Watch: US President Biden appears to doze off at global climate conference

The United Nations Climate Change Conference (COP26) has kicked off in the Scottish city of Glasgow, welcoming world leaders, experts and activists who will look for ways to slow down climate change.

Surrounded by foreign leaders, US President Joe Biden appeared to doze off while listening to the opening speeches on Monday.

As seen in a video circulating on social media, Biden closed his eyes for 22 seconds before an aide approached and roused him.

Before that, he had closed his eyes for about seven seconds, opening them and then nodding back off.

Washington Post journalist Zach Brown tweeted the video, which appears to show President Biden struggling to keep his eyes open as Eddie Ndopu, a disability rights activist, warned that global warming threatened “our ability to grow food and even to survive.”

Biden, 78-year-old, is the oldest US president in history. Critics, including some elected Republicans, have raised concerns about his frequent rhetorical missteps and refusal to engage with the press outside of taking questions from pre-approved reporters.