The Ozone Hole Reading Answers

Sep 28, 2022

The Ozone Hole Reading Answers 14 questions that have to be answered in 20 minutes. The Ozone Hole Reading Answers comprises question types, namely-write the appropriate number, write the appropriate letter and answer the questions about the diagram. For writing the appropriate number, choose from options i-ix.Write the appropriate letter from A-H and write the appropriate letter from A-E Candidates are required to answer based on a given cue. They are required to choose from multiple options. Candidates must read the IELTS reading passage, identify keywords, and recognize synonyms to answer the question.

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Reading Passage Question

Paragraph A

Ozone is a bluish gas that is harmful to breathe. Nearly 90% of the Earth's ozone is in the stratosphere and is referred to as the ozone layer. Ozone absorbs a band of ultraviolet radiation called UVB that is particularly harmful to living organisms. Stratospheric ozone is constantly being created and destroyed through natural cycles. Various ozone-depleting substances, however, accelerate the destruction processes, resulting in lower than normal ozone levels. Reductions in ozone levels will lead to higher levels of UVB reaching the Earth's surface. The sun's output of UVB does not change; rather, less ozone means less protection, and hence more UVB reaches the Earth. Studies have shown that in the Antarctic, the amount of UVB measured at the surface can double during the annual ozone hole. Laboratory and epidemiological studies demonstrate that UVB causes non-melanoma skin cancer and plays a major role in malignant melanoma development. In addition, UVB has been linked to cataracts.

Paragraph B

Dramatic loss of ozone in the lower stratosphere over Antarctica was first noticed in the 1970s by a research group from the British Antarctic Survey (BAS) who were monitoring the atmosphere above Antarctica from a research station. Folklore has it that when the first measurements were taken in 1975, the drop in ozone levels in the stratosphere was so dramatic that at first, the scientists thought their instruments were faulty. Replacement instruments were built and flown out and it wasn't until they confirmed the earlier measurements, several months later, that the ozone depletion observed was accepted as genuine. Another story goes that the BAS satellite data didn't show the dramatic loss of ozone because the software processing the raw ozone data from the satellite was programmed to treat very low values of ozone as bad readings. Later analysis of the raw data when the results from the British Antarctic Survey team were published, confirmed their results and showed that the loss was rapid and large-scale; over most of the Antarctica continent.

Paragraph C

Ozone occurs naturally in the atmosphere. The earth's atmosphere is composed of several layers. We live in the Troposphere, ground level up to about 10km high, where most of the weather occurs such as rain, snow, and clouds. Above that is the Stratosphere, an important region in which effects such as the Ozone Hole and Global Warming originate. The layer next to space is the Exosphere and then going inwards there are the Thermosphere and the Mesosphere. Supersonic passenger jets fly just above the troposphere whereas subsonic commercial airliners are usually well in the troposphere. The narrow region between these two parts of the atmosphere is called the Tropopause. Ozone forms a layer in the stratosphere, thinnest in the tropics and denser towards the poles. The amount of ozone above a point on the earth's surface is measured in Dobson units (DU) - typically ~260 DU near the tropics and higher elsewhere, though there are large seasonal fluctuations. It is created when ultraviolet radiation in the form of sunlight strikes the stratosphere, splitting oxygen molecules into atomic oxygen. The atomic oxygen quickly combines with further oxygen molecules to form ozone.

Paragraph D

The Ozone Hole often gets confused in the popular press and by the general public with the problem of global warming. Whilst there is a connection because ozone contributes to the greenhouse effect, the Ozone Hole is a separate issue. Over Antarctica (and recently over the Arctic), stratospheric ozone has been depleted over the last 15 years at certain times of the year. This is mainly due to the release of man-made chemicals containing chlorine such as CFCs (ChloroFluorocarbons) but also compounds containing bromine, other related halogen compounds, and also nitrogen oxides. CFCs are a common industrial product, used in refrigeration systems, air conditioners, aerosols, solvents, and in the production of some types of packaging. Nitrogen oxides are a by-product of combustion processes, for example, aircraft emissions.

