The 2015 Paris Agreement, also known as the COP 21, is a historic international agreement on climate change, signed by 196 countries in December 2015. The agreement aims to limit global warming to well below 2 degrees Celsius above pre-industrial levels, with a goal to limit the temperature increase to 1.5 degrees Celsius.

The Paris Agreement is the culmination of decades of international efforts to address climate change and marks a major turning point in global efforts to combat rising temperatures, extreme weather events, sea level rise, and other climate-related impacts.

The agreement outlines several key objectives, including:

1. Mitigation: Countries agree to reduce their greenhouse gas emissions to limit global warming by reducing the use of fossil fuels and shifting towards renewable energy sources.

2. Adaptation: Countries also agree to adapt to the impacts of climate change such as rising sea levels, droughts, and extreme weather events.

3. Financing: Developed countries will provide $100 billion per year to help developing countries transition to renewable energy and adapt to the impacts of climate change.

4. Transparency and accountability: Countries agree to regularly report their progress towards their climate targets, and a mechanism is established to assess whether they are meeting their commitments.

The Paris Agreement has been hailed as a historic achievement, demonstrating a collective commitment to address the impacts of climate change. However, there are still concerns that the targets outlined in the agreement may not be enough to limit global warming to below 2 degrees Celsius.

Moreover, in 2017, the United States announced its intention to withdraw from the agreement, a move that was met with widespread criticism and concern. However, the United States officially rejoined the agreement under President Joe Biden in February 2021.

Overall, the Paris Agreement represents an important step forward in the global effort to address climate change, but continued action and collaboration will be needed to ensure that the targets outlined in the agreement are achieved and that the world can avoid the worst impacts of climate change.