A United Nations panel says temperatures in the Canadian Arctic have been rising at almost double the global rate, mainly because of greenhouse-gas emissions.
Coming on the eve of a G8 meeting looking for ways to reduce heat-trapping emissions from industry and automobiles, the UN's "Global Outlook for Ice and Snow" says Canada's Arctic, along with north-central Siberia and the Antarctic Peninsula, has registered the largest temperature increases of any place on Earth.
"Ice and snow are important components of the Earth's climate system and are particularly sensitive to global warming," says the report, citing "substantial," documented decreases in ice and snow over the last few decades.
"Changes in volumes and extents of ice and snow have both global and local impacts on climate, ecosystems and human well-being."
Arctic temperatures will continue to rise through the 21st century, melting glaciers that will raise sea levels by up to a metre, affecting millions of people worldwide, says the report by more than 70 experts. And with critics calling PM Stephen Harper's emissions-reduction plan at best ineffectual and at worst counter-productive, the UN report urges decisive measures to tackle the problem before it snowballs.
"To avoid further and accelerated global warming with major negative consequences, greenhouse gases must stop increasing and start decreasing no later than 15 to 25 years from now," says the document released earlier in the week.
"Economic assessments indicate this is achievable without significant welfare losses."
Harper has dismissed fixed caps on Canada's greenhouse-gas emissions, saying they will devastate the economy. He's in Europe this week touting a plan to link emissions to industrial production by establishing so-called "intensity targets."
Critics such as Green Party Leader Elizabeth May have called the plan a recipe for disaster.
The UN says Arctic sea ice has disappeared at a rate of 8.9 per cent a decade over the last 30 years, and it predicts a "mainly ice-free Arctic Ocean in summer by 2100 or earlier."
The declines in ice and snow will only compound the warming effects of greenhouse-gas emissions because snowless land masses and iceless oceans will absorb rather than reflect more of the sun's warmth, says the report.
While there has not yet been widespread thawing of permafrost, the report warns that climate change is expected to cause a thaw across the subarctic by century's end.
Such a melt would further compound global warming because permafrost, especially its upper layers, stores "a lot of carbon," the report says.
"Permafrost thawing results in the release of this carbon in the form of greenhouse gases which will have a (detrimental) effect to global warming."
The report warns some sea-ice dependent organisms from bacteria to polar bears are already at risk because of melting ice and declining habitat.
Ironically, it notes that the increasing extent of open water in the polar regions will allow easier access to exploration for oil and gas, energy sources responsible for much of the planet's greenhouse-gas emissions.