South Korea likes to point the finger at China for its pollution woes, but that's not the whole story. New research is examining how much Korean smog is caused by neighbors and how much is home-grown.
Indian cities are among the world's most polluted. And India is the third-largest emitter of carbon dioxide. If it finds a sustainable way to develop, it could be a template for the rest of the world.
Pigeons have a bad reputation. But London's Pigeon Air Patrol is monitoring pollution levels. A flock of racing pigeons equipped with sensors launched this week. The results, naturally, are tweeted.
Even the combined deaths from HIV/AIDS and malaria isn't quite as devastating. The culprits are the usual suspects, like cars and industry, but also cookstoves and ... manure?
In polluted Pittsburgh, a new device from a local university helps residents assess indoor air. It's not the only monitor on the market — but is the only one available to borrow from a public library.
Officials released the details of the state's proposed $225 million settlement with ExxonMobil, calling it a historically large payout. But environmentalists say the deal is worse than they feared.