Faced with a U.S. retreat from international efforts to tackle climate change, European Union officials are looking to China, fearing a leadership vacuum will embolden those within the bloc seeking to slow the fight against global warming.

While U.S. President Donald Trump has yet to act on campaign pledges to pull out of the 2015 Paris accord to cut greenhouse gas emissions, his swift action in other areas has sparked sharp words from usually measured EU bureaucrats.

When Myron Ebell, appointed to lead Trump's transition team on the environment, took to a stage in Brussels on Wednesday and called climate experts "urban imperialists," a rebuke from Britain's former energy minister drew applause from the crowd packed with EU officials.