Global Warming
A The Stern Review Report on The Economics of Climate Change, published in 2006, the same year as Al Gore’s highly-acclaimed film and book, An Inconvenient Truth, made it clear that governments need to take the issue of global warming very seriously indeed. The Stern Review examined the issue of climate change from an economic perspective, looking at what it would cost the government to take appropriate action, and what it would cost if appropriate action were not taken. The report also highlighted a number of catastrophes that would occur if urgent measures were not taken to stop the carbon dioxide production that is heating up the planet. The report indicates that in the last 200 years, average temperatures on the planet have increased by less than one degree Celsius; however, if we do not control the rising carbon dioxide levels over the next 100 years, a rise of up to five degrees Celsius can be expected. This will have an enormous impact on global economic growth and will cause many potentially disastrous changes, including the following:
B Melting glaciers—Beginning in the Andes, and then extending to the huge glaciers of the Himalayas, the ice will begin to disappear, threatening the water supply of billions of people. Sea levels will also rise, flooding huge areas of the world, including cities such as London and Tokyo.
C Melting ice sheets—Not only will glaciers melt, but as the planet warms up, the huge Antarctic Ice Sheets and the floating sea ice of the Arctic will begin to melt, again resulting in catastrophic rises in sea levels. It is estimated that Arctic summers will be ice-free within 10 years, and the landscapes of the Antarctic will change beyond recognition by 2050. The vast ice plains of Greenland are also under threat.
D The acidity resulting from the huge amounts of CO2 that the oceans will absorb will lead to the extinction of hundreds of species as marine ecosystems are destroyed; this will also threaten the fishing industry as thousands of millions of fish die off. This in turn will destroy the livelihood of thousands of fishing communities that depend on already overfished coastal areas.
E Accompanying the floods will be an increasing occurrence of droughts, with a decrease of up to 30% in water availability in Africa, and similar decreases in Australia. This will, of course, result in crop failure and malnutrition the world over. It will also lead to an increase in disease, particularly in tropical regions. Large cities in dry regions will find it increasingly difficult to provide enough water for their populations.
F Hurricanes, cyclones and tidal waves—Both A1 Gore’s book and the Stern Review indicate that if global temperatures continue to rise, we can expect a greater number of extreme weather phenomena, of an increased severity. Hurricane Katrina, which devastated the United States in 2005, is cited as just one example of the kind of environmental and economic havoc that will result from unchecked global warming. Typhoons, which often cause extensive flooding, are becoming more frequent and devastating in South East Asia.
G Up to 50% of animal and plant species on the planet, beginning with those living in fragile environments such as coral reefs, tropical rainforest and alpine tundra, will become extinct. Climate change will eventually affect every ecosystem on the planet as temperatures increase, rainforest is destroyed and sea levels rise, leading to flooding and drought. The impact on ecosystems will be so dramatic that they will never recover from the damage caused by rising temperatures.
H Does all this sound too depressing even to contemplate? Well, don’t despair: if you are optimistic by nature, there are two approaches to tackling the problem of global warming you could take.
I The first approach is to begin to act locally to do your bit to reduce CO2 emissions and minimise pollution, at the same time hoping that governments will listen to the recommendations of the Stern Review, which, while recognising the seriousness of the threat, clearly indicates that if action is taken now, the right balance between economic growth and environmental conservation may be achieved. The Report is significant, both in its scope and its depth, and it does offer a positive outcome that allows economic growth to continue—so perhaps this will convince governments to take the action necessary to save the planet from environmental and economic disaster.
J The second approach you could take, if you wish to remain optimistic, is to disregard the warnings of A1 Gore, the Stern Review team and other like-minded harbingers of doom, and instead opt for the much more positive and less dramatic stance taken by a very different group of scientists and economists. With its nominal leader the Danish economist, Bjorn Lomborg, the Omgivelse group believes that many of the predictions of the environmentalists are hugely exaggerated. Like Stern, Lomborg takes a pragmatic economic approach to the environmental situation and argues for investment in environmental research and development, rather than quick-fix’ measures that would not, he claims, solve the problem. With significantly less investment than that recommended in the Kyoto Accord or by the Stern Review Report, Lomborg believes the planet can be saved.
