By Richard Hollingham
BBC News, Greenland
Greenland's ice is melting rapidly. In some places, glacial levels have been falling by 10 metres a year and ultimately contributing to rising sea levels. Travelling to Greenland, Richard Hollingham sees the impact of climate change for himself.
If it reaches the ocean, the glacial water will increase sea levels
The gleaming white executive jet taxied to a stop on the cracked concrete apron beside a couple of derelict hangars.
Beyond the rusty barbed wire and crude prefabricated buildings surrounding the airport perimeter, cliffs of dark granite rose from the valley to blend with the equally ominous grey of the sky.
No trees, no colour, no signs of life.
The door of the private plane swung down.
Onlookers, had there been any, might have caught a glimpse of the deep leather seats and walnut panelling of the interior.
Perhaps a group of sharp suited executives would emerge looking dynamic and business-like. Or perhaps some sinister men-in-black types, here on covert government business.
The first person to climb down was wearing oversized shorts, stout walking boots and a hat that looked like it had seen rather more of the world than it was perhaps designed for.
The next man was dressed in a clashing array of outdoor clothing and sported large tortoise-shell glasses and an unkempt beard.
Its enormous ice cap, a sea of white stretching seemingly forever, overflows into thousands of glaciers
Each man muttered something about the landscape being bleak.
I would like to be able to tell you that when the BBC descended from the plane we stood apart with our sartorial elegance.
But if you have ever met any BBC types, particularly radio reporters, you would know that would be a lie.
We had landed at Kangerlussuaq, a community whose existence depends solely on the airstrip.
This used to be a bustling US base, servicing America's early warning system.
These days it is somewhat self perpetuating. The airport brings in supplies for the people who live here who mostly work at the airport.
I was tagging along with a group of eminent scientists, funded through the foundation of a billionaire philanthropist, Gary Comer. He has devoted his retirement to the science of global warming.
The researchers all make regular visits to the Arctic to assess the impact of climate change, not, it should be said, always in such comfort.
Greenland is a massive island locked in ice. And from the air there is little evidence that it is melting.
Retreat: As air temperatures rise, glacial recession increases
Its enormous ice cap, a sea of white stretching seemingly forever, overflows into thousands of glaciers.
These in turn carve their way through the mountains to the coast.
It is only when you get near to the base of the glaciers that you can see how the landscape is changing.
A few metres above the ice, the rock is totally bare. A scar running horizontally across the valleys.
It is as if the ice has been drained away, like water in a bath, to leave a tide mark. Which is, in effect, what has happened.
The ice has melted and the glaciers have retreated hundreds of metres over the past 150 years.
The weather cleared and with the edge of the glacier, a giant wall of ice behind us, glaciologist Richard Alley led me across the barren rock.
As I tripped and stumbled behind him, he bounded through scree and leapt over crevasses.
This land was being exposed for the first time in millions of years
I have never seen a scientist more in his element as he pointed out deep grooves in the rock where the ice had raked the stone, or the giant boulders lifted by the glacier to balance precariously on top of tiny pebbles.
This land was being exposed for the first time for millions of years. Even a century ago, where I stood would have been solid ice, and I was struck by just how much vegetation there was.
Phillip, the biologist on the trip, was every bit as excited as Richard, identifying the dark brown lichens on the rocks, the grasses and beautiful purple flowers somehow managing to cling to just a few millimetres of soil.
The Earth's climate has warmed before, albeit naturally.
A ruined church on the banks of a fjord marks the remains of a Viking farming civilisation.
The sun casts shadows through the arched window to the site of the altar, last used in the 1400s before the area was abandoned when it became too cold to support habitation.
Today, the farmers are back.
Sheep once again graze the surrounding hillside and shiny new tractors work the fields near the southern coast.
Greenland is turning green, something the rest of us should be very worried about indeed.
From Our Own Correspondent was broadcast on Saturday, 13 August, 2005 at 1130 BST on BBC Radio 4. Please check the programme schedules for World Service transmission times.