Related Links: Platts News and Analysis International Energy Association The US shale gas revolution is unlikely to be replicated elsewhere in the world, and its international impact is most likely felt through an increase in liquefied natural gas supplies to the global market, the head of the International Energy Agency said on June 20.Speaking in St. Petersburg, Russia, Executive Director Maria van der Hoeven said there were major obstacles that would impede the development of shale gas in Europe and China.Paris-based IEA, made up of 28 member countries, is a resarch and advocacy group for reliable, affordable and clean energy,