An eight-nation report by 250 scientists last month predicted the Arctic Ocean could be ice-free in summer by 2100 because of a build-up of heat-trapping gases in the atmosphere, mainly from burning fossil fuels in cars or factories.

"Santa may have to move from the North Pole within our children's lifetimes," Norris said. Young people learn that Father Christmas' workshop produces millions of gifts delivered by Santa on a flying, reindeer-drawn sleigh.

Hollywood movies like Warner Bros.' "The Polar Express" bolster belief that Father Christmas lives at the North Pole even though Nordic nations Finland, Denmark, Sweden, Norway and Iceland all argue they are his home.

Superman also has an icy retreat, the "Fortress of Solitude", near the North Pole that could be under threat in a warmer world.

A Danish official suggested rescuing Santa by building a giant floating ice rink for the workshop if the Pole thaws.

"Why don't we build some electrical facilities to ensure the ice stays on the North Pole for him?" said Alan Boldt, spokesman of the Danish Ministry of Science. "This should be a subject for the United Nations."

He said Danish group Vestas could build windmills to provide Santa with power.

Copenhagen says Santa's real home is Greenland but reckons that a Danish territorial claim to the North Pole in October clinches its case. Sovereignty over the Pole could let Denmark search for oil and gas as the ice recedes.

"Doesn't he already speak Danish?" Boldt said frostily when asked if Father Christmas would be forced to learn Danish if Denmark won international recognition of its claim to the Pole.

Last month's Arctic report said the region is warming twice as fast as the rest of the globe, partly because dark ground or water, once uncovered, soaks up more heat than ice or snow.