A recent technological breakthrough in Japan might soon render economically viable the large-scale exploitation of methane hydrates. The potential of this new (and global) form of unconventional natural gas is mind-blowing. Although a number of countries have already displayed strong interest in exploring their reserves, Japan is most likely to lead this new “dash for gas”. It has already made the development of methane hydrates an important element in its long-term energy policy. If Japan is successful, East Asia’s energy situation will undergo a dramatic change over the medium term, with worldwide repercussions. But it will not be good news for climate policy and the transition to a green economy.