Paragraph E

The ozone depletion process begins when CFCs and other ozone-depleting substances are emitted into the atmosphere where winds efficiently mix and evenly distribute the gases. CFCs are extremely stable, and they do not dissolve in rain. After several years, natural gases in the stratosphere combine with CFCs and this releases chlorine atoms, halons, and methyl bromide. These in turn all release bromine atoms and it is these atoms that destroy ozone. It is estimated that one chlorine atom can destroy over 100,000 ozone molecules before it is removed from the stratosphere.

Paragraph F

The first global agreement to restrict CFCs came with the signing of the Montreal Protocol in 1987 ultimately aiming to reduce them by half by the year 2000. Two revisions of this agreement have been made in the light of advances in scientific understanding, the latest being in 1992. An agreement has been reached on the control of industrial production of many halocarbons until the year 2030. The main CFCs will not be produced by any of the signatories after the end of 1995, except for a limited amount for essential uses, such as medical sprays. The countries of the European Community have adopted even stricter measures. Recognizing their responsibility to the global environment they have agreed to halt production of the main CFCs from the beginning of 1995. It was anticipated that these limitations would lead to a recovery of the ozone layer within 50 years of 2000. The World Meteorological Organisation estimated 2045 but recent investigations suggest the problem is perhaps on a much larger scale than anticipated.

Solution with Explanation
Questions 14 – 19:
The reading passage on The Ozone Hole has 6 paragraphs (A – F).
From the list of headings below (i – ix) choose the most suitable headings for paragraphs A – F.
Write the appropriate number (i – ix) in boxes 14 – 19 on your answer sheet.

The Destruction Process How Is Ozone Formed? How Technology Can Help Artificial Emissions What Is Being Done? The Function of the Ozone Layer Empirical Analysis Initial Identification Hospitalisation

Paragraph A

Answer: vi
Supporting Sentence: Ozone absorbs a band of ultraviolet radiation called UVB that is particularly harmful to living organisms. Stratospheric ozone is constantly being created and destroyed through natural cycles. Various ozone-depleting substances, however, accelerate the destruction processes, resulting in lower than normal ozone levels. Reductions in ozone levels will lead to higher levels of UVB reaching the Earth’s surface.
Keywords: Ozone layer, reduction, ultraviolet radiation
Keywords Location: Paragraph A, first few lines
Explanation: The Ozone hole is briefly explained in paragraph A. A bluish gas that is dangerous to breathe in is ozone. The ozone layer, which contains about 90% of the Earth's ozone, is located in the stratosphere. UVB, a particular damaging wavelength of ultraviolet radiation for living things, is absorbed by ozone. Natural processes continuously generate and deplete stratospheric ozone. However, a number of ozone-depleting compounds speed up the ozone's depletion processes, leaving levels below average. Ozone depletion will increase the amount of UVB that reaches the Earth's surface. These lines indicate that the text describes the Ozone Hole and the role of the Ozone Layer.

Paragraph B

Answer: viii
Supporting Sentence: “Dramatic loss of ozone in the lower stratosphere over Antarctica was first noticed in the 1970s by a research group from the British Antarctic Survey (BAS) who were monitoring the atmosphere above Antarctica from a research station. Folklore has it that when the first measurements were taken in 1975, the drop in ozone levels in the stratosphere was so dramatic that at first, the scientists thought their instruments were faulty. Replacement instruments were built and flown out and it wasn’t until they confirmed the earlier measurements, several months later, that the ozone depletion observed was accepted as genuine.”
Keywords: dramatic loss, atmosphere, Antarctica, ozone
Keywords Location: Paragraph B, first few lines
Explanation: The ozone layer's first identification is explained in paragraph B. In the 1970s, a research team from the British Antarctic Survey (BAS) was keeping an eye on the atmosphere above Antarctica from a research station when they first discovered a dramatic depletion of ozone in the lower stratosphere. According to mythology, the reduction in stratospheric ozone levels during the initial observations in 1975 was so abrupt that the scientists initially believed their equipment was broken. The ozone depletion seen wasn't recognised as real until replacement instruments were made and flew out and validated the earlier measurements, several months later.

