The melting of ice in the Arctic could result in economic costs of between $2.4 trillion (£1.54tn) and $24 trillion by 2050, according to a major new study that predicts that the loss of "the planet's air conditioner" will accelerate the rate of global warming and lead to an increase in losses associated with heat waves, rising sea levels and other climate change effects.

The study, which was commissioned by the Pew Environment Group, was presented to G7 finance ministers gathering for a two-day meeting on Canada's Baffin Island.