Discussions of "tipping points" have, in recent times, largely been relegated to the war in Iraq where such moments, regularly predicted by the Bush administration, never arrive. In the meantime, an actual tipping point may have been creeping up on us on another front entirely, one that is anathema to this administration -- that of climate change.
The latest news from scientists laboring in cold climes has been startling. The expanse of Arctic sea ice has been shrinking in the summer since the late 1970s, though usually rebounding to near normal levels in the winter. Until recently. For the last few years, winter ice cover has been shrinking as well. This will be the fourth consecutive year of record, or near record, shrinkage of September sea ice in the Arctic. Scientists speculate that a threshold has been crossed.