Several recent analyses have concluded that the higher temperatures expected in coming years -- along with salt seepage into groundwater as sea levels rise and anticipated increases in flooding and droughts -- will disproportionately affect agriculture in the planet's lower latitudes, where most of the world's poor live.

India, on track to be the world's most populous country, could see a 40 percent decline in agricultural productivity by the 2080s

Africa -- where four out of five people make their living directly from the land -- could see agricultural downturns of 30 percent,

Latin America is poised to suffer reductions of 20 percent or more, which could return thriving exporters such as Brazil to the subsistence-oriented nations