An estimated 30,000 people will descend on Glasgow this weekend for the COP26 climate change summit.
There is a lot riding on it, with many seeing it as the last chance to curtail the growing climate crisis.
What is COP26?
COP26 is the next UN climate change conference that is taking place in Glasgow from Sunday, October 31, 2021 - Friday, November 12, 2021.
What does COP26 stand for?
COP stands for Conference of the Parties, and will be attended by countries that signed the United Nations Framework Convention on Climate Change in 1994.
The 2021 meeting in Glasgow is the 26th conference held, which is why 26 is in the name.
The Paris Conference in 2015 was called the COP21.
Where is it being held?
The event is being held for the first time ever in the UK, in Glasgow, Scotland's largest city.
Who is going to be at COP26?
Delegates from more than 190 countries will be attending the conference.
This also includes thousands of negotiators, interpreters, journalists and observer organisations.
UK politicians such as Michael Gove and Boris Johnston will be present.
US politicians John Kerry and President Joe Biden will also attend, this is significant after the former administration pulled out of the Paris Agreement.
The US Special Presidential Envoy for Climate, John Kerry is set to be a major part of discussions, and President Joe Biden will be at the event too.
High profile guests also include climate activists Greta Thunberg, broadcaster and natural historian David Attenborough and Pope Francis.
However, there has been some hesitancy on travelling during Covid, with Australian Prime Minister Scott Morrison stating he may not attend as he is focussing on reopening his country.
The UK has said it will be "very disappointed" if Prime Minister Morrison does not attend as Australia is the second largest coal exporter in the world.
The Queen set to miss COP26
The Queen will not be attending the COP26 climate change summit in Glasgow, after her medical team advised her to rest.
Why is the COP26 so important?
The COP26 has been described as a last attempt to curtail the climate crisis.
The conference will help countries decide how they can work together to fight climate change.
It will also examine how well countries have honoured their commitments under the Paris Agreement in 2015 to limit global warming to well below 2℃.
What about Covid?
The conference was meant to be scheduled for November 2020 but because of rising Covid cases it was delayed.
The Scottish government, the UN and the UK’s national government have all been working together to ensure precautions are taken.
The event was decided to be held in person, instead of digitally to help countries work together and make progress on climate change. There was a concern that if the conference was done online that it may be hard getting countries to commit to change.
People travelling from red list countries, will still be required to quarantine and delegates who have not been able to get the vaccine yet will be able to do so, at the UK's expense.