What is COP26 and why does it matter?

UN climate summits have always carried hope that world leaders would use COPs to finally unite against climate change. But even when they succeeded, like in Paris 2015, climate activist Greta Thunberg says most of what comes out of the event is "blah, blah, blah" because we miss crucial targets to prevent global warming from 1.5 degrees Celsius above pre-industrial levels. In fact, experts tell us that now we're heading toward a 3 degrees Celsius scenario, which would be catastrophic for both nature and humans. And if global cooperation has failed on vaccinations, why is climate going to be any different?

Watch this episode of GZERO World with Ian Bremmer: Surviving a warming planet