Questions 1-3
Complete the summary below. Choose NO MORE THAN THREE WORDS from the passage for each answer.
The Stern Review Report emphasised the (1)…………………….to assess seriously the problem of global warming from (2)…………………………..point of view. It also focused on a number of environmental (3)…………………….that would happen if governments do not act to prevent climate change.
Questions 4-12
Reading Passage 1 has ten paragraphs, A – J. Choose the most suitable heading, i – xiii, for each paragraph from the list of the headings below. Write the correct numbers, i – xiii, next to Questions 4-12.
List of headings
i Long term solutions
ii A balancing act
iii Killing wildlife
iv Extreme weather
v Water crisis
vi Endangering sea life
vii Sinking cities
viii Intensive farming
ix Trouble at the poles
x Alarming studies
xi Two outlooks
xii Arctic wildlife
xii Burning coal
Example: Paragraph H Answer xi
4 Paragraph A
5 Paragraph B
6 Paragraph C
7 Paragraph D
8 Paragraph E
9 Paragraph F
10 Paragraph G
11 Paragraph I
12 Paragraph J
Questions 13 and 14
Complete each of the following statements with the best ending, A – H, from the list of endings below.
Write the correct letters, A – H, next to Questions 13-14.
13 The Stern Review points out that it is not too late……………………….
14 More optimistic commentators like Bjorn Lomborg believe that politicians and scientists need………………..
List of endings
A to sign international environmental treaties
B to strike the balance between economy and environment
C to take personal responsibility for reducing CO2 emissions
D to stop exaggerating the issue
E save the planet
F to find a solution to the problem
G the issue of global warming
H the problem of water pollution
Cure-All Pills: Myths Or Reality?
Browse the shelves of any health food shop or pharmacy and you’ll find dozens of dietary supplements—vitamins, antioxidants, minerals—along with a seemingly endless range of homeopathic remedies. There is always something new, some ‘miracle ingredient’ offering the promise of a longer, healthier, happier life. There are extracts of every kind of fruit and vegetable you can imagine—tomato, celery, carrot, papaya and cranberry—along with green tea potion, red wine extract and vitamins A-K in every colour and form. And all of these supplements claim to assist us in the constant battle against ageing, cancer, cardio-vascular disease, and a cornucopia of other afflictions. However, recent research may show it is all too good to be true.
So how real are these claims? Vitamin tablets have been around forever, but antioxidants are the latest miracle cure; the question is, do they work? If the hype is true, then what antioxidants do is work to neutralise the free radicals in our bodies and later excrete them. Free radicals are atoms or molecules that have at least one unpaired electron and are therefore unstable and highly reactive. In animal tissue they are believed to accelerate the progression of cardio-vascular and age-related diseases, such as dementia and cancer. Antioxidants in fresh fruit and vegetables have been shown to combine with free radicals and neutralise them, preventing the oxidation which may lead to disease.
An apple a day keeps the doctor away’—if eaten alongside four other portions of fresh fruit and vegetables! It is clear that those who eat more fruit and vegetables—and the recommended daily intake is at least five portions—are less prone to disease and live longer, healthier lives. Over the last 20-30 years, scientists have worked to isolate the active ingredients in fruit and vegetables— believed to be the antioxidants—and have conducted controlled tests of antioxidants, which revealed that they do indeed appear to have the ability to halt some of the chemical processes that cause disease. Thus the multimillion dollar industry of bottled antioxidants to supplement the diets of the busy and the stressed was born.
Antioxidants were first cast into doubt during a major clinical trial in the US, in which a very common antioxidant, beta-carotene, also known as pro-vitamin A (found in yellow and green vegetables, milk and fish), was being tested for its efficacy against lung cancer in high-risk subjects. To the surprise and concern of the scientists conducting the experiment, those individuals taking the supplement—intended to reduce the risk of cancer—were at a significantly higher risk of developing lung cancer. This startling discovery led to the abandonment of the trials mid-way through the experimental process.
