CFC is mainly responsible for:

Question

Accepted Answer

Chlorofluorocarbons (CFCs) are primarily responsible for ozone depletion, which is why Option 1 is the correct answer. CFCs are compounds that were commonly used in refrigeration, air conditioning, foam blowing, and aerosol propellants. When CFCs are released into the atmosphere, they eventually reach the stratosphere, where they are broken down by ultraviolet (UV) radiation from the sun. This breakdown releases chlorine atoms, which are highly reactive and can destroy ozone molecules. A single chlorine atom can destroy thousands of ozone molecules, leading to significant thinning of the ozone layer, commonly referred to as the "ozone hole."

The ozone layer is crucial because it absorbs the majority of the sun's harmful ultraviolet radiation, protecting living organisms on Earth from its damaging effects, such as skin cancer and cataracts in humans, as well as negative impacts on wildlife and ecosystems.

Now, let's explain why the other options are incorrect:

2. Greenhouse effect: The greenhouse effect is primarily caused by gases such as carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), which trap heat in the Earth's atmosphere. While CFCs are also greenhouse gases, their primary environmental impact is on ozone depletion, not the greenhouse effect.

3. Acid rain: Acid rain is caused by the release of sulfur dioxide (SO2) and nitrogen oxides (NOx) into the atmosphere, which then react with water vapor to form sulfuric and nitric acids. CFCs do not contribute to acid rain formation.

4. Smog: Smog is a type of air pollution that results from the reaction of sunlight with pollutants such as volatile organic compounds (VOCs) and nitrogen oxides (NOx). CFCs are not involved in the formation of smog.

In conclusion, while CFCs have some impact on the greenhouse effect, their most significant and well-documented environmental impact is on ozone depletion, making Option 1 the correct answer.