Comprehension : Comprehension

Q 459 / 466

UPSC CSE Prelims 2011

Read the following passage and answer the items that follow. Your answers to these items should be based on the passage only.
Ecosystems provide people with a variety of goods and services; food, clean water, clean air, flood control, soil stabilization, pollination, climate regulation, spiritual fulfilment and aesthetic enjoyment, to name just a few. Most of these benefits either are irreplaceable or the technology necessary to replace them is prohibitively expensive. For example, potable fresh water can be provided by desalinating sea-water, but only great cost. The rapidly expanding human population has greatly modified the Earth’s ecosystems to meet their increased requirements of some of the goods and services, particularly food, fresh water, timber, fiber and fuel. These modifications have contributed substantially to human well
being and economic development. The benefits have not been equally distributed. Some people have actually been harmed by these changes. Moreover, short-term increases in some ecosystem goods and services have come at the cost of the long-term degradation of others. For example, efforts to increase the production of food and fibre have decreased the ability of some ecosystems to provide clean water, regulate flooding and support biodiversity.

With reference to the passage, consider the following statements.
Expanding human’ population has an adverse effect on:

  1. Spiritual fulfillment
  2. Aesthetic enjoyment
  3. Potable fresh water
  4. Production of food and fibre
  5. Biodiversity.

Which of the statements given above are correct?

EXPLANATION

Correct Option (c)

Statements 3 and 5 are correct.

  • Statement 3 (Potable fresh water): The passage explicitly states that "efforts to increase the production of food and fibre have decreased the ability of some ecosystems to provide clean water". This directly indicates an adverse effect on the availability of potable fresh water due to human activities driven by population expansion.
  • Statement 5 (Biodiversity): The passage notes that "efforts to increase the production of food and fibre have decreased the ability of some ecosystems to provide clean water, regulate flooding and support biodiversity". This highlights an adverse impact on biodiversity as a consequence of ecosystem modifications.

Incorrect Options:

  • Statement 1 (Spiritual fulfilment): The passage lists spiritual fulfilment as an ecosystem service but does not provide any information or evidence to suggest that expanding human population has an adverse effect on it.
  • Statement 2 (Aesthetic enjoyment): Similar to spiritual fulfilment, aesthetic enjoyment is mentioned as an ecosystem service, but the passage does not indicate any adverse impact on it resulting from the expanding human population.
  • Statement 4 (Production of food and fibre): The passage states that the rapidly expanding human population has "greatly modified the Earth’s ecosystems to meet their increased requirements of some of the goods and services, particularly food, fresh water, timber, fiber and fuel". It also refers to "efforts to increase the production of food and fibre". This indicates an increase in the production of food and fibre, rather than an adverse effect.