The Wall Street Journal reported soaring prices for chocolate due to a shortage of cocoa beans and a surge in demand (more people want healthier dark chocolate, which requires more beans per treat).
Mentioned in the article is drought that threatens 2014 crops. Cocoa beans presently only grow in a range 15 degrees North and South of the Equator. Cocoa beans are somewhat fragile. Political unrest, war and drought affect production. In the past, beans have been grown in the shade of other plants within tropical rain forests. Deforestation to grow substandard cocoa more quickly and burgeoning chemical use are also issues for sustainable chocolate production.
Shade-grown cacao plants take three years to mature enough to produce beans. So, though climate change might allow beans to grow in different places, it would take three years to reach success.
Green America has produced a movie called The Dark Side of Chocolate about how chocolate is farmed and the child labor often used to grow and harvest it. Green America also has a chocolate scorecard.