Try sleeping after a one-hour conversation with Kanayo Nwanze. The president of the U.N.'s International Fund for Agriculture Development is a perfectly affable guy, but his take on how climate change will lead to a fast-increasing number of violent uprisings and refugee crises that will dwarf Syria's always leaves me decidedly unsettled.

"It's clear if we don't recognize the signs earlier, if we don't make those crucial links, then poverty, migration, hunger and conflict will continue to make headlines," Nwanze said in Paris last weekend. With major climate change talks taking place in Paris, he's calling for "policies and investments that can pre-empt future crises."

We're talking mammoth problems. While estimates vary, the population of environmental migrants could hit 1 billion by 2050. Already, millions are on the move as rising world temperatures lead to out-of-whack climate patterns from droughts to floods to the frequency of storms. A Group of Seven report calls climate change the "ultimate threat multiplier" to the national security of nations big and small. Today's Syrian refugee surge overwhelming Europe is the tip of the proverbial iceberg.