By Donella Meadows
–February 1, 2001–
The place to watch for global warming — the canary in the coal mine — is the poles. If the planet as a whole warms by one degree, the poles will warm by three degrees or so. Which is precisely what is now happening.
The Arctic Ocean has 15 percent less ice cover than it did 20 years ago. In the 1950s that ice averaged 10 feet thick; now it’s less than six feet thick. At the current rate of melting, in 50 years the Arctic could be ice-free all summer long.
That, says an article in the January 19 Science, would be the end of the polar bears. In fact most creatures of the Arctic Ocean are already in trouble.
I bet you didn’t know there were many creatures of the Arctic Ocean. Neither did scientists, until they started looking. In the 1970s a Russian biologist named Melnikov discovered 200 species of tiny organisms, algae and zooplankton, hanging around ice floes in immense numbers, forming slime jungles on the bottoms of bergs and plankton clouds in every break of open water. Their carcasses fall to the bottom to nourish clams, which are eaten by walruses. Arctic cod scrape algae off the ice. The cod are eaten by seabirds, whales, and seals. King of the food chain is the great white bear, which lives mainly on seals.
That was the system, until the ice started to thin. Melnikov returned to the Beaufort Sea in 1997 and 1998 and found most of those tiny critters, many of them named by him (and for him), gone. The ice was nearly gone. Creatures dependent on the plankton (like the cod), or on the ice for dens (seals) or for travel (bears) were gone too.
Many had just moved north, following the ice, but that means moving farther from land, with widening stretches of open water between. Creatures like the sea bird called the black guillemot that depend on land for shelter and the ice floe community for food can no longer bridge the gap.
The Arctic is changing faster than scientists can follow. Inuit hunters report that ivory gulls are disappearing; no one knows why. Mosquitoes are moving north, attacking thick-billed murres, which will not leave their nests. The birds die on their eggs, sucked dry by the bugs. Caribou can no longer count on thick ice to support their migration from island to island. One wildlife biologist who spots caribou from the air says, “You sometimes see a caribou trail heading across [the ice], then a little wormhole at the end with a bunch of antlers sticking out.”
Hudson’s Bay polar bears are thinner and are producing fewer cubs. With the ice going out earlier, their seal-hunting season is shrinking. Hungry bears retreat to land and ransack garbage dumps. The town of Churchill, Canada, has more jail cells for bears than for people. The bears are also weakened by toxic chemicals that drift north from industrial society and accumulate in the Arctic food chain.
The most recent five-year study from the world’s climatologists, just released, erases any doubt about where this warming is coming from and warns that we ain’t seen nothing yet. If we keep spewing out greenhouse gases according to pattern, the warming over the 21st century will be three to ten times more than we have seen over the 20th.
Some biologists are saying that the polar bear is already a doomed species.
It doesn’t seem fair, does it, that the Arctic, the one place we’ve hardly trampled, the last pristine wilderness dream, should suffer first and most from our inability to control ourselves and our so often ignoble passions.
Copyright Sustainability Institute 2001