Question

The most serious ecological problem facing the world today is
(a) The greenhouse effect
(b)Human population growth
(c) The ozone problem
(d) Limited resources to feed, cloth, and house individuals
(e) The amount of garbage created daily

Answer 1

Hint: The most serious of environmental problems facing the world today is overpopulation.

Complete answer: Overpopulation is basically the condition where the population exceeds its sustainable size within a particular environment or habitat.

Overpopulation results from various factors such as increased natality, decreased mortality rates, the immigration to a new ecological niche, or even due to the sudden decline in available resources.
Human population growth is reaching unsustainable levels rapidly since it is facing a shortage of basic resources like water, food and fuel.
Additionally, the population rise in the less developed as well as the developing countries is further straining the already scarce resources.

Additional information: There are major problems associated with overpopulation: Inadequate fresh water for drinking as well as sewage treatment and effluent discharge. Increased levels of pollution, deforestation, and loss of ecosystems, changes in atmospheric composition and consequent global warming, etc.
As a whole, overpopulation results in totally disrupting the ecological arrangements as the resources are getting depleted. This disruption can further lead to the decline of other populations which compete for the same resources due to competition.

So, the correct answer is ‘ Human population growth’.

Note: One of the most common reasons for overpopulation is the introduction of foreign species to a relatively new ecological niche for which they have no natural predators previously present in that particular area.