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140 Climate 11 LANGUAGE SKILLS EXPLORE EXTRAS Read the rest of the article quickly. What seems to be happening in Greenland? Do scientists fully understand it? a 17  Now it is melting, far faster than the climate models predicted and far more decisively than any political action to fight our changing climate. If the Greenland ice sheet disappeared, sea levels around the world would rise by seven metres, as 10% of the world’s fresh water is currently frozen here.  Experts fromaround theworld are landing on the ice sheet in a race against time to discover why the ice in Greenland is vanishing so much faster than expected. Gordon Hamilton, a Scottish- born glaciologist, hit upon the daring idea of landing on a moving glacier in a helicopter to measure its speed. When Hamil- ton processed his first measure- ments of the glacier’s speed, he found it was marching forwards at a greater pace than a glacier had ever been observed to flow before. “We were blown away because we realised that the glaciers had accelerated not just by a little bit but by a lot,” he says. The three glaciers they studied had abruptly increased the speed by which they were transmitting ice from the ice sheet into the ocean.  Driven by the loss of ice, Arctic temperatures are warming more quickly than other parts of the world: last autumn air tempera- tures in the Arctic stood at a record 5 °C above normal. For centuries, the ice sheets main- tained an equilibrium: glaciers calved off icebergs and sent melt water into the oceans every summer; in winter, the ice sheet was then filled up again with more frozen snow. Scientists believe the world’s great ice sheets will not completely disappear for many more centuries, but the Greenland ice sheet is now shedding more ice than it is accu- mulating.  Research is focusing on what scientists call the ‘dynamic effects’ of the Greenland ice sheet. It is not simply that the ice sheet is melting steadily as global temperatures rise. Rather, the melting triggers dynamic new effects, which in turn accelerate the melt. “It’s quite likely that these dynamic effects are more important in generating a rapid rise in sea level than the tra- ditional melt,” says Hamilton. Some scientists are astounded by the changes. “We can’t as a scientific community keep up with the pace of changes, let alone explain why they are happening,” says the glaciologist. Read the article more carefully. In pairs, summarise what the author says about: b Read the information in the box. We can use the present progressive to describe: a gradual ongoing processes (= it’s happening all the time). b temporary situations and activities (= it’s happening around now). Now look at examples a–e from the previous sections. 1 Which use of the present progressive do the sentences show? 2 Which uses the passive? a Climate change is being experienced everywhere in the world. b One scientist is proposing to put a huge glass sunshade into space. c Richard Branson is offering $25 million. d Experts from around the world are landing on the ice sheet. e Arctic temperatures are warming more quickly than in other parts of the world. Look at The Sermilik fjord in Greenland again. Which examples of the present progressive can you find? a LanguagE FOcus 18 Present progressive active and passive b 1 the Greenland ice sheet 2 Gordon Hamilton 3 air temperatures 4 ‘dynamic effects’ Nur zu Prüfzw cken – Eigentum des Verlags öbv