Since the beginning of 21^st century “Science Communication” or “Public Engagement of Science” is a fashionable word in Japan. The background of this trend is a great socio-historical change in relation between science (and technology) and society in the developed countries. The symbolic message of this change will be found in the Budapest declaration (1999) witch states “science in society/ for society” as a new mission of science, in addition to the traditional mission such as science for knowledge. This paper explores the implication of this change for Japanese society and suggests that a new mission of philosophy of science is emerging by examining the IPCC report. The conclusion of this paper will be that science communication is not only informing scientific knowledge understandably to public but promoting discussion on the significance of present day science and technology for society and philosophers of science should contribute to it.