I don't see us having a shortage of rice or corn here, just a rise in price, like everything else. That stuff is not critical to our diet (except as cattle feed) and we grow plenty. Corn and rice are easy crops for Americans to grow. It's mostly just a matter of economics. The price is going up everywhere, but to a 3rd world person ANY increase in the price of his rice (as an example) is disastrous. They will then riot, because they are paying all that they can afford to already. Even then most of their food is subsidized by their government, who gives them just enough to keep them from starving, so that they don't hang the government leaders. Always been that way. It will level off, as it always does.
At the moment the growers in those countries are keeping more of it for their own people. That is logical. They now have less to sell to non-growers, who will be hurting until they are willing to pay the extra cost, which always happens in a shortage, or grow their own, or substitute something else.
Rice and noodles are the base food item of China (up in Northern China it is the Idaho-type white potato and dumplings), but don't forget that a little less than a thousand years ago it was Millet (no one there ate rice in those days). Just a matter of convenience, availability, weather, water,etc. Hell, most of the plants and animals in the U.S. are not native to here. In early America most white folks ate Rye, Barley, and Oats that they brought from Europe, not corn or wheat.
An ear of corn was about the size of your fingernail back when the American Indians ruled the land. I've found lots of it dried and laying around in the areas where the Indians lived in Arizona. The large corn we have today is all hybrid and cross breeding is the only reason it is now that way.The people of India eat rice, but they also eat more tons of Chickpeas ("Garbanzo Beans"). It's cooked, mashed and spiced into foods like the dip, "Hummus." Dried, it stores well. http://en.wikipedia.org/wiki/Chickpea
Dal ("Lentils") is another vital part of their diet. It is a basic, nutritious, cheap, and tasty food, and does not need to be soaked before cooking. Drop into some Indian grocery store and check it out. There are lots of them around now. They sell it in large bags just like rice, wheat, and so on. http://en.wikibooks.org/wiki/Cookbook:Lentil I have stored dried Lentils and Chickpeas for years in exactly the same ways as I do wheat. In fact, I could do without wheat entirely (most people are allergic to it anyway). There are just too damned many alternatives around. Ground Lentil, Chickpea, Beans, etc., make great flour for tortillas, chapatis, pancakes, etc. (just as good and a hell of a lot easier to make than a loaf of wheat bread). Can make them easily right in a frying pan. http://www.motherearthnews.com/Real-Food/1978-07-01/Chapatis-Thats-What.aspx
Think 3rd world and you will never be without something good to eat. Store your favorite spices also (cumin, curry powder, chili powders, salt, etc.) to make them even more tasty. You don't need corn for example: It was not even heard of in the rest of the world until the white man came to this continent and found the natives using it.
In the U.S. the farmer now has a higher cost for petrol-based fertilizer and fuel to run his equipment. The trucker has a higher fuel cost to get the products to market, and our govt is printing unbacked money whenever it pleases them (to pay their debts, causing inflation for us).
These costs and inflation get passed on to us, the consumer. Eventually it will level off. Meanwhile the prices go up. Plenty to buy, but just more costly. Always been that way without a gold-backed currency, always will be. 10 years ago the price went up on most things, higher than in the previous 10 years, and so on back through history.When enough 3rd world peoples start to starve they will overthrow their leaders, or the number of eaters will be reduced. Either way it will level off eventually.Think variety for storing. You would get sick of an all rice, wheat, and corn diet pretty quickly anyway. It's all still a bargain at 3 times the price.