High level segment of COP21 talks begin
This is where the truly tough work begins as ministers begin negotiations on a draft climate agreement.
In the last week, over 40,000 delegates have been hammering out the technical details of a deal with a new draft text agreed on Saturday.
This week is all about brackets and eliminating them.
There are 939 groups of square brackets in the draft text, each representing an area of disagreement with a set of options ministers will have to decide between.
A deal is expected before the week is out, but it's all in the details; the choice to make it legally binding or just partly, or not at all.
The choice to try to limit global warming to two degrees, or well under two degrees, the choice to help poor countries deal with climate change, but in what ways and how much.
This is where the truly tough work begins.
The perceived success of these talks will rest on the balance between brave decisions and compromise and just how ambitious ministers will be.