Several key international agreements and initiatives aim to mitigate climate change:

1. Paris Agreement (2015): Signed by nearly 200 countries, it sets targets to limit global warming to well below 2 degrees Celsius above pre-industrial levels, with efforts to limit it to 1.5 degrees Celsius. It emphasizes nationally determined contributions (NDCs) and regular reviews to strengthen commitments.

2. Kyoto Protocol (1997): The first international treaty committing developed countries to reduce greenhouse gas emissions. It introduced emissions reduction targets and mechanisms like emissions trading.

Challenges in implementing these agreements include:

1. Political Will: Some countries may lack political will or face internal opposition to commit to ambitious emission reduction targets.

2. Funding and Support: Developing countries often need financial and technological support to transition to low-carbon economies and adapt to climate impacts.

3. Monitoring and Compliance: Ensuring accurate reporting and verifying emissions reductions can be challenging, requiring robust monitoring systems and international cooperation.

4. Global Coordination: Differences in national priorities and economic disparities among countries can hinder effective global coordination and collective action.

Addressing these challenges requires continued diplomatic efforts, financial commitments, technological innovation, and enhanced international cooperation to achieve the goals set forth in these agreements and initiatives.