A person gestures as people protest during the UN Climate Change Conference (COP26), in Glasgow, Scotland, Britain, November 10, 2021.

Protesters set off a siren opposite the UN Climate Change Conference (Cop26) venue in Glasgow Scotland, November 11, 2021.

British Prime Minister Boris Johnson and United Nations Secretary General Antonio Guterres in conversation during arrivals for the UN Climate Change Conference (COP26) in Glasgow, Scotland, Britain November 1, 2021. Christopher Furlong/Pool via REUTERS

Sir David Attenborough delivers a speech during the opening ceremony of the UN Climate Change Conference (COP26) in Glasgow, Scotland, Britain November 1, 2021. Jeff J Mitchell/Pool via REUTERS

Britain's Prince William (not pictured) and Catherine, Duchess of Cambridge celebrate the Scouts #PromiseToThePlanet campaign during a visit to 105th Glasgow Scouts, at the Alexandra Sports Hub, on the sidelines of the UN Climate Change Conference (COP26) in Glasgow, Scotland, Britain, November 1, 2021. Victoria Stewart/Pools via REUTERS

Britain's Prime Minister Boris Johnson greets France's President Emmanuel Macron during arrivals at the UN Climate Change Conference (COP26) in Glasgow, Scotland, Britain November 1, 2021. Alastair Grant/Pool via REUTERS

COP25 President Carolina Schmidt hands over the presidency of the UN Climate Change Conference to COP26 President Alok Sharma in Glasgow, Scotland, Britain, October 31, 2021.

A delegate attends the UN Climate Change Conference (COP26) in Glasgow, Scotland, Britain, November 9, 2021.

A general view of the UN Climate Change Conference (COP26), in Glasgow, Scotland, Britain November 12, 2021.

A delegate attends the UN Climate Change Conference (COP26) in Glasgow, Scotland, Britain November 12, 2021.

Britain's Prime Minister Boris Johnson arrives on an electric bus with other leaders and attendees for an evening reception to mark the opening day of the UN Climate Change Conference (COP26) in Glasgow, Scotland, Britain November 1, 2021. Alberto Pezzali/Pool via REUTERS

Climate activists dressed as world leaders take part in a "Squid Games" inspired protest during the UN Climate Change Conference (COP26) in Glasgow, Scotland, Britain November 2, 2021.

Signs are seen as people take part in a vigil during the UN Climate Change Conference (COP26) in Glasgow, Scotland, Britain, November 10, 2021.

U.S. former President Barack Obama attends the UN Climate Change Conference (COP26), in Glasgow, Scotland, Britain, November 8, 2021.

A delegate attends the UN Climate Change Conference (COP26) in Glasgow, Scotland, Britain, October 31, 2021.

Climate activist Greta Thunberg speaks at a Fridays for Future march during the UN Climate Change Conference (COP26), in Glasgow, Scotland, Britain, November 5, 2021.

Indigenous people attend the Fridays for Future march during the UN Climate Change Conference (COP26), in Glasgow, Scotland, Britain, November 5, 2021.

European Commission's Vice President Frans Timmermans shows a picture of his 1-year-old grandson, Kees, as he speaks at the UN Climate Change Conference (COP26), in Glasgow, Scotland, Britain November 12, 2021.