At Africa's first-ever climate summit in Nairobi this week, government and U.N. leaders sought to promote the continent as a source of solutions to the world's global warming challenge, rooted in its rich natural resources from sunshine to forests.

But they identified one big snag: a lack of finance to turn that potential into the reality of a green and fair transition.

"We must see in green growth not just a climate imperative, but also a fountain of multibillion dollar economic opportunities that Africa and the world is primed to capitalize," Kenyan President William Ruto told the summit.