54-year-old swimmer and climate activist Lewis Pugh became the first person to swim the entire Hudson River, arriving in New York City for climate week, after swimming in it 50 years ago amid its pollution. He joins Andrea Mitchell to discuss how toxic waterways can be revived, and that clean rivers are essential to clean oceans. “This would have been impossible fifty years ago. But then in the 1970s New Yorkers said enough is enough. And they started cleaning up the river, and literally mile by mile, town after town and factory after factory, and they turned the fate of this river around,” Pugh says. “Rivers are the arteries of our planet, and we cannot have a healthy planet without healthy rivers.”