The question asks which international treaty aims to address climate change by keeping global warming below 2°C above pre-industrial levels. Let's analyze each option to determine the correct answer:
- Montreal Protocol: This treaty focuses on protecting the ozone layer by phasing out the production of numerous substances responsible for ozone depletion, not specifically aimed at climate change limits.
- Paris Agreement: An international treaty under the United Nations Framework Convention on Climate Change (UNFCCC), it addresses climate change with a crucial goal: limiting global warming to well below 2°C above pre-industrial levels, aiming for 1.5°C if possible.
- Kyoto Protocol: This is another climate treaty, but it primarily commits countries to reduce greenhouse gas emissions with different targets for various nations, rather than setting a specific temperature goal.
- Copenhagen Accord: While it acknowledges the scientific view that the increase in global temperature should be below 2°C, it lacks the binding legal force that the Paris Agreement encompasses.
Based on the goal of limiting temperature increases to below 2°C, the Paris Agreement is the correct choice. It specifically stipulates this aim and constitutes legally binding commitments to tackle climate change.