LJWorld.com weblogs Global Warming from a Conceptual Standpoint
I have some simple observations to point out.
The human population is rising, and it is rising faster all the time. I don't think I need to provide supporting references for this; it should be common knowledge.
Heat waves are becoming more common. "This hot extreme, which covered much less than 1% of Earth’s surface during the base period, now typically covers about 10% of the land area." This is happening globally. The hot spots are not always in the same place; sometimes it will be us, sometimes Europe, China, and/or Russia (notably in 2010, which had some fallout starting with food riots in Tunisia in 2011). The area they cover is on an upward trend globally.
The heat wave and drought that the midwest experienced last year lowered yields per acre. Not all Kansas counties were affected equally, but "Statewide, the corn yield averaged 96 bushels per acre, down 11 bushels from 2011 and the lowest Kansas corn yield since 1983." The drought and heat were worse in the west than they were in the east.
Farmers are not stupid. They have done a very good job of optimizing food production. They have first selected the lands best suited for agricultural production, and only as demand has grown have they expanded into less productive acreage. Not only are highly unusual events becoming more common, but climate zones are shifting in general. The combination of these changing factors is going to make yields per acre become less optimized, and less optimized production implies either less product, or higher prices for the same amount of product.
Since we live on a finite earth, rising population would be a problem at some point regardless. What I'm saying is that it would be less painful to deal with an increasing population if our ability to grow food were not decreasing at the same time. The least we can do is quit pretending we don't have a problem; that's just deluding ourselves. Some people are called alarmists, I call them them realists. On our current path, our future is "Cloudy with a chance of war".