Gambling contest pays off for climate researchers | WWF

Gambling contest pays off for climate researchers

Posted on 06 November 2001    
A gambling contest in Alaska’s interior is providing researchers with a remarkably accurate record of global climate change, according to a new study in the journal Science. The results show that spring is coming earlier and earlier.
Every year, the 500 residents of Nenana host the Nenana Ice Classic, a popular event that awards cash prizes to those lucky enough to guess when the annual ice breakup will occur on the nearby Tanana River, about 80 km southwest of Fairbanks. Winners must predict the exact minute that a specially constructed wooden tripod will crash through the icy surface.
Hundreds of thousands of people pay $2 a ticket to enter the contest. This year’s jackpot of $308,000 was divided among 18 winners who accurately predicted that the tripod would fall through the ice on Tuesday, May 8, at exactly 1 p.m.
Writing in the October 26 issue of Science, Stanford University researchers Raphael Sagarin and Fiorenza Micheli analyzed the entire Ice Classic record and discovered that, on average, the Tanana River breakup occurs 5.5 days sooner than it did back in 1917 when the contest began.
"These results show that springtime is coming earlier," notes Sagarin. "This trend also matches up pretty well with historic temperature data from Nenana and Fairbanks."
The Nenana Ice Classic was created by engineers building a railroad bridge across the Tanana River. When the river froze, the engineers had to stop work. According to Ice Classic historians, idle speculation about when the ice would break up is what led to the wagering.
To determine the contest winner, the engineers came up with an ingenious contraption still in use today. It consists of a tall tripod made of wooden logs painted with black-and-white stripes. A wire is attached from the top of the tripod to a clock on shore. When melting ice causes the tripod to move 100 feet, the clock stops automatically.
"Contest records of the exact minute of ice breakup date back to 1917 and can be considered quite accurate, as the high stakes lead to constant vigilance at the time of breakup," write Sagarin and Micheli.
"The Nenana contest may be especially valuable because it is based on a more consistent definition of ice breakup than many records," they add. The authors point out the river ice breakup is caused by a combination of thermal effects–when the ice "rots" or melts slowly–and dynamic effects–mechanical forces from upstream drift ice.
"Warmer climate would be expected to advance the time of breakup through both thermal effects and dynamic effects, due to thinning ice and increased snowmelt runoff into rivers," explain Sagarin and Micheli. They go on to describe how the Ice Classic and other historical records can serve as valuable tools for researchers studying global change. "Because scientists weren’t thinking about climate change 80 or 90 years ago, it’s really important that people kept these data. This is non traditional scientific knowledge, but simple observations are very important. For example, river ice breakup has direct economic consequences, because people who live along the Tanana relay on waterborne commerce."
Other records from around the world documenting the springtime appearance of birds and new plant growth also reveal that spring is coming sooner each year, an indication that climate change is a reality that affects natural systems on Earth. WWF is currently working on the Kola Peninsula to study the annual timing of natural events such as leaf out, first frost, and bird migration, for further evidence of changes taking place in the Arctic.
For further information contact:
Lynn Rosentrater, Climate Change Officer, WWF Arctic Programme, tel: +47 22 03 65 02, mob: +47 99 15 76 64, email:

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