New research has brought forward the earliest date by which the Arctic ice cap might completely disappear in summer to 2040
That's pretty soon. Looking back at the many stories we've written over the last few years, the date was 2100 back in 2002
, but had moved up to 2070 by 2004
I suspect that's because the new work included feedback mechanisms which accelerate the warming – the researchers talk about fast approaching a "tipping point". The feedbacks include the fact that less ice means more of the Sun's warmth is absorbed by the darker ocean, rather than being reflected. The team also say the melting ice will change ocean currents, meaning more warm water is brought northwards.
Things have certainly been hotting up in the Arctic for some time. The loss of summer ice between 2004 and 2005 was 17%
– about the size of Texas. The area covered in 2006 was slightly bigger than 2005, but still the 4th lowest in the last 29 years.
The extent of winter ice has also been decreasing
and scientists say the Arctic is warming at twice the rate of the rest of our planet
There might be one bonus (if you are not a polar bear
) – the opening of new shipping routes through the Arctic. This could shorten journeys by many thousands of miles, saving fuel and greenhouse gas emissions.
But even this benefit is double-edged. Researchers says new northern passages could significantly boost levels of low-lying ozone
as ship exhausts pump pollutants into the pristine environment, which could affect wildlife.
And there's even some suggestion that a melting Arctic ice cap could have the knock-on effect of drying out the west coast of the US
The prospect of a completely ice-free Arctic within our lifetimes is pretty damn dramatic. Could this be the factor which tips politicians from talking about the greenhouse gas cuts the scientists say are needed, into actually making them happen? Let me know what you think.Damian Carrington, Online Editor