An article in New Scientist tells us how to survive the 21st century, what with climate change and all.
There’s a paragraph on agriculture ((The links are provided as in the original article. I didn’t add them myself.)):
Since water will be scarce, food production will need to be far more efficient. Hot growing seasons will be more common, meaning that livestock will become increasingly stressed, and crop growing seasons will shorten, according to David Battisti of the University of Washington in Seattle and his colleagues (Science, vol 323, p 240). We will need heat and drought-tolerant crop varieties, they suggest. Rice may have to give way to less thirsty staples such as potatoes.
The interactive map also has stuff on agriculture. Check out in particular Southern Europe, where, apparently, “[a]lthough agriculture will be largely impossible, hardy animals such as goats will be kept on the fringes of the desert.”