The North Pole could be free of ice during the summer by 2040 thanks to the dramatic effects of global warming, a new scientific study has warned.
The ice-bound ocean could melt, bringing disaster for many arctic animals including polar bears, the American Geophysical Union Autumn Meeting was told.
Scientists reported that the Arctic sea ice, which has shrunk over the past 30 years, is not recovering fully in the winter months. In November, ice coverage was about 800,000 square miles below average, the least amount of sea ice ever recorded by satellites.
"That's an area the size of Alaska," said leading ice expert Mark Serreze of the University of Colorado. "We're no longer recovering well in autumn anymore. The ice pack may now be starting to get preconditioned, perhaps to show very rapid losses in the near future."
A computer prediction showed that by 2040, only a small amount of permanent sea ice will remain along the north coasts of Greenland and Canada, while most of the Arctic basin will be ice-free in September.
Scientists also reported that carbon dioxide emissions linked to global warming are cooling and shrinking the outermost atmosphere where the international space station and other satellites orbit.
The thinning of the thermosphere, which begins about 60 miles above Earth and extends up to 400 miles, reduces the drag on orbiting spacecraft, keeping them airborne longer. The downside is that the lifetime of space junk is also extended, which can pose a threat to satellites.
Researchers have long predicted that carbon dioxide, a greenhouse gas produced when fossil fuels such as oil and natural gas are burned, would cool the outer atmosphere.
