You should spend about 20 minutes on this task.

The graphs below show the size of the ozone hole over Antarctica and the production of three ozone-damaging gases from 1980 to 2000. Summarise the information by selecting and reporting the main features, and make comparisons where relevant.

Write at least 150 words.

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Model Answer

The given line graphs illustrate the changes in the Ozone hole size over the Antarctica region and the amount of three gases produced which caused damage to the ozone layer from 1980 to 2000.

The ozone hole was at its smallest size of about 400 thousand square kilometres in 1980, but 20 years later, it grew drastically to 3.6 million square kilometres. It increased by nine times. The only period when there was a reduction in the size was in the early 1990s (from 2 to 1.2 million square km).

In 1980, about 70 million tonnes of CFC–11 was produced, which remained stable for 3 years before undergoing a steady decline to below 10 million tonnes in the late 1990s. The production of CFC–12, on the other hand, showed an upward trend throughout the 20-year period from 25 to 50 million tonnes, surpassing the production of CFC–11 in 1989. N2O, however, was not produced until 1990, but its production grew rapidly to about 40 million tonnes by the year 2000.

Overall, the two graphs indicate that it was mainly CFC–12 and N2O, which gave rise to the expansion of ozone hole over Antarctica in the last two decades of the 20th century.