Thursday, April 19, 2007

Global Warming to Shorten Our Days

Global warming is literally going to shorten our days, according to a recent study:

As water warms, it expands, causing sea level rise. Felix Landerer of the Max Planck Institute for Meteorology in Hamburg, Germany, and his colleagues used a computer model to find out what effect this expansion will have on the distribution of water around the globe....

Two factors mean that this tends to move water's mass away from the equator and towards the poles. First, the depths of the North Atlantic should warm more quickly than depths elsewhere, thanks to a current there that carries water down from the surface. So the expansion and movement of water is strongest there. Second, a quirk of our planet's geography means that the continental shelf's surface area happens to be larger at high latitudes than around the equator.

Having more mass at the poles, which is closer to Earth's axis of rotation, will make the planet spin faster.

But not to worry: the shortening will be by only 0.12 milliseconds over the next 200 years, according to Landerer.

No comments: