This year's climate summit comes amid spiralling energy costs and diplomatic tensions.
However, choosing Egypt as the venue has attracted controversy.
Some human rights and climate campaigners say the government has stopped them attending because they have criticised its rights record.Ahead of the meeting, countries were asked to submit ambitious national climate plans. Only 25 have - so far.Helping countries to prepare and deal with climate changeSome areas not fully resolved or covered at COP26 will be picked up:
Loss and damage finance - money to help countries recover from the effects of climate change, rather than just prepare for it Establishment of a global carbon market - to price the effects of emissions into products and services globallyfor focused talks and announcements on issues including gender, agriculture and biodiversity.In 2009, developed countries committed to give $100 billion a year, by 2020, to developing countries to help them reduce emissions and prepare for climate change.But developing nations are also calling for payments for "loss and damage" - the impacts faced now.