Since this experiment in the mid-90s, other studies have similarly indicated that antioxidants and vitamin supplements are of dubious health value at best, and may possibly be harmful. It seems that even common vitamin supplements such as vitamin C may, in large doses, actually exacerbate the risk of cardio-vascular disease or cancer.
As a result of these recent alarming studies, the US Food and Drug Administration (FDA) and its European equivalent, the European Medicine Agency (EMEA), have taken the decision to prohibit the production and sale of a number of the higher-dose supplements currently on the market.
Another aspect of the increasingly complex picture to take into account is that recent research findings have also called into question some previously held beliefs concerning free radicals. It is possible, some scientists believe, that free radicals actually play a role in preventing disease. Professor Jennifer Horton at the University of West Wyoming is one of a number of scientists who has found that in small amounts, the free radicals may help stimulate the antioxidant systems in our bodies. It is also becoming apparent that free radicals may play a fundamental role in the fight against disease; recent research in the UIC suggests that they kill off harmful bacteria and even cancerous cells.
Clearly, then, the use of bottled supplements with your diet is a practice to approach warily; and it is essential to keep abreast of new developments in research. Ironically, those health-conscious individuals who already eat large quantities of fresh fruit and vegetables, whose diet does not include junk food and who get plenty of regular exercise and have less need for dietary supplements tend to be the ones who are most likely to use them.
Questions 15-18
Choose the correct letter A, B or C.
15 When introducing his discussion on antioxidant diet supplements, the writer notes that
A most supplements sold in pharmacies or health food shops have at least some proven health benefits.
B very few diet supplements are regulated by government health agencies.
C there is evidence that some dietary supplements can be bad for your health.
D only a few products offer real protection against ageing, heart disease and cancer.
16 In the fourth paragraph, the writer’s main point is that
A very high doses of antioxidant supplements can harm the liver.
B US doctors prescribe pro-vitamin A to patients.
C the clinical trials did not produce any conclusive results.
D antioxidant supplements can increase the risk of some cancers.
17 According to the writer,
A recent studies have confirmed the benefits of antioxidants.
B vitamin C supplements help to decrease the risk of heart disease.
C the European Union endorses some higher-dose vitamin supplements.
D some governments have banned a number of higher-dose vitamin supplements.
18 The writer suggests that
A it is better to take vitamin supplements than not to take them.
B it is important to be well-informed about vitamin supplements before taking them.
C people who exercise regularly should supplement their diets with vitamins.
D vitamins and antioxidants are less effective when consumed as food.
Questions 19-24
Do the following statements agree with the information in Reading Passage 2?
Next to Questions 19-24, write
TRUE if the statement is true according to the passage
FALSE if the statement is false according to the passage
NOT GIVEN if the information is not given in the passage
19 Vitamin supplements bought from health food shops can differ from those available at pharmacies.
20 Antioxidants eliminate free radicals from the body.
21 After the release of Professor Horton’s study the number of people taking vitamin supplements declined.
22 The findings of studies into the effect of pro-vitamin A resulted in some US drug companies going on trial.
23 The FDA and the EMEA have jointly funded research into the safety of certain higher-dose vitamin supplements.
24 Recent research suggests that small amounts of free radicals can help prevent disease.
Questions 25-29
Complete the sentences below with words taken from Reading Passage 2. Use NO MORE THAN THREE WORDS for each answer.
25 Professor Jennifer Horton says that small amounts of………………………may be beneficial for our bodies.
26 Some studies have indicated that vitamin supplements can be………………….
27 Free radicals may have an important function in………………………
28 ……………………………..people tend to be the ones who use bottled supplements.
29 You should……………………….the use of bottled vitamin supplements with caution.
Water And Chips Break New Ground
Computers have been shrinking ever since their conception almost two centuries ago, and the trend is set to continue with the latest developments in microchip manufacturing. The earliest prototype of a mechanical computer was called the Difference Engine, and was invented by an eccentric Victorian called Charles Babbage. It weighed over 15 tons and had 26,000 parts. Colossus, the first electronic computer, did not appear until the end of WWTI, and with its 1,500 vacuum tubes was even more complex and much heavier than its mechanical predecessor.
