According to a new study published in Science (behind a subscription wall here), global sea levels have been falling--and will continue to fall--over time. The reason has nothing to do with global warming; instead, it's due to subsiding of the ocean floor:

"The ocean floor has got on average older and gone down and so the sea level has also fallen," said Bernhard Steinberger at the Geological Survey of Norway, one of five authors of a report in the journal Science.

"The trend will continue," he told Reuters.

A computer model based on improved understanding of shifts of continent-sized tectonic plates in the earth's crust projects more deepening of the ocean floor and a further sea level decline of 120 meters in 80 million years' time.

The reasearchers' maps show that about 80 million years ago, there would have been large inland seas in much of what is now Eastern Europe, central Asia, Australia, and South America. In another 80 million years from now (pictured), Russia will again be connected to North America via an Alaskan land bridge, Indonesia will be part of the Asian continent, the British Isles will be part of continental Europe, and all the world's major coastal cities will have moved inland.

The study points up the complexity of global climate and geographic patterns, and how narrow is our perception of what the world "should" look like. The oceans, the icecaps, and the coastlines have been in flux for millions of years, and will continue until our solar system dies. To decide that the climate, temperature, and weather patterns that we have today are the ones that should be maintained is not only chauvinistic, it is also beyond our ability to guarantee.

When elected officials insist upon a radical change in our lifestyle to achieve a desired environmental effect, they must be confident that the recommended course of action is necessary. But they must also be certain that it will achieve the desired effect on the globe. And given the seemingly daily emergence of new and heretofore poorly understood environmental phenomena, isn't it better to postpone radical policy shifts until we understand our globe better?