A. Global warming is causing the Greenland ice cap to disintegrate far faster than anyone predicted. A study of the region's massive ice sheet warns that sea levels may - as a consequence - rise more dramatically than expected. Scientists have found that many of the huge glaciers of Greenland are moving at an accelerating rate - dumping twice as much ice into the sea as five years ago - indicating that the ice sheet is undergoing a potentially catastrophic breakup. The implications of the research are dramatic given Greenland holds enough ice to raise global sea levels by up to 21 feet, a disaster scenario that would result in the flooding of some of the world's major population centres, including all of Britain's city ports. Satellite measurements of the entire land mass of Greenland show that the speed at which the glaciers are moving to the sea has increased significantly over the past ten years with some glaciers moving three times faster than in the mid-1990s.
B. Scientists believe that computer models of how the Greenland ice sheet will react to global warming have seriously underestimated the threat posed by sea levels that could rise far more quickly than envisaged. The latest study, presented at the American Association for the Advancement of Science in St Louis, shows that rather than just melting relatively slowly, the ice sheet is showing all the signs of a mechanical breakup as glaciers slip ever faster into the ocean, aided by the lubricant' of melt water forming at their base.
C. Eric Rignot, a scientist at the Jet Propulsion Laboratory and the California Institute of Technology in Pasadena, said that computer models used by the UN's International Panel on Climate Change have not adequately taken into account the amount of ice falling into the sea from glacial movements. Yet the satellite study shows that about two-thirds of the sea-level rise caused by the Greenland ice sheet is due to icebergs breaking off from fast-moving glaciers rather than simply the result of water running off from melting ice. 'In simple terms, the ice sheet is breaking up rather than melting.
It's not a surprise in itself but it is a surprise to see the magnitude of the changes. These big glaciers seem to be accelerating, they seem to be going faster and faster to the sea,' Dr Rignot said. "This is not predicted by the current computer models. The fact is the glaciers of Greenland are evolving faster than we thought and the models have to be adjusted to catch up with these observations,' he said.
D. The Greenland ice sheet covers an area of 1.7 million sq km - about the size of Mexico - and, in places, is up to 3km thick. It formed over thousands of years by the gradual accumulation of ice and snow but now its disintegration could occur in decades or centuries. Over the past 20 years, the air temperature of Greenland has risen by 3*C and computer models suggested it would take at least 1,000 years for the ice sheet to melt completely. But the latest study suggests that glaciers moving at an accelerating rate could bring about a much faster change. The behaviour of the glaciers that dump ice into the sea is the most important aspect of understanding how an ice sheet will evolve in a changing climate,'
Dr Rignot said. It takes a long time to build and melt an ice sheet but glaciers can react quickly to temperature changes. Climate warming can work in different ways but, generally speaking, if you warm up the ice sheet, the glacier will flow faster,' he said.
E. The ice 'balance sheet' of Greenland is complex but - in simple terms - it depends on the amount of snow that falls, the amount of ice that melts as run-off and the amount of ice that falls directly into the sea in the form of icebergs 'calving' from moving glaciers.Satellites show that the glaciers in the south of Greenland are now moving much faster than they were ten years ago. Scientists estimate that, in 1996, glaciers deposited about 50 cubic km of ice into the sea. In 2005 it had risen to 150 cubic km of ice. Details of the latest study, published in the journal Science, show that Greenland now accounts for an increase in global sea levels of about 0.5 millimetres per year - compared to a total sea level rise of 3mm per year. When previous studies of the ice balance are taken into account, the researchers calculated that the overall amount of ice dumped into the sea increased from 90 cubic km in 1996 to 224 cubic km in 2005.
F. Dr Rignot said that there are now signs that the more northerly glaciers of Greenland are beginning to adopt the pattern of movements seen by those in the south. The southern half of Greenland is reacting to what we think is climate warming. The northern half is waiting, but I don't think it's going to take long,' he said.
| A | B | C | ||
|---|---|---|---|---|
| 1 | Glaciers react very quickly to temperature variations. | |||
| 2 | If glaciers move more quickly sea levels could rise much more rapidly. | |||
| 3 | Predictions have miscalculated the speed at which sea levels will rise. | |||
| 4 | Between 1996 and 2005 the amount of ice deposited into the sea increased from 50-150 cubic km. | |||
| 5 | Calculations have not included the ice that falls into the sea as icebergs. | |||
| 6 | The northern part of Greenland is going to behave in the same way as the south. |
AI explanationShows the answer. Tap to open.
Question Focus: Synonym match - 'react very quickly' = 'can react quickly'
Why this is correct: The answer is Eric Rignot because he directly explains glacier behaviour. He says that while ice sheets take a long time to change, glaciers can react quickly to temperature changes, which is exactly what the statement says.
Passage Reference: It takes a long time to build and melt an ice sheet but glaciers can react quickly to temperature changes.
Common Mistake: Many students choose scientists because scientists are mentioned often. This is a Context shift trap because this specific idea is said by one named person, not scientists in general.
