Conclusion of a series on tackling poverty while protecting the environment.

A few months ago, I awkwardly asked MacArthur Genius and environmental geographer Ruth DeFries, “How do we solve poverty?”

Her eyes bugged, she laughed in my face — and then she gave me some insightful pointers. For the last year, I’ve been asking those kinds of big, dumb questions about an impossibly big challenge: How the world could end poverty without wrecking the environment.

I’ve learned that while no one has a prescription for ending poverty, history at least shows what’s worked in the past. It provides some boundaries around the realm of plausible solutions.