For business leaders, it's a question about billions of dollars - maybe even trillions - in potential profits and losses

Donald Trump has often ridiculed global warming and promised to withdraw the United States from the global accord signed in Paris in 2015. Yet despite the change of political weather in Washington, the captains of business and finance gathered in Davos this week will spend a lot of time talking about climate change - and how to make money from it.

The World Economic Forum is devoting 15 sessions of its 2017 annual meeting to climate change, and nine more to clean energy - the most ever on the issues.