Reuters: A freak tornado and floods last month may be a harbinger of a troubled future for Brazilian farmers, who worry that climate change could severely disrupt production in one of the world’s breadbaskets. Rising temperatures, a shift in seasons, and extreme weather in coming decades are likely to cut output in some areas and wipe out crops entirely in others, experts say. “Brazil is vulnerable. If we don’t do anything, food production is at risk,” says Eduardo Assad, an agronomist …