Biden falling asleep at climate conference

Biden seems uninterested and extremely tired as shown in the video. As the speaker proclaims this is the most important issue facing our times (as believed by the left and democrats) Biden seems to exude a lackluster interest in the issue.

It does raises questions about the viability of a president that is 79 years old and who has claimed he is tested regularly for cognitive decline; whether he is up for the job.