Island people swallowed by the sea
The BBC's David Willis travelled to the remote Alaskan island of Shishmaref, a community that is being destroyed by climate change.
It is not quite the end of the world but you could probably see it from here.
Shishmaref loomed as a dot on the landscape as our twin-engined Cessna cargo plane cut through snow-capped mountains.
We had flown to the edge of the Arctic circle, to a wilderness captivatingly beautiful yet inhospitably remote - a land where it seemed human beings were never meant to live.
At the cliff's edge
I was last here nearly three years ago to witness the effects of global warming on this community of nearly 600 people.
Right now we're living on borrowed time
For several decades the people of this barrier island have been fighting a losing battle with nature.
Not only are the glaciers melting, causing sea levels to rise, but the frozen ground on which the village was built - also known as permafrost - is thawing, making the ground crumble like sand.
Shishmaref is a community that is literally being swallowed by the sea.
Village elder Tony Weyiouanna estimates the tide moves an average of 10 feet (three metres) closer to the land every year.
Two homes have already toppled into the sea, others have wilted and buckled and now teeter ominously at the cliff's edge.
Tony told me that since I was last here the village had decided - very reluctantly - to relocate.
What they had yet to agree on was where to.
This close-knit Inupiaq community has been here for generations. Where they live defines who they are - the fear is that relocation could leave their subsistence lifestyle under threat.
A greater concern, Tony told me, was that a heavy storm could sweep the entire community into the sea.
"We need to preserve our village before that happens," he told me, "right now we're living on borrowed time."
Grocer Percy Nayokpuk says anyone who doubts the existence of global warming should pay Shishmaref a visit.
Grocer Percy Nayokpuk says there are signs the ice is cracking
Amid the frozen sea he has recently observed clouds of steam - a sign that the ice, once thick and stable, is cracking.
The fact that the village could disappear virtually at any moment has everyone worried - there have even been some suicides.
As we spoke the mercury was nudging -30C, bone chilling for a man of my warm-blooded Western sensibilities, positively tropical for the people here.
On the short plane ride from the nearby town of Nome (whose local newspaper bears the slogan: "There's no place like Nome") we met Malcolm Henry.
He wore a baseball cap, loose-fitting jacket and Hawaiian shorts.
Protruding from the shorts were legs impressively devoid of goose-pimples.
"You must be freezing?" I suggested from beneath a balaclava and six layers of clothing.
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"Man, this is warm for the time of year. I remember when it was -40C with a wind-chill factor of -60."
Everywhere we went the anecdotal evidence suggested that Alaska's winters are not only getting warmer but shorter, and its summers longer.
And the impact extends to wildlife as well: shortly after we arrived local television was carrying reports about efforts to have polar bears listed as an endangered species.
The ice caps on which they live are melting - no prizes for guessing why - causing them to come further inland to look for food and thus making them easier prey for local hunters.
Later this month a delegation from Shishmaref and other communities threatened by global warming (estimates suggest that more than 180 Alaskan villages are feeling the impact of flooding and erosion) will travel to Washington DC to provide evidence that climate change is destroying their way of life.
They will also argue that US energy policies - and the Bush administration's position on greenhouse gases - are to blame for the problem, and constitute an infringement of their basic human rights.
Whatever effect their efforts may have some believe it is already too late.
The impact of global warming is vivid. Just ask the people of Shishmaref.