The percentage of contribution of CFCs in total global warming is?

KPSC Staff Nurse - 2016

Non Nursing Subjects

Easy

Appeared in: KPSC Staff Nurse - 2016

Explanation

Chlorofluorocarbons (CFCs) are recognized as significant greenhouse gases, contributing approximately 14% to the total effect of global warming.
While their most famous environmental impact is the depletion of the stratospheric ozone layer, CFCs are also very effective at trapping heat in the atmosphere.
The primary sources of CFCs have been industrial and consumer applications such as refrigerators, air-conditioners, and aerosol sprays.
Although their use has been drastically reduced by international treaties, their long atmospheric lifetime means they continue to contribute to warming.

Option A: This percentage is too low for CFCs. A 6% contribution is more accurately associated with Nitrous Oxide (N₂O), another potent greenhouse gas primarily from agricultural and industrial activities.
Option C: This is the largest percentage listed and represents the contribution of Carbon Dioxide (CO₂), which is the primary driver of global warming, mainly from the burning of fossil fuels.
Option D: This percentage represents the contribution of Methane (CH₄), the second most significant greenhouse gas, which is emitted from sources like agriculture (livestock), natural gas systems, and landfills.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Contribution of CFCs to Global Warming as background academic context rather than a clinical decision trigger.
Nurses play a vital role in public health by educating communities about the health risks associated with climate change, such as increased incidence of heat stroke, respiratory diseases from poor air quality, and the changing epidemiology of vector-borne diseases.
Community health nurses can advocate for and teach about environmentally safe practices, such as the proper disposal of old refrigerators and air conditioners to prevent the release of CFCs.
What if the question asked for the gas with the highest contribution to global warming? In that case, the correct answer would be Carbon Dioxide (CO₂), which accounts for about 60% of the effect.

How to Approach the Question

This is a factual recall question from environmental science.
First, identify the key components of the question: the specific substance (CFCs) and the effect being measured (percentage contribution to global warming).
Recall the relative contributions of the main greenhouse gases: Carbon Dioxide (CO₂) is the highest, followed by Methane (CH₄), then CFCs, and then Nitrous Oxide (N₂O).
Match the known approximate percentage for CFCs (around 14%) to the options provided.
Eliminate the other options by associating them with the other major greenhouse gases (60% for CO₂, 20% for CH₄, 6% for N₂O).

Concept Tested & Keywords

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