When I recently returned from a trip to California I took something with me that is very precious to that state, something that is causing all kinds of problems for California, but is absolutely essential to everyone and everything in California. I filled my water bottle in the airport and took it with me. Chances are the water actually came from Nevada, but that is beside the point. The point is that California is in a debilitating drought. Green things are hard to find now in California: grey and brown dominate the landscape. Flying over California is flying over a desert.
The drought affects everybody in California and is developing into a threat for society. Other parts of the country look to California for policies because they experience equally dramatic conditions. The southwest of Oklahoma is one of these areas.
Arguably, the drought is being caused by Global Change, is at least partly human induced. Another effect the water crisis has is a lot less visible: the lack of water on the surface and in the ground is changing the geology of California. Just like the melting of the glaciers removed so much weight from the land that it uplifted after the last ice age, California is now showing crustal uplift as shown in a recent study that appeared in the journal Science (http://www.sciencemag.org/content/345/6204/1587.full). Truly humans are changing their environment here!
Another aspect of the drought may have even more dramatic effects later: as we deplete the drinkable surface water, more and more water is pumped out of the ground. A depleted pond will fill up again after a good rain, but it takes a very long time to replenish our aquifers. What we are doing is not sustainable and at the cost of future generations. We are drinking the water of future generations and by doing so we may render the land uninhabitable.