总统奥巴马在月初总统选举结束后首次会面共和党对手米特·罗姆尼,他们在白宫进行午餐,奥巴马开始履行自己在获胜演讲中与共和党合作的承诺。
A major new study in the polar ice sheets has discovered that the rate of melting has accelerated in the past 20 years. David Shukman is our science correspondent.
有关极地冰原的重大研究表明,冰原的融化速度在过去20年间已经加速。科学记者David Shukman报道。
Remote, vast and inaccessible, the ice sheets covering Greenland and Antarctica are extremely difficult to measure. But by comparing readings from different satellites, researchers have come up with a single estimate for the rate at which the ice has been melting into the ocean. Over the past twenty years, they say, melting is added about 11mm to the global sea level. And crucially, they found that this loss of ice is accelerating. Greenland is losing ice the fastest. Western Antarctica is also shedding some, but eastern Antarctic is gaining ice while it remains well below zero.
格陵兰和南极的冰原位置偏远、广大、难以接近,因此很难评估。但研究者通过对比不同卫星的读数,已对冰原融化后流入海洋的速度进行了简单的估计。研究者称,在过去20年间,融冰使海平面上升了11毫米。更重要的是,他们发现冰原消失的速度也在加速,格陵兰的冰消失得最快,南极西部也在失去一些冰块,但南极东部的冰却在增加,仍远低于零。