Understanding Ozone-Depleting Substances Control

The question asks to identify the specific international agreement established to regulate and reduce the emission of substances harmful to the ozone layer. Ozone-depleting substances (ODS) are chemicals that deplete the Earth's protective stratospheric ozone layer. Controlling their emissions is crucial for environmental protection.

Analyzing International Environmental Agreements

Let's examine the options provided:

• Basel Convention: This international treaty, adopted in 1989, controls the transboundary movements of hazardous wastes and their disposal. It is primarily concerned with waste management, not specifically ozone-depleting substances.
• Montreal Protocol: Signed in 1987, the Montreal Protocol on Substances that Deplete the Ozone Layer is a landmark international agreement designed specifically to protect the ozone layer by phasing out the production and consumption of numerous substances responsible for ozone depletion. These include chlorofluorocarbons (CFCs), halons, and other chemicals.
• Earth Summit: Held in Rio de Janeiro in 1992 (also known as the Rio Summit or UN Conference on Environment and Development), this was a major United Nations conference addressing broad environmental issues, including climate change, biodiversity, and sustainable development. While important, it wasn't the specific agreement for ODS control.
• Kyoto Protocol: This protocol, adopted in 1997, is an international treaty that extends the 1992 United Nations Framework Convention on Climate Change (UNFCCC) with commitments in legally binding overachieving targets. It focuses on reducing greenhouse gas emissions to combat climate change, not ozone-depleting substances.

Montreal Protocol: The Key Agreement

The Montreal Protocol is directly and specifically aimed at the control of emissions of ozone-depleting substances. It has been remarkably successful in reducing the global production and consumption of these harmful chemicals, leading to the slow recovery of the ozone layer.

Key Features of the Montreal Protocol:

• Objective: To phase out the production and consumption of Ozone Depleting Substances (ODS).
• Scope: Covers a wide range of ODS, including CFCs, halons, carbon tetrachloride, and methyl chloroform.
• Mechanism: Established binding progressive phase-out schedules for developed and developing countries.
• Success: Widely regarded as one of the most effective international environmental treaties.

Therefore, the Montreal Protocol is the correct answer as the international agreement signed to control emissions of ozone-depleting substances.