介绍:
Dragging a sleigh with enough presents for children the world over — not to mention a famously fat white-bearded gentleman — can be not an easy job. But, since ancient times, this Christmas Eve duty has been performed by a team of beloved reindeers.
Soon, however, Santa Claus may have to start looking for a stronger type of animal, as new research has shown that reindeers are becoming thinner. A 16-year survey on the arctic Norwegian island of Svalbard finds that the reindeers there have declined in weight by 12%. And the reduction is being blamed on global warming.
Warmer summers are great for reindeers but winters are getting increasingly tough. Less cold winters mean that snows fall as often as rains that can freeze into a sheet of ice, making it harder for reindeers to reach plant food below. Some reindeers starve and females often give birth to small and weak young.
The number of reindeers has also increased in the past 20 years, meaning that those which are born are facing greater competition for food. So far, we have more but smaller reindeers. And all the weak reindeers will die in winter — the sick, the elderly and babies.
Arctic temperatures are rising faster than the world average due to greenhouse gases in the atmosphere. Scientists say there may well be smaller reindeers in the Arctic in the coming decades, but possibly at risk of dying out because of more ice on the ground.
However, reindeers appear to be suffering less from the effects of climate change than some other arctic animals. Scientists warn that a third of the world’s polar bears could disappear in the next 40 years due to melting arctic sea ice.
