Global warming? Bet on it.

While global warming may have only become a popular issue in 2006 with the release of An Inconvenient Truth with Al Gore, the citizens of a tiny town in Alaska have been watching (and betting) on global warming for a lot longer than that.

Since 1917, the town of Nenana, Alaska (population 402), which is about 55 miles southwest of Fairbanks, has sponsored the Nenana Ice Classic. This is a lottery where participants wager on the exact moment when the ice breaks up on the Tenana River. Every year, you can buy a ticket for $2.50 and put your money on the exact date and time when the ice will break up, which indicates the unofficial start of spring. Last year, 22 people won and shared a jackpot of over $300,000.

The break-up of the ice is measured using the Nenana Tripod, which is a 26-foot tall pyramid of spruce logs that are anchored into the ice. When the ice breaks up, the tripod (which actually has four legs) will collapse and trigger a trip wire which will stop the clock.

By happenstance, the Nenana Ice Classic offers a rare opportunity for scientists to measure the acceleration of global warming over the 20th century by measuring how the winning times have shifted over the past 90 years. In fact, the winning time has occured almost 10 days earlier since 1960.

No instruments, no fancy equipment, no big movie deals, just a small town that has seen their backyard change a little bit every year.