 Hello, I'm Peter Armstrong. And I'm Chris Howden. Coming up on As It Happens. What if Joe did, in fact, go? We'll take a long, hard look at what the process of actually putting a new Democratic candidate on the U.S. presidential ballot would involve. And the world's largest wetland is in flames. A region of Brazil valued for its biodiversity is experiencing the worst wildfires it's seen in years. A biologist working there explains what it's like to witness the effects firsthand.