THAT infamous “tipping point” beyond which we foresee dangerous and unstoppable changes to global climate may be even closer to hand. Over the past two years, two of Greenland’s largest glaciers have doubled the speed at which they are falling into the sea (see “Glaciers slip-sliding away”). It’s a sure sign of global warming, especially since another giant Greenland glacier was spotted speeding up in 1998. If the Greenland ice sheet melts entirely, it would raise sea levels six metres or so over only a few centuries, flooding many densely populated areas of the planet.
Technically we have the…
