in our earth matters series something we haven't seen in years world leaders including president biden gathering to discuss what to do about the climate crisis. and how to cope with the problems that it is already causing. cnn's phil black looks at the agenda for the upcoming climate conference in glasgow, scotland. >> reporter: these are just some of the biblical events the world has seen and experienced in 2021. extreme floods, fires, droughts, and record temperatures. across the u.s. and around the world. proof scientists say we're already living in a climate crisis. >> it's here. i mean, it is upon us. people see that. people feel that. >> reporter: he led the u.s. climate nosh jagrs through the obama administration and helped forge 2015's paris agreement.