By Sabine Holzer

Unusual incidents are being reported across the Arctic.Inuit（因紐特人）families going off on snowmobiles to prepare their summer hunting camps have found themselves cut off from home by a sea of mud.There are also reports of sea ice breaking up earlier than usual,carrying seals beyond the reach of hunters.Climate change may still be a rather abstract （抽象的）idea to most of us,but in the Arctic it is already having great effects—if summertime ice continues to shrink at its present rate,the Arctic Ocean could soon become almost ice-free in summer.The knock-on effects（連鎖反應(yīng)）are likely to include more warming,cloudier skies，and higher sea levels.Scientists are increasingly eager to find out what's going on in the Arctic.

For the Inuit,the problem is urgent.They live in unsteady balance with one of the toughest environments on earth.Climate change,whatever its cause's is a direct danger to their way of life.Nobody knows the Arctic as well as the locals,which is why they are not content simply to stand back and let outsider experts tell them what’s happening.In Canada,where the Inuit people are trying hard to guard their hard-won autonomy in the country’s newest land,Nunavut,they believe their best hope of survival in this changing environment lies in combining their ancestral knowledge with the best of modern science.This is challenge in itself.

The Canadian Arctic is a vast,treeless polar desert that’s covered with snow for most of the year.Adventure into this area and you get some idea of the hardships facing anyone who calls this home.Farming is out of the question and nature offers few pickings.Humans first settled in the Arctic a mere 4，500 years ago,surviving by taking advantage of sea fish.The environment tested them to the limits:sometimes the settlers were successful,sometimes they failed and disappeared.But around a thousand years ago,one group appeared that was uniquely well adapted to deal with the Arctic environment.These Thule people moved in from Alaska， bringing dogs， iron tools and the like.They are the ancestors of today’s Inuit people.