Paraphrasing: Passage: 'glaciers can react quickly to temperature changes' = Statement: 'react very quickly to temperature variations'
Tips: When a sentence is inside quotation marks, check who is speaking. Matching Features often depend on who says the idea.
Key Vocabulary:
- react = respond
- variations = changes
Question Focus: Causation link - faster glacier movement = faster sea level rise
Passage Reference: Scientists believe that computer models of how the Greenland ice sheet will react to global warming have seriously underestimated the threat posed by sea levels that could rise far more quickly than envisaged. The latest study, presented at the American Association for the Advancement of Science in St Louis, shows that rather than just melting relatively slowly, the ice sheet is showing all the signs of a mechanical breakup as glaciers slip ever faster into the ocean
Why this is correct: The answer is the most recent report on the Greenland ice sheet because the study explains the connection. It says that sea levels could rise far more quickly because glaciers are slipping ever faster into the ocean.
Common Mistake: Some students choose Eric Rignot because he talks about glacier speed. This is a Wrong section trap because this cause-effect link is explained in the study report, not his personal comments.
Paraphrasing: Passage: 'sea levels could rise far more quickly' = Statement: 'sea levels could rise much more rapidly'
Tips: Look for cause and effect language like 'as a result' or 'could lead to'. These often signal report findings.
Key Vocabulary:
- rapidly = quickly
- slip = move
Question Focus: Synonym match - 'miscalculated' = 'underestimated'
Passage Reference: Scientists believe that computer models of how the Greenland ice sheet will react to global warming have seriously underestimated the threat posed by sea levels that could rise far more quickly than envisaged.
Why this is correct: The answer is scientists because this view is described generally. The passage says computer models have seriously underestimated how quickly sea levels could rise.
Common Mistake: Students sometimes choose the most recent report. This is a Partial truth trap because the report is mentioned, but the belief is clearly attributed to scientists overall.
Paraphrasing: Passage: 'seriously underestimated' = Statement: 'miscalculated'
Tips: Words like 'believe' or 'think' often show opinions held by a group such as scientists.
Key Vocabulary:
- underestimated = guessed too low
- envisaged = expected
Question Focus: Exact figure match - dates and numbers
Passage Reference: Scientists estimate that, in 1996, glaciers deposited about 50 cubic km of ice into the sea. In 2005 it had risen to 150 cubic km of ice.
Why this is correct: The answer is scientists because they are the ones who calculated these figures. The passage clearly gives the numbers 50 cubic km in 1996 and 150 cubic km in 2005.
Common Mistake: Some students choose the most recent report because the data comes from a study. This is a Context shift trap because the sentence starts with 'Scientists estimate'.
Paraphrasing: Passage: 'Scientists estimate... 50 cubic km... 150 cubic km' = Statement: 'increased from 50-150 cubic km'
Tips: For number questions, slow down and match years and figures exactly. IELTS often tests precision.
Key Vocabulary:
- deposited = put into
- estimate = calculate
Question Focus: Reverse meaning awareness - models did not take into account
Passage Reference: Eric Rignot, a scientist at the Jet Propulsion Laboratory and the California Institute of Technology in Pasadena, said that computer models used by the UN's International Panel on Climate Change have not adequately taken into account the amount of ice falling into the sea from glacial movements.
Why this is correct: The answer is the most recent report on the Greenland ice sheet because it explains what models failed to include. It says calculations have not adequately taken into account ice falling into the sea from glaciers.
Common Mistake: Many students choose Eric Rignot because he is named. This is a Wrong focus trap because he is reporting what the models missed, not giving a personal opinion.
Paraphrasing: Passage: 'have not adequately taken into account' = Statement: 'have not included'
Tips: Do not match based on names only. Ask yourself who owns the idea, a person or a report.
Key Vocabulary:
- adequately = properly
- calving = breaking off
Question Focus: Future prediction - same pattern of movement
Passage Reference: Dr Rignot said that there are now signs that the more northerly glaciers of Greenland are beginning to adopt the pattern of movements seen by those in the south. The southern half of Greenland is reacting to what we think is climate warming. The northern half is waiting, but I don't think it's going to take long,' he said.
Why this is correct: The answer is Eric Rignot because he predicts future behaviour. He says the northern glaciers are beginning to adopt the same pattern as the south.
Common Mistake: Some students choose scientists. This is a Future assumption trap because this prediction is made by one individual, not scientists as a group.
Paraphrasing: Passage: 'adopt the pattern of movements seen by those in the south' = Statement: 'behave in the same way as the south'
Tips: Predictions often belong to one speaker. Look for 'he said' or 'she said' carefully.
Key Vocabulary:
- adopt = start using
- pattern = way of behaving
General Tips:
- Matching Features can jump around the passage, so do not assume answers follow paragraph order.
- Scan for names like Eric Rignot first. They are strong anchors for matching.
- Options CAN be used more than once, so never cross them off after one use.
- Pay attention to who is speaking. Reports, scientists, and individuals often give different types of information.
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