UpDate - Vol. 11, No. 22, Page 9
March 5, 1992
Change in weather may affect Delaware sea level

     In the last 2 million years, the Earth has never been more
than 4-5 degrees Fahrenheit warmer than it is today. Since the
Wisconsin glaciation peaked 18,000 years ago, the Earth has warmed
about 7 degrees and, in the last century, about 0.7 degrees.
Warming in the next century could be 10 times as rapid as the
historical warming trend.
                         - University Sea Grant Report

     Under a worst-case scenario, sea level rise induced by global
warming could push Delaware's coastline 6 miles inland in just one
century, according to a report issued in December by the University
Sea Grant Program.
     However, the sharp rise in global temperature needed to cause
such a  radical move by the sea is unlikely to occur, says Pat Marx
Washburn, the report's author. She says the possibility the sea
level will rise by 20 feet-the amount that would accompany a 6-mile
surge by the sea-is just one of a myriad of research-based
predictions about global warming and its impact on the sea.
     In a less dramatic scenario, Washburn, a 1981 graduate of the
University's master's program in geology, reports that the same
researchers have predicted similar results over a 1,500-year
period, given that the sea level "continues to rise at rates we
have had over the past 50 years."
     During the last century, sea levels rose by 4 to 6 inches,
according to a 1983 study.
     Washburn's report, Sea-Level Rise: How Could a Potential Rise
in Sea Level Due to Global Warming Affect Delaware?, considers
several research studies, including some undertaken at the
University of Delaware and by the Environmental Protection Agency
(EPA).
     There are many plausible scenarios relating sea level rise to
global warming, Washburn says. No one can be sure which predictions
are most likely to occur, however, because of natural "feedback
mechanisms" that could serve to increase or decrease the rate of
sea level rise. It is "very possible," she says, that some natural
phenomenon will promote sea level rise while another simultaneously
combats it.
     Two examples of poorly understood feedback mechanisms are
clouds and oceans, Washburn says.
     According to the report, "The lack of information about how
clouds will be affected by global warming and the amount of heat
the oceans can absorb and distribute leads to a tremendous degree
of uncertainty."
     Assuming some sea level rise over time, Washburn says there
are going to be three unavoidable effects on Delaware: a westward
movement of the shoreline, flooding of the coast and saltwater
intrusion into the wetlands. In her report, she suggests government
action now to allow for the movement of homes and businesses later.
     The purpose of the report, Washburn says, is to make "those
responsible for managing our natural resources" aware of the range
of possibilities associated with global warming and sea level rise.
     For a copy of the report, contact the office of Marine
Communications at 831-8083.
                                        - Stephen M. Steenkamer