I refer, of course, to that distinctive arctic plant eater, the musk ox (Ovibos mochatus) with its famously warm longhaired coat.

There are 103 of these shaggy beasts in this valley, or at least there were yesterday when Toke Thomas Hoye counted them. He's a PhD candidate with the University of Copenhagen, working at the station this summer, and musk ox counting is part of the job.

"I start on that small hill," he explains pointing at a hill some ways off. "From there I can see where the herds are and plan my walk." The walk covers a roughly 19-mile (30km) circuit through the valley, and at times there are almost 200 musk oxen in the valley - a healthy population level.

Today, Toke grabs his gear and we walk a short way past the airstrip to where a couple of older males are grazing. Toke uses binoculars and a tripod mounted spotting scope to count the musk oxen and classify them by age and sex. He can tell these are older males from the shape and size of their horns. When they're calves both genders look the same, but by the time they're a year old, males have small pointy horns coming straight out the sides of their heads and a lot of white wool in the middle of their forehead.

Global warming and musk ox

For Toke, the challenge of looking at the ecosystem as a whole is much more interesting than focusing on one species.

He stresses that because so many of the variables are interlinked the overall effect of global warming is difficult to predict.

What's more, there are still a lot of questions about musk ox behavior, and other variables, in the winter. The science station operates only in the summer, and research here in the winter would be a major logistical challenge, requiring funding they simply don't have.

What happens in the winter is an especially important part of the puzzle when it comes to musk ox because, as Toke described it, winter is the "survival bottleneck" for the animals. It's known that musk ox numbers in northeast Greenland can vary greatly from year to year. These changes in population seem to coincide with changes in winter temperatures, and oddly enough, warmer isn't necessarily better.

As Toke explained, "We have graphs in our mess room where the temperature declined nicely over winter, and then suddenly there was this blip of positive temperatures over a day or so and then it dropped back again." In fact, temperatures of 11 degrees Centigrade (52° F) were recorded for several hours in February this year. In general, this sort of thing is not a new phenomenon, but this year was the first time temperatures above freezing have ever been recorded in February.

You'd think in a place where the temperature gets down to -40 degrees Centigrade (-40° F), a few days of warmer weather would be a welcome development for the musk oxen. But the snow melted by the brief thaw soon refroze into a thick layer of ice - covering the ground vegetation that the musk ox depend on for food.

Winter is already the hardest time of the year for these animals, and many calves don't live through their first. If these ice crust episodes become more frequent it could spell disaster for the musk oxen here.

Going, going, gone

Almost half a mile away, two musk oxen see us and bolt - heading off at a good pace. We follow parallel to their course, but more slowly.

At the top of the next rise, they stop and face each other. "Have a look now, they might have a fight," says Toke. Sure enough, they run at each other and clack heads. After a brief shoving match, they walk on. This behavior was puzzling because there are no females around to impress. Toke thought it might have been a sort of stress relief response to being spooked. Soon we give up following. "Once they start to move, they move for a while," he explains.

Watching the musk ox jog off into the distance, I realize that what we have here is an allegory. Once you provoke a response, you sometimes can't control what happens next. And, small actions can have big consequences. All we did was cross an imaginary line, almost half a mile from the musk oxen. The difference between them ignoring us, and them running, was only a matter of a few steps across that line, but there was no way to know exactly where that line was until we crossed it.

The same could be said for global warming. If we keep adding greenhouse gasses to the atmosphere, at some point we might cross a line where feedback effects take over - continuing to heat up our planet no matter what we do from there on.

Of course, this is just an allegory. Reality is more complex. In reality, global warming is already happening - it's only a question of how far it will go, how much damage it will do and how much we can slow it down. In reality, there are also ways to move forward (renewable energy and energy efficiency) without changing the climate.

But the reality is also that business continues as usual, unless we make a real effort to change it.

- Andrew