At a recent meeting in Japan, the leaders of the developed world are moving towards an agreement to cut global greenhouse gases in half by 2050. However, they haven't agreed on what level they'll be cutting in half  ? current, or 1990 levels of emissions. Was it all a lot of hot air? Living on Earth turns to Elliot Diringer, Director of International Strategies for the Pew Center on Global Climate Change for an analysis of the meeting, and a look ahead.