Scientists used to think the Amazon was too wet to burn, but a warming Atlantic Ocean is drawing moisture away from the rainforest

MOYOBAMBA, Peru – Karina Pinasco watched in dismay as flames on a hillside at the edge of town lit up the sky one night in October 2010. A farmer had intended to clear a few hectares of land to plant coffee bushes, but the fire – set during an unusually hot, dry spell – quickly got out of hand.

Propelled by winds and high temperatures, it burned for 10 days, charring more than 250 acres of land.