EU lawmakers on Tuesday called on Beijing to implement stricter checks on exports during their first visit to China in eight years. "We have repeatedly stressed that it is important for exports to be subject to stronger controls on the Chinese side," said Anna Cavazzini, chair of the European Parliament's Internal Market Committee, in Beijing.

"I don't know what's happened," the president said this week. "She's got some kind of an act going."

Carbon dioxide emissions trap heat in the atmosphere, warming the planet. Too much CO2 can disrupt the climate and oceans.