The looming shutdown of all nuclear plants in Japan after the Fukushima catastrophe might redirect the country's climate change policy, which was previously interrelated with a growing reliance on nuclear power. If Japan is to replace nuclear energy that used to provide nearly one-third of the nation's electricity, it has no choice but to increase the use of fossil fuels, for renewable energy constitutes a rather small portion of the country's energy mix. The growing use of fossil fuels has already increased GHG emissions in Japan, which is currently the fifth largest emission country in the world, and it also considerably affected global climate change negotiations and mitigation efforts. Japan’s current economic and energy situation might produce a negative effect on Tokyo's commitments to the targets of the Kyoto Protocol, and thereby on the future development of the global climate change regime. Despite the increase of investments made for the development of renewable energy, it will take substantial time to effectively replace nuclear energy and/or fossil fuels by renewable energy. Facing such challenges, Tokyo may demand a genuine commitment from the global community to proceed with the emission reductions set by the Kyoto Protocol as the condition for its further commitment and implementation of GHG emission reduction. Thus the Fukushima incident has restructured Japan’s energy policy and accelerated the ongoing changes in its climate change policy.