[zasz]

There will be a net loss to global agriculture for a couple reasons:

1. Climate change implies increased variability in weather--hotter summers, wetter winters. Agriculture does best in a relatively stable environment. Just look at California--extremely wet winters followed by extremely hot wildfires. It's hard for a species to thrive in a very wide variety of conditions. Not impossible, of course, with humanity being the crowning example of that kind of flexibility, but it's harder for an annual grain like wheat, rice, or corn to pull off.

2. Less sun at northern and southern latitudes mean a shorter growing season.

There are a few other reasons I can think of for why yields will generally drop, among them ozone pollution, but they're not related to climate change specifically.

[bsbechtel]

California is one of the most agriculturally diverse and productive regions in the world. I'm not sure what your point is, but implying agriculture struggles in California is just plain wrong.

[zasz]

I apologize, that part was poorly written. What I meant is that the kind of weather variation California's been experiencing will become the new normal, and the worse said variation is, the worse yields will become in general.