Paragraph C

Answer: ii
Supporting Sentence: Ozone forms a layer in the stratosphere, thinnest in the tropics, and denser towards the poles. The amount of ozone above a point on the earth’s surface is measured in Dobson units (DU) – typically ~260 DU near the tropics and higher elsewhere, though there are large seasonal fluctuations. It is created when ultraviolet radiation in the form of sunlight strikes the stratosphere, splitting oxygen molecules into atomic oxygen. The atomic oxygen quickly combines with further oxygen molecules to form ozone.
Keywords: ozone, forms, layer, earth’s surface
Keywords Location: Paragraph C, line 8
Explanation: In paragraph C, it is described how the ozone layer exists naturally in the atmosphere, which is made up of numerous layers. According to the ninth line, ozone creates a layer in the stratosphere that is denser in the poles and thinner in the tropics. Dobson units (DU), a metric used to measure the quantity of ozone over a certain location on the earth's surface, are normally around 260 DU near the tropics and higher elsewhere, though there are significant seasonal variations. When sunlight's UV rays hit the stratosphere and divide oxygen molecules into atomic oxygen, it is produced. To create ozone, more oxygen molecules swiftly join the atomic oxygen. These lines show the formation of ozone.

Paragraph D

Answer: iv
Supporting Sentence: Antarctica (and recently over the Arctic), stratospheric ozone has been depleted over the last 15 years at certain times of the year. This is mainly due to the release of man-made chemicals containing chlorine such as CFCs (ChloroFluoroCarbons) but also compounds containing bromine, other related halogen compounds, and also nitrogen oxides. CFCs are a common industrial product, used in refrigeration systems, air conditioners, aerosols, solvents, and in the production of some types of packaging. Nitrogen oxides are a by-product of combustion processes, for example, aircraft emissions.
Keywords: man-made, chemicals, industrial product, by-product
Keywords Location: Paragraph D, line 3
Explanation: Line 3 of paragraph D states that over Antarctica (and more recently over the Arctic) stratospheric ozone levels have decreased during the past 15 years at specific periods of the year. This is primarily due to the discharge of man-made chemicals containing chlorine, such as CFCs (ChloroFluoroCarbons), but also compounds containing bromine, other related halogen compounds, and nitrogen oxides. CFCs are a widely used industrial product that are used in air conditioners, aerosol cans, solvents, and various types of packaging. As an example of a combustion process byproduct, consider the emissions from aircraft. These lines explain how man-made emissions contribute to ozone depletion.

Paragraph E

Answer: i
Supporting Sentence: The ozone depletion process begins when CFCs and other ozone-depleting substances are emitted into the atmosphere where winds efficiently mix and evenly distribute the gases.
Keywords: depletion, emitted, atmosphere, mix, distribute, gases
Keywords Location: Paragraph E
Explanation: The ozone depletion process is described in paragraph E. The ozone depletion process is said to begin with the emission of CFCs and other ozone-depleting compounds into the atmosphere, where winds effectively mix and disseminate the gases. Since they are so stable, CFCs do not break down in rain. After a number of years, natural gases in the stratosphere react with CFCs, releasing methyl bromide, halons, and chlorine atoms as a result. All of these, in turn, produce bromine atoms, and it is these atoms that cause ozone to be destroyed. It is clear from these lines that paragraph E outlines how ozone is destroyed.

