Biden, as well as several other world leaders, wore a mask during portions of the multi-day virtual climate summit in April 2021. Biden, as well as other world leaders, did not wear a mask during every moment of this summit.
In April 2021, a picture started circulating on social media that supposedly showed how U.S. President Joe Biden was the only world leader who wore a mask during a virtual climate summit:
Although this does appear to be a genuine screenshot from the summit, it's incorrect to say that Biden was the only world leader to be wearing a mask.
For one thing, this picture shows less than half of the world leaders who attended the event. The "Leaders Summit on Climate" involved 40 world leaders, but the above-displayed picture only features 17 screens. The claim that Biden wore a mask for a "video call" is also misleading. Biden, as shown in the image at the top of this article, was not sitting alone in a room when he attended this conference. Rather, he was in proximity of other members of his team. In other words, Biden was wearing a mask for the safety of those in the room with him, not those on the video conference call.
It should also be noted that this screenshot shows a single moment from a multi-day summit. While Biden is the only one pictured here in a mask, we found several photographs showing other world leaders who masked up at various portions of this summit.
The following picture, for example, shows that Japanese Prime Minister Yoshihide Suga and Italian Prime Minister Mario Draghi were also wearing masks during portions of this video call.
https://www.gettyimages.com/detail/news-photo/april-22-2021-at-the-invitation-of-u-s-president-joe-biden-news-photo/1232476888
We reviewed various videos from this event, as well as photographs from Getty Images, Reuters, and The Associated Press, and found several other examples of world leaders wearing masks at various portions of the summit. Argentina President Alberto Fernandez, Indonesia President Joko Widodo, Singapore Prime Minister Lee Hsien Loong, and Prime Minister of Bhutan Lotay Tshering also wore masks during portions of this event.
It should also be noted that Biden did not wear his mask during the entire event. At some points, as shown in the picture at the top of this article, he listened to other world leaders while not wearing a mask. He also removed his mask while he addressed the other world leaders, as can be seen in the following video: