[buwaya]

Its likely to do the opposite actually. Colder weather = lower yields on the whole.

The warmer=lower yields analysis is badly off I think.

[21twelve]

A geologist acquaintance of mine was concerned about global cooling. As one of his hobbies he tinkered with strains of wheat somehow, and had developed several cold-weather strains and sent them to various universities (Sweden was one) to have them researched and developed.

I would hope that others have done the same with other crops, and for both warmer and colder varieties.

[RobRoy]

A warmer planet is a wetter planet. And I would think places like Canada and Russia would get greater wheat production.