Paragraph F

Answer: v
Supporting Sentence: The global environment has agreed to halt production of the main CFCs from the beginning of 1995. It was anticipated that these limitations would lead to a recovery of the ozone layer within 50 years of 2000. The World Meteorological Organisation estimated 2045 but recent investigations suggest the problem is perhaps on a much larger scale than anticipated.
Keywords: halt production, investigations, limitations, recovery, ozone layer
Keywords Location: Paragraph F, last line
Explanation: The first accord limiting CFCs is discussed in paragraph F. In recognition of their obligation to protect the environment, it is said that the major CFCs will no longer be produced starting in 1995. The ozone layer was expected to recover within 50 years of the year 2000 as a result of these restrictions. The World Meteorological Organisation predicted the problem would exist until 2045, but recent research indicates it may exist on a far greater scale. It is clear from the paragraph's final line that it discusses what is being done.

Questions 20 – 25:
Complete the following statements (questions 20 – 25) with the best ending from the box below (A – H) according to the information in the reading passage The Ozone Hole.
Write the appropriate letter (A – H) on your answer sheet.
There are more sentence endings (A – H) than questions so you will not need to use them all.

the location of the layer relative to the earth. the discharge of synthetic chemicals into the atmosphere. the satellite orbiting the earth. the normal components of the earth’s atmosphere. the anomalous readings taken earlier. the issue of the heating up of the earth’s atmosphere. recent investigations into the strength of Dobson Units. the cessation of the release of most CFC gases into the atmosphere

International agreements will eventually lead to…

Answer: H
Supporting Sentence: The first global agreement to restrict CFCs came with the signing of the Montreal Protocol in 1987 ultimately aiming to reduce them by half by the year 2000. Two revisions of this agreement have been made in the light of advances in scientific understanding, the latest being in 1992.
Keywords: global agreement, scientific understanding, CFCs
Keywords Location: Paragraph F, initial lines
Explanation: The first few lines of paragraph F mention that the Montreal Protocol, which was signed in 1987 and has as its ultimate goal the reduction of CFCs by half by the year 2000, was the first global agreement to control CFCs. This agreement has undergone two amendments, the most recent in 1992, in light of new scientific knowledge. These lines indicate that international agreements were made to limit the atmospheric discharge of CFCs. Therefore, it is clear that the worldwide accords will eventually result in the end of the atmospheric release of the majority of CFC chemicals.

An apocryphal BAS story cites that equipment was changed to measure…

Answer: E
Supporting Sentence: When the first measurements were taken in 1975, the drop in ozone levels in the stratosphere was so dramatic that at first, the scientists thought their instruments were faulty. Replacement instruments were built and flown out and it wasn’t until they confirmed the earlier measurements, several months later.
Keywords: measurement, stratosphere, earlier, replacement
Keywords Location: Paragraph B
Explanation: In paragraph B, it is mentioned that the British Antarctic Survey (BAS) was keeping an eye on the atmosphere above Antarctica from a research station. According to mythology, the reduction in stratospheric ozone levels during the initial observations in 1975 was so abrupt that the scientists initially believed their equipment was broken. The ozone depletion reported was first acknowledged as real once replacement sensors were manufactured and flown out, although it took many months for them to confirm the earlier data.These lines imply that the initial measurements didn't produce the anticipated results, causing the scientists to think that the equipment was broken. But once the replacement instruments were created, they were able to validate the earlier measurements. It follows that it is undisputed that a BAS fable claims that equipment was modified in order to measure the previous aberrant data.

It is a common mistake to associate the Ozone Hole problem with…

Answer: F
Supporting Sentence: The Stratosphere, an important region in which effects such as the Ozone Hole and Global Warming originate.
Keywords: stratosphere, ozone hole, global warming
Keywords Location: Paragraph C, line 4
Explanation: According to paragraph C, ozone exists naturally in the atmosphere, which is made up of various layers. The Stratosphere, a significant region where phenomena like the Ozone Hole and global warming arise, is referenced in the fourth line. According to these lines, it is a typical blunder to mix up the ozone hole issue with the problem of the earth's atmosphere heating up.

