Temperature and long-term goal
The deal calls for nations to work toward capping global temperature increases since pre-industrial times to 2 degrees Celsius (3.6 degrees Fahrenheit). The text acknowledges the need to strive for 1.5 degrees, a key demand of the countries most vulnerable to warming, including island states imperiled by rising seas. Nations will reduce emissions as soon as possible to “achieve a balance between anthropogenic emissions by sources and removals by sinks” like forests that absorb greenhouse gases.

Revision and reduction
To encourage more ambitious efforts, countries will need to update their current pollution-reduction pledges by 2020 and then do so every five years. That’s because plans submitted so far by 186 nations would guarantee a temperature cap of 2.7 degrees at best. Nations will periodically analyze collective progress toward achieving the goal of the Paris agreement. The first assessment, or “global stocktake,” will take place in 2023.

Sustainable development
The agreement establishes a “mechanism to contribute to the mitigation of greenhouse gas emissions and support sustainable development” and paves the way for voluntary cooperation between countries in meeting their pollution goals. Detailed rules for the market mechanism will be established at a later date.

Transparency
Governments agreed to set up a framework for monitoring, measuring and verifying emissions reductions. This will promote transparency on who is doing what and give those seeking to bring pressure on underperformers information to fuel their arguments. Developing countries were given some flexibility on different provisions, including on the scope, frequency and level of detail of reporting. Small island states and the least developed countries have lower requirements.

Paying for the deal
The deal obliges developed nations to help developing countries pay for reducing pollution and adapting to the impacts of climate change. Negotiators agreed to establish by 2025 a new target to scale up climate finance. The next goal will be to increase the $100 billion a year that they had previously agreed to provide by 2020. The text says developing nations in a position to do so “are encouraged to provide or continue to provide such support voluntarily.”

http://unfccc.int/resource/docs/2015/cop21/eng/l09r01.pdf