Heatwaves, drought and floods have hit the world over the past year, and experts said they will get worse if leaders fail to act.
But many countries are grappling with Ukraine's war and the surging prices of food and energy setting the stage for a two weeks of tough negotiations.
Here are four things to keep an eye on from November 6 to 18 at the Red Sea resort of Sharm-El-Sheikh.
Keeping 1.5°C alive
UN Secretary General António Guterres in October said the world faces a “catastrophe”.
His comments came as a UN report showed the world was set for warming of 2.8°C degrees by the end of the century.
This is far beyond the goal of the Paris deal signed at the 2015 Cop21 that aimed to limit warming to 1.5°C and keep it well below 2°C on pre-industrial levels.
“Global and national climate commitments are falling pitifully short,” Mr Guterres said.
Countries at Cop26 last year signed the Glasgow Climate Pact, which reaffirmed their commitment to the Paris deal. Talks at Cop27 will try to keep the 1.5°C goal alive.
“It was accepted in Glasgow that current pledges for 2030 are not in line with limiting warming,” said Bob Ward, policy and communications director at the Grantham Research Institute on Climate Change and the Environment at London School of Economics.
“Is 1.5°C still alive? It looks grim and difficult to imagine now. The most recent [UN] IPCC report in April suggested it would hit 1.5°C by mid-century.”
Loss and damage
Loss and damage, compensating developing countries for the consequences of climate change, is expected to become a critical and potentially divisive issue at Cop27.
Compensation has been resisted by wealthier countries — who also tend to be the worst emitters — as they fear it could leave them open to huge bills.
But the crisis in Pakistan this year has again brought loss and damage into sharp focus.
The country, responsible for one per cent of global emissions, suffered a series of climate disasters in 2022 that the UN has attributed to climate change. They culminated in floods that killed about 1,600 people, inundated large parts of the country and forced 33 million people towards destitution.
At Cop26, nations rejected proposals to establish such a fund but agreed to talk about it.
Egypt, along with China and the Group of 77 — a body of developing countries chaired by Pakistan — want it included as a topic for discussion on the Cop27 agenda that will be set at the start of the summit.
Impact of war in Ukraine
Russia’s invasion of Ukraine has inflamed global tensions and led to soaring energy and food bills.
This could make the talks even more fraught amid the challenging economic backdrop and tense ties between major powers.
However, the UN Special Rapporteur on Climate Change Ian Fry has said the conflict could be a “wake-up” call for countries to become self-sufficient in energy.
Speaking to UN news, he said countries could turn to renewables more quickly as they are the cheapest way to achieve self-sufficiency.
“We're seeing Portugal moving towards 100 per cent renewable. We know Denmark is also doing that, and I think that will drive other countries to see the need to be renewable and energy self-sufficient”, he said.
Tense ties between the US and China
Central to the progress of the talks are the relations between the US and China, as together both countries account for about half of global greenhouse gas emissions.
But China halted climate dialogue with the US in August after the House of Representatives Speaker Nancy Pelosi visited Taiwan.
This meant the China-US Climate Working Group announced in Glasgow has been paused.
US President Joe Biden said he will attend, but Chinese President Xi Jinping is not expected to travel.
However, Chinese climate negotiator Xie Zhenhua is expected to attend and questions are being asked if he and US climate envoy John Kerry will talk.
Separately, the two-day G20 summit hosted by Indonesia starts in Bali on November 15. Observers will be watching what happens there when the agenda of health, energy sustainability and digital transformation is discussed.