This paper illustrates first what the government of Japan intends to do with a few official pledges on mitigating global warming, such as the action plan and the famous idea of New Earth 21 program, toward long term stabilization of CO2 concentration in the air. In practice, however, there are a number of factors which may disturb realization of the targets envisaged in these plans. Limitation to advancement of further energy conservation, not only in industrial sectors but also in other sectors where individual consumers play key roles, is certainly serious. Another crucial factor is the nuclear power. Recent accident at the experimental FBR, Monju, has influenced the public acceptance of nuclear power very seriously, and the government is now at the stage of re-designing the future scenario of nuclear power, taking into account both the opinions in favor of nuclear and those of anti-nuclear. Nevertheless most of energy experts believe that nuclear power is safe and also economical enough to be maintained for the intermediate future at least in Japan so that strong policy measures are to be introduced to improve public acceptance of nuclear power. The second pan of this paper describes the future of so called ＇＇new energy＇＇ which the government of Japan is eager to develop and also the limits to development of these ＇＇new energy＇＇. The third pat is contributed to description of R&D of long term technological options and also difficulties in realizing these options. It is also worth noting that Japan, both government and industries, has much interest in CO2 removal from flue gas of power plants and its disposal.