Yale Environment 360: In what could prove to be a momentum-setting piece of diplomacy, the United States and China which together account for a third of the planet's greenhouse gas emissions jointly announced plans to pursue significant cuts in those emissions over the coming 10 to 15 years. Among the details of the joint pledges, unveiled as part of meetings this week between Chinese President Xi Jinping and U.S. President Barack Obama in Beijing, were commitments from the U.S. to cut its CO2 emissions by between...