David Barber, who helped lead a international expedition in the arctic, says rapid sea ice melt is affecting everything from polar bears to microorganisms.
He says there is more open ice now in the Arctic. That creates more cyclones, which in turn further erodes the sea ice crucial to the region's ecosystem. Scientists on the mission say what is happening in the Arctic is a bellwether of what will eventually happen further south.
Some 300 scientists from 27 countries spent months on an icebreaker studying climate change in the Arctic.
Meanwhile, U.S.-based Pew Environmental Group said it has quantified for the first time the economic costs of the Arctic's warming and it adds up to at least $2.4 trillion over the next 40 years.
Economist Eban Goldstein of Bard College in New York says the Arctic is warming at twice the rate of the rest of the world.
And he says the combination of melting ice, increased sunlight absorption by darker barren ground and the release of methane as the permafrost thaws will this year warm the earth the equivalent of 40 per cent of total U.S. industrial emissions.