The future for Brazil's mighty farm sector could be grim, with hotter temperatures pushing crops past its borders, uphill into the Andes and toward the tip of South America.

Experts in tropical agriculture are developing genetically modified coffee, soy beans and other crops that can withstand higher temperatures in Brazil's expanding northeastern desert, new pests and diseases and more flooding in low-lying areas.

That could mean a 10 percent reduction Brazil's arable land for coffee by 2020 — and a one-third reduction by 2070 — as the crop's suitable climate migrates into the Andean foothills of neighboring Argentina

Brazil's coffee plantations extend across 5.7 million acres (2.3 million hectares) and produce more than twice as much as the next-largest grower, Vietnam.