The development and use of clean technologies constitute a useful means of mitigating global warming. Although certain developing countries have become major emitters of greenhouse gases, they are not in a position to access the clean technologies that are prevalent in developed nations. In advocating technology transfers under the United Nations' climate change regime, developing countries argue that the intellectual property regime covering climate-related technologies must be ameliorated. In their proposals, they argue that compulsory licensing for clean technologies can be instrumental in furthering global access. This paper examines the legal issues associated with granting compulsory licenses for clean technologies. I analyze the legal challenges to authorizing such licenses, particularly in light of WTO/TRIPS and of national practices. An analysis of the previous practices surrounding the application of compulsory licensing reveals the severe hurdles facing competent national authorities and indicates the costs and burdens of such an action, which not every WTO member can afford. Jumping to the conclusion that the compulsory licensing of clean technologies is simply an illusory option may be premature; nevertheless, the legal barriers and burdens may dissuade developing nations from using such licenses injudiciously.