高中英语 Unit 6 Earth first Section Ⅰ Starting out Understanding ideas教学案 外研版必修第二册-外研版高一第二册英语教学案

Unit 6 Earth first 科学家警告：北极海冰的加速融化会造成不可控制的全球气候变化。Melting Arctic Sea Ice Could Start Uncontrollable Global Climate ChangeThe rapid melting of the Arctic sea ice could be about to bring about catastrophic( 灾 难 性 的 ) events across the world, scientists have warned.The effects of the melting ice could be felt as far away as the Indian Ocean as the warm weather sets off 19 global tipping points( 临 界 点 ), according to the new Arctic Resilience Report. Those tipping points happen when a natural system quickly changes, leading to great effects on nearby ecosystems that might never be reversed(彻底转变)．In the Arctic, they include growing vegetation that stops snow and ice and so absorbs more heat, and the release of methane( 甲 烷 ) from the Arctic as it warms. The report includes a range of different disastrous events that are likely to be produced by the warming poles.The findings come just as climate scientists have warned that sea ice in the Arctic appears to be melting far more quickly than expected as the result of high temperatures.Air over the Polar ice cap has been 9－12 degrees Celsius above average over the last four weeks, according to the Danish Meteorological Institute(DMI) ． Through last week, temperatures reached melting point, putting them far above the expected temperature and serving as a dangerous signal for the sea ice there.The temperature is “by far the highest recorded” ， DMI researcher Martin Stendel told the AFP.“What we are observing is very unusual.”At this time of year, the Arctic Ocean would be expected to start freezing up into sea ice again. But it isn’t happening.“Not only was the ice not growing as it would normally, th...