What about money?
Money has been a sticking point throughout the negotiations.
Developing countries say they need financial and technological help to leapfrog fossil fuels and move straight to renewables.
Currently they have been promised US $100bn (£67bn) a year by 2020 - not as much as many countries would like.
The agreement requires rich nations to maintain a $100bn a year funding pledge beyond 2020, and to use that figure as a "floor" for further support agreed by 2025.
The deal says wealthy countries should continue to provide financial support for poor nations to cope with climate change and encourages other countries to join in on a voluntary basis.
Dr Ilan Kelman of UCL, London, says the lack of time scales is "worrying".
"The starting point of $100bn per year is helpful, but remains under 8% of worldwide declared military spending each year."