Agence France-Presse: China, deemed vital to the fight against global warming, is now taking the issue of climate change “extremely seriously,” EU Commission chief Jose Manuel Barroso said Friday. Meanwhile US President Barack Obama had effected a “sea-change” on environmental policy there, he said. China had become “fully and constructively engaged in the international negotiations, while domestically it was pursuing very ambitious targets to reduce energy intensity by 20 percent under its current …