Answer: An international treaty (1987) to phase out substances that deplete the ozone layer, primarily CFCs.
- A An international agreement specifically aimed at reducing global CO<sub>2</sub> emissions from industry
- B An international treaty (1987) to phase out substances that deplete the ozone layer, primarily CFCs
- C A multilateral treaty establishing protected reserves specifically for global biodiversity conservation
- D A national pollution control law that specifically governs river and stream water quality
Correct answer: B. An international treaty (1987) to phase out substances that deplete the ozone layer, primarily CFCs
Explanation: The Montreal Protocol (1987) is an international treaty signed by 197 nations to phase out ozone-depleting substances (CFCs, HCFCs, halons, methyl bromide). It is considered the most successful environmental treaty; the ozone hole is slowly recovering as a result.
Sunlight passes through the atmosphere and warms the surface; the surface re-radiates this energy as infrared heat, which greenhouse gases (CO₂, CH₄, water vapour) absorb and trap - a naturally beneficial process that intensifies into global warming as gas concentrations rise from human activity.
Concept context
Pollution, global warming, ozone depletion, deforestation, and sustainability. Important for NEET and general awareness.