Nigeria's President Muhammadu Buhari is welcomed by French President Emmanuel Macron, left, before a lunch at the Elysee Palace in Paris, Tuesday, Dec. 12, 2017. World leaders, investment funds and energy magnates promised Tuesday to devote new money and technology to slow global warming at a summit in Paris that President Emmanuel Macron hopes will rev up the Paris climate accord that U.S. President Donald Trump has rejected. (AP Photo/Francois Mori)