how 'bout that heat?

Scientists are worried about global warming. This is nothing new, but a report has just been released on the state of ice in the Arctic that is rather alarming. For quite some time, we've been seeing ice in the arctic melting - each year, there's less than the year before. In the past 4 years, however, that rate has been accelerating. Sharply. So each year, there's not only less ice than the year before, we've also lost more than we did last year. The reason is a positive reinforcement effect. Ice reflects sunlight a lot more than water does, so as the Arctic becomes less icy and more watery, it also absorbs even more heat.

So what, you say? Well, while most of the ice in the arctic is floating, there's also a lot of ice on Greenland. When landlocked ice melts, it flows into the oceans, and sea levels rise considerably. Most Antarctic ice is landlocked, and the south pole is showing similar behaviour. Ice is also a great heat sink: as your grade 10 science teacher no doubt demonstrated to you, a class of ice water stays at about 0 degrees C until all the ice is melted. But once the ice is gone, the temperature starts to rise. And temperature is the driving force for weather like, oh, say, hurricanes.

If you think Katrina was bad, wait 30 years. If things keep going at current rates, we could see a storm with winds many times as strong flooding the coastal city of Dallas.