Al Jazeera: A study of derelict Pennsylvania oil and gas wells has spotted what is possibly a huge source of additional greenhouse gas emissions.
Methane, which is pound-for-pound a much more potent climate-warming gas than carbon dioxide, could be leaking from hundreds of thousands of abandoned wells. And thats just in the Keystone State. A growing body of evidence says countless old wells across the country -- most poorly monitored -- could be belching up the same dangerous emissions.
The study by Mary...