sea ice illustrates a different aspect of global warming. Ice and snow reflect sunlight back into space quite well, as us Wisconsinites know. This has a cooling effect. Replacing Arctic sea ice with open water (lower Albedo) causes less sunlight to be reflected, and thus more heat to be trapped by warming Arctic waters. This warms the overlying air, and increases evaporation. Warmer air holds more water, increasing rain and snowfall on land. We shoveled some of this off our driveways last winter. For anyone interested, there are a number of books on climate change. A good one for the general reader is Steven's Earle's Brief History of the Earth's Climate, available on Amazon and elsewhere.

William S. Cordua, PhD.

Emeritus professor of geology, UW - River Falls

climate change, sea levels, Arctic ice caps, letters, opinion