Unwanted whale bones are dumped at Point Barrow, the US' northernmost tip
BBC environment correspondent David Shukman travels to Alaska, to find out how the Arctic's people and ecosystems are coping with the change to a warmer climate.
Sea-ice during the 2007 melt season shrank to its smallest extent since satellite measurements began in 1979. This season's minimum, which will be set in the next few days, will come close to last year's record.
THURSDAY 11 SEPTEMBER
David Shukman takes a flight over US Arctic oilfield
I get nervous on rollercoasters, all that lurching at high altitude, so I usually avoid them. But duty calls on our patrol flight with the US Coast Guard.
Lurching at high altitude was an adrenaline rush
One of the great challenges of filming from any aircraft is that the windows are often small or grubby, or obstacles make for an awkward angle. But that isn't a problem this time: the pilot of the huge plane calmly announces he'll "open the ramp". Do what? Open the loading ramp at the back of the plane. In mid-air. With us standing on it.
Duncan Stone and I are led to the gloomy rear of the hold and are very carefully fitted with heavy straps - like tough seat-belts that are hooked to the floor.
Dark into light
Everything is double-checked. We then watch as a view of the dark interior is transformed into a stunning panorama of the Arctic landscape as the ramp descends.
The wind rushes in, the temperature falls, the noise is incredible. But there, flowing below us, laid completely bare, are mile after mile of Arctic Ocean, oil pipelines, orange flares of gas burning bright against the grey skies.
It feels a bit like surfing, standing on the icy metal floor and looking out, surging over this remote shore - yet actually feeling surprisingly safe. The odd lurch of turbulence does trigger surges of adrenaline - OK, it's pure fear - and the two loadmasters with us occasionally tighten our straps, and edge a little closer. But as a platform for filming the ice-free Arctic waters and the endless oil installations of Prudhoe Bay, it's incomparable.
Oil, an emerging issue for the Arctic, throws up contradictions. One of the Inupiat whalers we meet complains about the retreat of the sea-ice (which scientists believe is caused by man-made greenhouse gases) and also about the rising price of fuel for his hunting boat (which emits more gases as it travels further to reach the ice).
Old and new
There's also the puzzle of how modern life meets an ancient culture. I'm in the office of an Internet company which kindly lends us a fast connection to London.
This is typically hi-tech. But into this world steps an Inupiat woman with questions about broadband. I notice that she's brought her baby, not in a pushchair but in the hood of her fur-lined anorak, the classic way of these Arctic people. Barrow is like that, and I wonder how the push of oil and the retreat of ice will change it.
I also wonder what John Barrow would have made of all this? He was the Royal Navy official the town was named after, the 19th century figure who drove the exploration of the Arctic more determinedly than anyone - launching expeditions to search for the North West Passage. Mark Georgiou and I were in the team that made the journey along that route last year.
We pose for pictures at Point Barrow, a large whale bone marking the northernmost spot of the United States. There's no ice to be seen. When I started this job five years ago, the forecasts were for an ice-free Arctic in the summertime by the end of the century. The prediction now is that that could come by 2013. These past few days have made that believable.
WEDNESDAY 10 SEPTEMBER
All that's left from the last hunt are a few staggeringly large bones
Something about crossing the Arctic Circle makes us all hungry.
It happens every time but, unlike many similarly remote polar spots, Barrow is relatively blessed with places to eat.
It can lead to some surreal experiences. There's a jolly Mexican place - serving tacos in the tundra. A favourite is Arctic Pizza.
Last night in the local Chinese restaurant, producer Mark Georgiou, cameraman Duncan Stone and I were all stunned by the heat of the chicken noodle soup. I didn't know they had chilli in the Arctic.
What would those early polar explorers make of this astonishing global cuisine?
It was only in the early 19th Century that Sir John Franklin, trying to get through to Alaska via the still-elusive Northwest Passage, famously got so hungry that he ate his boots, unadorned with any kind of spice.
Some of the eating experiences in Barrow can verge on the surreal
Of course the local Inupiat people enjoy produce which is, how shall I put it, a bit more local. Like whale and seal. They aren't allowed to sell it but we hear about the elaborate rituals involved.
If the skipper of a boat lands a whale, he's entitled to the prime cut but his wife then has to prepare the meat and, when it's ready, hoist a flag and allow in anyone to help themselves.
Nothing is wasted. Unwanted blubber and bones are dumped out at Point Barrow, America's northernmost point.
In a country not renowned for its recycling, this is rather a clever environmental tactic: instead of going into landfill, the offcuts of whale act as a lure for polar bears and keep them at a safe distance from the town.
Hunting scraps: Enterprising bears know a free lunch when they see one
All that's left from the last hunt are a few staggeringly large bones. At the moment, the polar bears have to look elsewhere. We spotted one roaming among some wooden huts hunting for scraps.
It seized a large piece of seal meat from a drying rack and hurried away to enjoy it in the sea.
It lay back in the gentle waves tucking in, looking relieved to be getting a meal.
I know that look all too well.
TUESDAY 9 SEPTEMBER
2,000km from the North Pole, Barrow is the northernmost US town
First impressions can be misleading.
From the air, Barrow does not inspire, its lines of homes huddled just back from the Arctic shoreline, the dust and mud of summer lying heavy over the idle snowmobiles.
It's as if the whole place is waiting for the whitewash of winter. I've come at the warmest time of the year, the peak of the melt season, but even so the temperature only just bobs above freezing.
This is the northernmost town in the United States. It's in a region known as the North Slope but actually it's as flat as a pancake and the wind never slackens.
I nervously wonder whether I've brought enough warm clothes and how I'll cope.
But then we meet our first citizens of this remote spot, only 1300 miles from the North Pole.
Even at the warmest time of year, the climate presents obstacles
A cheery young researcher, a native Alaskan, greets us dressed in jeans and a hoody (though, because this is officially summer, his hood isn't even up).
A smiling taxi driver turns out to be from the tropical Philippines and laughs off any talk of cold.
An Inupiat guide tells us how strongly the community comes together - some young people have left for the big cities but many have not.
It's hard to get my bearings. There are reminders of other remote Arctic communities I've visited - heavy doors to cope with the winter freeze, drying animal skins pinned to racks outside people's homes, elaborate furs framing children's faces, the rattle of quad-bikes.
Also, I should have remembered another feature of many native Arctic villages: the now-widespread ban on the sale of alcohol.
Often, booze has simply caused too much trouble (but it does mean that against the wind chill, I have no ready anaesthetic).
Snowy Owls are well adapted to the icy climes, as are the Alaskan locals
But at the same time Barrow is also very American. In fact we notice a collection of school buses and cars beside the main road and find a crowd gathered for a football game.
The Whalers, the local High School team, are playing at home. If I shut my eyes and listen to the smooth commentary over the PA system I could be in any small town in the US.
But when I look around I see the cheerleaders shivering and Inupiat faces in the team and on the benches.
And just across the road is the ocean that stretches over the top of the world.
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