Investors have trillions to fight climate change. Developing nations get little of it

At this year's U.N. climate conference, a major focus is boosting investment in developing countries. Experts say renewable energy projects like this wind farm in South Africa can be attractive to private investors. (Rodger Bosch/AFP via Getty Images)

One of the thorniest issues at the United Nations' annual climate negotiations in Egypt is how to get money to low-income countries to help them cope with climate change.

Governments of industrialized countries, whose emissions have largely driven global warming, have pledged help. But public funds alone can't cover the trillions of dollars developing countries need to deal with rising temperatures.