President Donald Trump’s pullback from a global climate pact could accelerate China’s unlikely ascent toward leadership in stemming global warming and promoting green technology. The decision could have a similar impact on China’s role in global matters far removed from the environment. Trump’s announcement that the U.S. would leave the Paris accord immediately sparked international criticism, deepening perceptions of an America in retreat after recent reversals on free trade and foreign aid. China may be poised to fill the breach. The world’s largest emitter of man-made carbon dioxide is already making rapid progress toward its Paris goal of stopping emissions growth by 2030. It has overtaken the U.S. in transitioning to renewable energy. China remains heavily reliant on coal, and pollution is a persistent problem for its 1.3 billion citizens.