Over the last few winters, there’s been less ice on the Great Lakes. The experts say records don’t go back far enough to know how unusualthat is. However, some scientists note that less ice cover on the lakescould be the region’s first notable effect of global warming. The GreatLakes Radio Consortium’s Lester Graham reports on what less ice couldmean in the future:
Transcript
Over the last few winters… there’s been less ice on the Great Lakes. The
experts say records don’t go back far enough to know how unusual that is.
However, some scientists note that less ice cover on the lakes could be
the region’s first notable effect of global warming. The Great Lakes Radio
Consortium’s Lester Graham reports on what less ice could mean in the
future.
The National Oceanic and Atmospheric Administration’s Great Lakes
Environmental Research Lab is putting together a puzzle. It’s piecing
together the history of ice on the Great Lakes. When it’s finished it will
have 30 years of specific data and a rough sketch over 150 years. Shipping
companies will find an immediate use for the records to better plan the
shipping seasons.
But scientists are interested in something else. Although the ice records
are incomplete right now, the Great Lakes Environmental Research Lab
has noticed one thing… the last few years have seen a lot less ice. Raymond
Assel is one of the researchers involved in the project.
“If we continue to have these relatively mild ice seasons, say for the next five years or so, then that would certainly indicate that we are under a new ice cover regime in the Great Lakes region. But, it’s much the problem that we have with trying to detect global warming. I mean, you know, once you can tell positively that you have it, you’ve already been in it for a while.”
Assel is not saying global warming is causing less ice on the Great Lakes.
But… he says it fits the scenario some scientists have predicted.
In fact… an economist at the University of Chicago has studied how the
Great Lakes region might be affected by global warming. Richard Kosobud says
one obvious expectation is that there’d be less ice. That would be good news
and bad news. There would likely be a longer shipping season because the ice
wouldn’t block the channels and the harbors. But Kosobud says because
ice covers open water, it prevents evaporation… less ice means greater
evaporation. And the same weather that reduced the ice might mean less
snow melt and ultimately lower lake levels… just like we’ve seen the past few
years.
“Now if that happens, then shipping is going to be adversely affected because some of these big boats barely squeeze in now. They’ve been designed to maximize profits. And if you have a declining Great Lakes level, even say a foot or a little less on the average over the next 35, 40, 50 years, there’s some cost to be incurred there.”
Most mainstream atmospheric scientists now agree that global warming is
real. And Kosobud says researchers in other disciplines are also trying to
assess the changes that might be coming. As an economist Kosobud
calculates the economic impacts could be great. Something planners and builders
around the great lakes should keep in the back of their minds.
“I don’t think we should spend huge amounts of money now trying to protect ourselves from this, but we certainly should be looking at them. And if we make long-run investments, like building a boat dock or looking at surfacing the shores of the Great Lakes, we should have these long-run impacts in mind.”
Kosobud is most concerned about the effects on the lakes ecosystems. He
says less ice and lower levels might change fish species in the lakes… affecting
ice fishing and the rest of the multi-million dollar sport fishing industry.
At the Great Lakes Environmental Research Lab the scientists have also
been wondering about the possible effects on fish and wildlife if the trend of
less ice cover continues. Raymond Assel says there are too many variables
and too little data to make any solid predictions.
“It’s certainly going to have some impact, but it’s very difficult to say exactly how it’s going to play out in the entire ecosystem of the
Great Lakes.”
Not all scientists are quite as cautious in their approach as those at the
Great Lakes Environmental Research Lab. Other scientists say there are
some assumptions you can make. Dan Lashof is a senior scientist with the
environmental group, Natural Resources Defense Council. He says it’s a
pretty safe bet the reduction in ice on the Great Lakes is part of a global
warming trend.
“So along with reduced ice cover, the Great Lakes region can expect a range of other impacts including reduces in lake levels, which we’re also seeing in recent years, possibly decreases in the oxygen concentration in lake water that would reduce the productivity of the Great Lakes, and loss of habitat for a range of species that currently inhabit the region.”
Lashof says with most scientists agreeing on global warming, it’s not too
early to start planning now.
“Well, I think it is sensible to anticipate that the climate will continue to change. Of course at the same time we should be doing everything we can to reduce the pollution that causes global warming.”
In the meantime, the scientists at the Great Lakes Environmental Research
Lab are compiling Great Lakes ice maps from several sources and comparing them from year to year. They hope to soon be able to tell whether the
current pattern is just a temporary weather pattern change… or part of
an ongoing warm-up of the planet’s surface.
For the Great Lakes Radio Consortium, this is Lester Graham.