What would happen in North America if California became drier?

Question

My question is mainly related to the impact on food production if the climate changes made agriculture more difficult in the state of California but also in the other American and Mexican states from both side of the border.

Context: If you live in the United Sates, in Canada or possibly in other countries as well, you might have noticed all the food produced by this region while shopping in the grocery store. They produce most of the fruits, vegetables and nuts that we eat:

California produces a sizable majority of many American fruits, vegetables, and nuts: 99 percent of artichokes, 99 percent of walnuts, 97 percent of kiwis, 97 percent of plums, 95 percent of celery, 95 percent of garlic, 89 percent of cauliflower, 71 percent of spinach, and 69 percent of carrots.

The problem: The climate changes are making the Hadley cell larger. The northern limit of that cell is dry. Right now, California is affected by this dry pattern only during the summer. While winter are more humid due to the influence of the polar front. South of the border,in Mexico, we have Baja California. It is mostly a dry desert because it is always affected by a dry weather. My guess is that the expansion of the Hadley cell could lead to the desertification of southern California and other states along the border.

• If the region suddenly became more arid, what would happen to the food production?
• Could farmers adapt to the drier climate with different crops or different agricultural techniques?
• Would the climate changes simply move the food production more to the north and could these states adapt to replace the lost production from the south?

For more information about how climate works : Creating a realistic world map - Currents, Precipitation and Climate

Answer 1

Won't comment on the weather patterns causing it...I think the Colorado river being drained prior to California is more likely:

Food production

From what I know of California, is the majority of the crops there are already high heat and low water crops. Had the water flow from the Colorado river halted, I would assume we would first see a few years of failed crops and unusually low yields and the prices of a few items exclusive to California to shoot up (somewhat like we've seen in Turkey of recent with the Hazelnut wipeout almost eliminating Nutella production). Honestly, if you look at most of the crops, none of them are really native to the region and are there artificially because we have put them there and irrigated them so they could grow.

Wine might be the most resilient just due to the amount of interest and wealth involved will ensure those grapes keep irrigated. We would see shortages and increased costs of particular fruits/veggies that are heavier on water consumption go up first, and the disappearance of a lot of these items on restaurant menu's across north america. I'm not sure if it'll ever fully fail, there is enough water coming downstream to California that even if it becomes much drier, irrigation will still happen.

Reversely, there are certain crops that would thrive in these changes. Almond Tree's give their best yields in exceedingly dry hot summer and wet winters...so although certain crops that heavily rely on irrigation may start to falter, other harvests could potentially see some bumper crops and increased yields from these climate changes.

Could farmers adapt to the drier climate with different crops or different agricultural techniques?

They've adapted to some pretty dry conditions already and I'm not sure how much further you can adapt...it's just a matter of getting water to those fields. My guess is the issue in the comments of the Colorado river being diverted prior to California would become a major political issue US wide and not just in California.

Would the climate changes simply move the food production more to the north and could these states adapt to replace the lost production from the south?

I wouldn't say north...northern California is redwoods and the territory doesn't get much agriculture friendly north of that. I would suggest further inland...sadly this is basically saying we'd go further up the Colorado river and farm there instead.

Arizona...Yuma county in particular...is already known as America's winter salad bowl. It produces the majority of the greens consumed in winter months across north America. None of this production is really native to Arizona, but the intense sunlight coupled with irrigation means we can grow pretty much anything there.

Answer 2

Even if California dried up completely,we would not suffer much more than slightly higher prices for the produce. Production will move to places where it is more profitable, and more imports will come in. Production processes will adapt, as with everything else. We already produce more than enough food as it is, and California is not the only place where food will grow.

They could even survive significantly drier climate if farmers switched from flood irrigation to drip irrigation - that alone would save massive amounts of water (at the cost of investing in drip irrigation systems).