The thickness of the Ozone layer varies with…

Answer: A
Supporting Sentence: Ozone forms a layer in the stratosphere, thinnest in the tropics, and denser towards the poles.
Keywords: Ozone, stratosphere, tropics, poles
Keywords Location: Paragraph C, line 9
Explanation: According to the 9th line of paragraph C, ozone produces a layer in the stratosphere that is denser in the poles and thinner in the tropics. These lines show that the ozone layer's thickness fluctuates depending on where it is in relation to the Earth.

The Ozone layer is destroyed by a by-product of CFCs reacting with…

Answer: D
Supporting Sentence: The ozone depletion process begins when CFCs and other ozone-depleting substances are emitted into the atmosphere where winds efficiently mix and evenly distribute the gases.
Keywords: depletion, emitted, atmosphere, gases, CFCs
Keywords Location: Paragraph E, first line
Explanation: In paragraph E, where it is stated that the ozone depletion process begins with the emission of CFCs and other ozone-depleting compounds into the atmosphere, where winds effectively mix and disseminate the gases, we see a reference to CFC. These lines show that ozone depletion begins when CFC and other ozone-depleting compounds are released into the atmosphere, where winds mix and disperse them. It is evident that the ozone layer is damaged as a result of CFCs reacting with the regular elements of the Earth's atmosphere.

Common household appliances contribute to…

Answer: B
Supporting Sentence: CFCs are a common industrial product, used in refrigeration systems, air conditioners, aerosols, solvents, and in the production of some types of packaging.
Keywords: CFCs, industrial, refrigeration system, air conditioners, aerosols
Keywords Location: Paragraph D, line 3
Explanation: According to the third sentence of paragraph D, over Antarctica (and more lately over the Arctic) at specific periods of the year for the past 15 years, stratospheric ozone has been reduced. The discharge of man-made chemicals containing chlorine, such as CFCs (ChloroFluoroCarbons), as well as compounds containing bromine, other closely related halogen compounds, and nitrogen oxides is mostly to blame for this. CFCs are a widely used industrial product that are used in air conditioners, aerosol cans, solvents, and various types of packaging. According to these lines, everyday household items help to discharge synthetic chemicals into the atmosphere.

Questions 26 and 27:
Answer questions 26 and 27 below regarding the diagram of the earth and its layers of the atmosphere at the bottom of the page.
Write the appropriate letter (A – E) on your answer sheet.

In which atmosphere layer would you find the Ozone layer and hole?

Answer: D
Supporting Sentence: The earth’s atmosphere is composed of several layers. We live in the Troposphere, ground level up to about 10km high, where most of the weather occurs such as rain, snow, and clouds. Above that is the Stratosphere, an important region in which effects such as the Ozone Hole and Global Warming originate.
Keywords: troposphere, stratosphere, ozone hole, global warming
Keywords Location: Paragraph C, first few lines
Explanation: The first lines of paragraph C state that ozone exists naturally in the atmosphere. There are multiple levels to the earth's atmosphere. The majority of weather, including rain, snow, and clouds, happens in the troposphere, which is up to about 10 km above ground where humans live. A significant location where effects like the Ozone Hole and global warming arise is the stratosphere, which is located above that. These lines show where the ozone layer and hole will be located: in layer D, 40 kilometres above sea level.

In which atmosphere layer would you find a conventional passenger airliner usually flying?

Answer: E
Supporting Sentence: The supersonic passenger jets fly just above the troposphere whereas subsonic commercial airliners are usually well in the troposphere. The narrow region between these two parts of the atmosphere is called the Tropopause.
Keywords: supersonic, airliners, narrow region, atmosphere
Keywords Location: Paragraph C, line 6^th
Explanation: In paragraph C, when it is stated that supersonic passenger jets fly just above the troposphere while subsonic commercial airliners are often well in the troposphere, we have a reference for how a conventional passenger airliner typically flies. Tropopause refers to the constrictive space between these two atmospheric regions. The normal passenger aircraft (supersonic passenger jets fly) is located just above the troposphere, as shown by the highlighted lines and the earth's figure.