Washington Post: As the centerpiece of Europe's pledge to lead the global battle against climate change, the region's market for carbon emissions effectively turned pollution into a commodity that could be traded like gold or oil. But the once-thriving pollution trade here has turned into a carbon bust.
Under the system, 31 nations slapped emission limits on more than 11,000 companies and issued carbon credits that could be traded by firms to meet their new pollution caps. More efficient ones could sell excess...