Barack Obama has arrived in Glasgow for COP26 as the second week of the climate conference gets underway.
The former US President signed the historic Paris Treaty in 2015, something he described as one of the "proudest" moments of his career.
However, in the four years following the end of his presidency, Donald Trump reversed many of the policies Obama had implemented.
With President Biden now in power, he is working to reintroduce many of the policies Obama's team, which Biden was a key part of, introduced between 2008 and 2016.
Six years after the signing of the Paris Agreement, Obama is back to address delegates at COP26 in Glasgow, having flown into Scotland on Sunday.
Here's what you need to know about Obama's speech at COP26 and how you can tune in...
What time will Barack Obama speak at COP26?
Former US President Barack Obama will speak at COP26 at around 2pm on Monday afternoon.
His speech is expected to last around half an hour.
The speech will focus on global warming and how to reduce CO2 emissions around the world.
While he will attend various events throughout the day, this will be the main speech.
Where can I watch Barack Obama's speech at COP26?
You can watch Barack Obama's address to COP26 delegates on the Sky News channel.
What will Barack Obama say?
The former president has seemed keen to connect with the youth at COP26, and he is likely to meet with young activists throughout the conference.
According to his spokesperson, Obama's speech will "lay out the important progress made in the five years since the Paris agreement took effect, highlight the leadership of young people around the globe, and urge more robust action going forward by all of us - governments, the private sector, philanthropy, and civil society."
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