In just over four weeks, the annual United Nations climate talks will begin in Egypt.
COP27 is the successor to last year’s COP26 climate talks in Glasgow, but the energy crisis, the war in Ukraine and tensions over Taiwan have dramatically changed the geopolitical context.
Here, Sky News looks at what you need to know about COP27.
When and where is COP27?
The COP climate talks change venue every year, with Egypt hosting COP27 on behalf of Africa in Sharm El Sheikh from 6 to 18 November.
The task of the host country is to rally other countries in the run-up to and during the conference to step up their climate action. Egypt should also try to build a consensus so that all countries can reach an agreement in the end.
Developing countries hope that Egypt, as a middle-income developing country, will provide a stronger platform for their demands as a host.
What is KS?
Every year, nearly 200 countries meet to discuss how to jointly tackle the climate crisis and its consequences. Thousands of observers, civil society groups and media are also present.
France hosted negotiations in 2015 that led to the historic Paris Agreement, in which countries agreed on the need to limit global warming to below 2°C, and ideally to 1.5°C, warming above pre-industrial levels.
COP stands for Conference of the Parties and refers to governments that have signed the United Nations Framework Convention on Climate Change (UNFCCC).
Who is participating in COP27?
According to Egypt, around 90 heads of state have confirmed so far, and US President Joe Biden is reportedly in attendance.
Britain refused to confirm whether Prime Minister Liz Truss would attend or whether Business Secretary Jacob-Rhys Mogg would go instead, which would have dismayed climate groups as he supports the expansion of fossil fuel use.
King Charles, who was known for his protection of the environment while Prince of Wales, refused to join after discussions with the Prime Minister, according to reports.
Why is COP27 important?
A key success of COP26 was that countries agreed on a more ambitious target of limiting global temperature rise to 1.5°C rather than the much more dangerous limit of 2°C.
But current policies are leading the world to about 2.4°C warming, with each fraction of a degree contributing to even greater impacts.
Although the COP is an imperfect process, it is the single largest geopolitical forum for countries to work out how to deal together with a threat that affects all of humanity.
What are the goals of COP27 and what will be the challenges?
While the world is falling short of its targets, Egypt wants to make COP27 purely an “implementation” of climate policy, but fears that geopolitical tensions and energy, food and climate crises will distract leaders.
Experts note that climate action can solve the energy, food and climate crises together.
Broken promises on cash will continue to plague negotiations. A target set by rich countries in 2009 to send $100bn (£89.8bn) a year by 2020 to poor countries to help them cut emissions and adapt to climate change has also so far been missed, prompting the wrath of developing countries.
Heavy flood that engulfed Pakistan revived the controversial issue on whether richer countries responsible for the vast majority of emissions should pay compensation to poorer countries, which typically pollute the least but suffer the worst effects of climate change.
Rich countries fear that paying compensation for such losses and damages will open the floodgates to future claims not only for climate impacts, but also about who should ultimately pay for damages in Ukraine or reparations for slavery.
Africa’s untapped gas reserves could be another “hot spot” at COP27, said Nick Maby, chief executive of think tank E3G, with countries divided over whether to use untapped gas or switch from fossil fuels to clean energy.
Campaigners routinely hold mass demonstrations during COP negotiations to put pressure on leaders.
But they fear that Egypt’s crackdown on environmental groups and government critics – tens of thousands are currently in prison – will prevent journalists, activists and civil society groups from attending COP27.
What effect will Russia’s war in Ukraine have on the negotiations?
COP negotiations rely on international cooperation and goodwill, with teams making commitments at the negotiating table in good faith that others will do the same.
Russia’s latest incursion into its neighbor has disrupted already shaky geopolitical relations and diverted attention from climate action at key diplomatic meetings such as the Group of 20 (G20) major economies and the United Nations General Assembly.
The ensuing energy crisis has changed the context of climate talks, and rising tensions between the US and China over Taiwan could also derail this year’s climate talks.
What happens every day?
The summit will begin with a two-day summit of world leaders who will fly in to demonstrate commitment and priorities for the process.
They then leave their negotiators to discuss the details in an effort to reach agreements on various issues by the end of the week. At no point this year will one comprehensive agreement be agreed, as was the case at COP26 with the Glasgow Agreement.
Meanwhile, conversations and events take place every day on one topic:
• Wednesday, November 9: Finance
• Thursday 10: Science and Youth Day
• Friday, 11: Decarbonization
• Saturday 12: Adaptation and agriculture
• Monday 14: Sex and water
• Tuesday 15: Civil society and energy
• Wednesday 16: Biodiversity
• Thursday 17: Decisions