This paper uses the EPO/OECD World Patent Statistical Database (PATSTAT) to provide a quantitative description of the geographic distribution of inventions in 13 climate mitigation technologies since 1978 and their international diffusion on a global scale. Statistics suggest that innovation has mostly been driven by energy prices until 1990. Since then, environmental policies, and climate policies more recently, have accelerated the pace of innovation. Innovation is highly concentrated in three countries--Japan, Germany and the USA--which account for 60% of total innovations. The innovation performance of China and South Korea together represent about 15% of total inventions.