Donald Trump has questioned the science behind climate change and committed the United States to withdraw from the Paris agreement, raising concerns that the US contribution to international climate funds will cease (see also Nature http://doi.org/bs57; 2016). This could cause some of the least-developed countries to lose interest in the Paris process and make many of its essential elements much harder to implement.

The Paris agreement is supposed to start its first review in 2018 — a process that is already fraught with political difficulties that call for strong leadership from the United States, Europe and China. If the United States pulls out and Europe is distracted by problems such as Britain's upcoming exit from the European Union, it could cement China's position as a leader and shaper of global order.