It was only when the silicon-based microchip was invented in the early 1950s that computers started to become more compact. The first microchip computers were very complex and had more than 100,000 transistors, or electronic switches; however, they were still rather bulky and measured several metres across. Nowadays microchips are measured in nanometres (nm)—that is, in billionths of a metre—and the search for even smaller microchips continues as scientists work on new methods of microchip production.
Today, most microchips are shaped by a process called lithographic etching, which uses ultraviolet (UV) light. A beam of UV light with a wavelength of only 193 nm is projected through a lens on to an etching mask, a micro device with slits, or long narrow cuts. When the UV light hits the surface of silicon chips, it removes microscopic layers of silicon to create patterns for the microchips circuits. Microchips with features as small as 65 nm can be created with this wavelength.
However, lithographic etching is unable to make chips much smaller than 65 nm due to the fundamental properties of light. If the slit in the mask were made narrower, the air and nitrogen used in the space between the lens and the etching mask would diffuse the light, causing a blurred image. This means that 193-nm UV light cannot be used to produce microchips with features smaller than 65 nm. Manufacturers know that they need to go even smaller for the technological demands of this century, and they are looking for new methods of making microchips.
One approach to solving the problem is to use microscopic mirrors to focus X-rays rather than ultraviolet light. X-rays with a wavelength of less than 25 nm can be created, allowing engineers to make components smaller than 15 nm. The process is known as X-ray lithography etching. However, this technology is extremely expensive, so manufacturers are continuing to search for a cheaper alternative.
A technology called immersion lithography might be the solution. Although liquids are not commonly associated with computers, a tiny drop of water may be all it takes to make microprocessors smaller and more powerful. Intel and IBM, who made the first microprocessors, have recently developed a unique method of microchip production, which uses water droplets to enable manufacturers to shrink the chips—and at a reasonable price! The new microchip is produced by using a drop of water to narrow the gap between the light source and the etching mask, and shorten the wavelength of the UV light to less than 34 nm. This process can be used to manufacture microchips as small as 45 nm, or possibly even smaller.
Initially, engineers feared that air bubbles and other contaminants in water drops would distort the light and ruin the microchip etching process, and the first experiments proved these fears to be well-founded. The problem was overcome by using high-purity water, free of air and other substances. Scientists are also experimenting with liquids other than water—denser liquids such as hydrofluoric acid—which may allow the wavelength to be shrunk still further, thus producing even smaller chips.
IBM have already successfully implemented immersion lithography on some of their production lines and created a fully-functioning microprocessor. IBM also claim that they are able to produce microchips with very few defects.
Although immersion lithography is very new, it is highly promising as it will make the production of 45 nm and 32 nm chips commercially viable. It is a significant milestone in chip manufacturing and will help to bring the costs of the chip down without fundamentally changing the microchip production processes.
In the near future, the ground-breaking technology of immersion lithography will enable computer manufacturers to make powerful microchips that will be used in electronic devices smaller than a coin. This will open up new opportunities in the ever-shrinking world of digital technology.
Questions 30-34
Do the following statements agree with the information given in the reading passage? Next to Questions 28-32, write
TRUE if the statement is true according to the passage
FALSE if the statement is false according to the passage
NOT GIVEN if the information is not given in the passage
30 The first electronic computer weighed more than the first mechanical prototype.
31 Computers started to shrink with the invention of the microchip.
32 In early 1950s engineers used ultraviolet rays to build the first microchip.
33 X-ray lithography is an inexpensive alternative technology to lithographic etching.
34 Immersion lithography has enabled microchip manufacturers to produce higher quality computer chips.
Questions 35-40
Complete the table below. Write NO MORE THAN THREE WORDS from the passage.
| Method | Light used | Wavelength | Material used to condense light |
|---|---|---|---|
| Lithography | Ultraviolet | 193 nm | air or (38)……………….. |
| Immersion lithography | (35)……………. | (36)……………. | (39)…………………… |
| X-ray lithography | X-rays | (37)………………… | (40)………………… |
