The heating of the planet is pushing Earth’s polar bear population to its limit, and according to a new study, they could have fewer than 100 years left before extinction.
The polar bears live by hunting seals in the Arctic Ocean, but as more and more ice melts (融化) in that region, their habitat continues to reduce. Since amounts began to be measured at the end of the 1970s, sea ice that lasts for more than a year in the Arctic has decreased at a rate of 13% per decade.
Studies have long shown that declining sea ice will lead to a decline in polar bears, but new research published in Nature Climate Change models a specific doomsday (世界末日) timeline. Polar bears will be unable to endure the effects of climate change over the next several decades, the scientists believe, and will be wiped out by 2100.
“What we’ve shown is that, first, we’ll lose the survival of cubs (幼崽), so cubs will be born, but the females won’t have enough body fat to produce milk to bring them along through the ice-free season, said Dr. Steven Amstrup, chief scientist of Polar Bears
International, to the BBC. “Any of us know that we can only go without-food for so long. That’s a biological reality for all species.”
The study estimated that, even in a situation where countries achieve a moderate (适中的) reduction in greenhouse gases, several populations of polar bears will disappear. But Amstrup emphasized that the animal can still persist (坚持) if climate change does not continue.
“Showing how imminent (迫在眉睫的) the threat is for different polar bear populations-is-another reminder that we must act now to head off the worst of future problems faced by us all,” he said. “The course we’re on now is not a good one, but if society gets its act together, we have time to save polar bears. And if we do, we will benefit the rest of life on Earth, including ourselves.”
【小题1】In writing Paragraph 1, the author aims to________.| A．present an argument | B．make a comparison |
| C．propose a definition | D．introduce a topic |
| A．Seals hunt polar bears for food. |
| B．The sea ice has decreased by 13% in a year. |
| C．Polar bears depend on sea ice for their survival. |
| D．More and more seals are leaving the Arctic Ocean. |
| A．Sea ice will be wiped out by 2100. |
| B．The doomsday for mankind is coming. |
| C．Newborn bears will starve to death in the coming decades. |
| D．Polar bears will eventually be able to survive without sea ice. |
| A．we must act now to save ourselves |
| B．reducing greenhouse gases is good for all living things on Earth |
| C．the polar bear population is an imminent threat and we must take action |
| D．we should stay on our current course for the survival of all living things |
| A．How do polar bears survive? |
| B．Arctic sea ice is melting at an accelerating rate. |
| C．Polar bears and humans should coexist in harmony. |
| D．Polar bears could be extinct by end of the century. |
