Scientists predict(预测) that most polar bears will disappear by the year 2100because of global warming. There are about 25,000 polar bears. They spend most of their lives on the ice which covers the Arctic(北冰洋).
As the world gets hotter because of man-made climate(气候)change, the Arctic is warming about twice as quickly as other places. This is making the ice smaller and thinner. Scientists say that by 2040, the ice could melt(融化) completely during the summers. For polar bears, that's a matter of life and death(死亡).
In the winter, when there's ice, polar bears eat as much as possible, to store(贮存) up energy. But these days, there's less winter ice. And summers are the hardest time for polar bears. Because there is less ice to travel on, they have to spend more time on land. But there isn't much food on land.
The scientists believe that by 2040, polar bears will start disappear in southern areas of the Arctic, like Canada. In places like Alaska and Russia, the bears may start to disappear by 2080.
To help save polar bears, It's time for us to take rapid action to reduce the effect(影响）of global heating.
