Basically just verifying and rehashing what has been known for over 20 years----that CAGW will cause crop failures in one out of three years, from all causes related to CAGW.
There are other problems as well, from soil depletion from a variety of causes, from organics loss to salinization. Then there is aquifer depletion which cuts production to 1/6th of previous. The Ogallala is best known and studied, but the process is countrywide (also with the San Joaquin and Columbia Aquifers) and global.
Food production and distribution will also be affected by oil prices and scarcity, with people doing much more local growing of all their nutritional needs. Where they are not met will result in malnutrition diseases and lowered immunity, along with starvation and water deaths from impurity or lack.
2050 sees half the food production(of 1990-2000) with fisheries depletion added in. Average food in 1993 was 1600 calories per person per day with 5.4 billion, so before 2050 it will fall to below sedentary starvation level average. Of course averages mean some will have more and some less. The population will rapidly decline, taking with them everything locally possible to eat.
From my post on the "Blue Blob" thread: "In the end, so called intelligent humans are no smarter than yeast in a bottle of sugar water. On average, of course."http://www.skepticalscience.com/No-alte ... -down.html
and this;http://www.ipsnews.net/2013/02/thawing- ... l-warming/