Cop26 president Alok Sharma has warned that there is still a lot more to be done to secure agreement at the summit.
Here are some key questions about the process answered.
– Where are we up to?
There is a first draft text of the “cover decision” – the topline deal that could be secured in Glasgow which urges countries to increase their plans to cut emissions up to 2030 by next year, and double adaptation finance to help developing countries cope with the impact of the climate crisis.
There are also draft texts, published in the early hours of Thursday, on future climate finance for developing countries, on adaptation, addressing loss and damage that vulnerable countries are suffering from extreme weather.
And parts of the “Paris rulebook” for the way the global climate treaty will work – covering things like transparency about what countries are doing on climate change and how carbon trading markets will work – known as Article 6, have also got new drafts.
But they are all still being negotiated, with concerns particularly about progress on Article 6 and finance.
– How do the negotiations work?
Pairs of ministers from different countries have been tasked by the Cop26 president to meet delegations from country groupings such as the Africa group and the Least Developed Countries as well as individual countries, for discussions.
They feed back to the president and his negotiating team, who also speak to delegations in bilateral meetings, while different country delegations also talk to each other in corridors and rooms about the issues and what they want to see in the texts.
There are also meetings for all ministers, and delegations return periodically for plenary meetings of all countries to see where the negotiations are up to – and finally to approve agreements that have been secured.
– What happens next?
The first part of the closing plenary to adopt the decisions countries have already made in some areas is taking place on Thursday.
A new draft text of the cover decision and on a range of issues is expected overnight, drawing on feedback received by countries.
On Friday there is another meeting of ministers to consider the full set of draft decisions and in Mr Sharma’s words “resolve in a balanced manner what I hope will be the few remaining issues”.
– Is anything else happening?
The UK Cop presidency has been holding themed days throughout Cop26 to focus on “real world actions” being taken by countries and businesses in areas from curbing deforestation to boosting green technology.
But those have ended with the focus on cities, states and regions on Thursday.
There are likely to be protests in and around the summit in the final hours.
Elsewhere, barring any more surprise announcements such as the US and China joint declaration that they will take more action on emissions in the 2020s, the focus is on the negotiations until the gavel comes down.
– And will it finish on time?
That remains to be seen.
But it is worth bearing in mind than no Cop in the past decade has finished on time. The record is Cop25 in Madrid in 2019, which finished on the Sunday.