Reuters: The U.N.’s climate change agency on Wednesday proposed to make it more difficult for speculators to earn carbon offsets from emissions-cutting projects which were already profitable. Under the U.N.-run Kyoto Protocol, industrialized nations can meet limits on their output of planet-warming gases such as carbon dioxide by funding emissions cuts in the developing world in a scheme called the Clean Development Mechanism (CDM). The scheme is meant to cut the world’s overall output …