The Intergovernmental Panel on Climate Change found in a 2007 study that several factors will affect mass food production in the near future:
"Overall, food production is projected to benefit from a warmer climate, but there probably will be strong regional effects, with some areas in North America suffering significant loss of comparative advantage to other regions. The U.S. Great Plains/Canadian Prairies are expected to be particularly vulnerable. Climate change is expected to improve growing conditions for some crops that are limited by length of growing season and temperature. (e.g. fruit production in the Great Lakes region and eastern Canada)."
Climate change also has a widespread effect on plant growth: the behavior and aggressiveness of certain plant diseases and pests, adverse affects on beneficial insects, birds, and animals, the composition of soil, water quantity and quality...the list goes on.
When the cost of produce rises, it isn't necessarily due to a sudden freeze in Florida or a drought in California. The price of gas greatly affects food costs due to transportation expenses. Remember when something as small and light as a bunch of scallions was 3/$1?
If enough people would grow their own food, it would make a dramatic difference in energy demand, traffic congestion, and the emission of greenhouse gases.
(On a related point, produce that hasn't logged a bunch of "food miles" is better quality. It's fresher and isn't bounced around in transit. According to environmental writer Bill McKibben, 75% of the apples sold in New York City come from the West Coast or overseas, even though the state produces far more apples than city residents consume. Isn't that ridiculous?)
Here's a scary stat: The FDA inspects only about 1% of the imported foods it regulates, down from 8% in 1992 when imports were far less common. (The USDA, which regulates meat and poultry, is much stricter.) The FDA also doesn't require that exporting countries have safety systems equivalent to those in the USA.
Here's more from a story that ran in USA Today in March, 2007:
"The decline in FDA inspection resources has been pronounced in the past five years. While food imports have soared about 50%, the number of FDA food-import inspectors has dropped about 20%, the agency says.
"Meanwhile, more food imports come from developing countries, where pesticide use is often higher than in the USA, water quality is often worse and workers may be less likely to be trained in food safety, says Michael Doyle, head of the Center for Food Safety at the University of Georgia.
"A 2003 FDA study found pesticide violations in 6.1% of imported foods sampled vs. 2.4% of domestic foods. It has not been updated. Several years earlier, the FDA found salmonella and shigella, which can cause dysentery, in 4% of imported fruits and vegetables vs. 1.1% of domestic products."
A packet of tomato seeds will set you back, on average, about $3. Let's say 50% of the 100 seeds in the packet germinate and become fruit-bearing plants, and that each plant bears a minimum of 10 lbs. of fruit. That's 500 lbs. of fruit for $3.
Conversely, a bag of cherry tomatoes on the vine (about a dozen, if you're lucky) also costs $3.
Of course, when growing your own, you could calculate the cost of soil additives, tomato cages, canning supplies, water, mulch, etc., and the value of your time and effort spent tending to the plants, but I think the benefits are pretty clear.
My message is, of course: grow your own stuff. Climate can be controlled more effectively, unless you opt to have a large farm; the management of your food crops shouldn't be all that daunting. Cloth can protect from freezes as well as hot temperatures. Soil quality can be manually altered to your crops' needs. Everything -- including watering levels, pest and disease problems, etc. -- can be more closely monitored under your own watchful eye.
Best of all, you will know what - if any -- pesticides and fertilizers are being applied to your food crops, instead of being forced to buy mysteriously-produced food that wasn't safely grown or properly inspected.
Even a family of five doesn't need much yard space to host a highly productive garden. If you're pressed for yard space, use containers. "Vertical gardening" - training vines to grow up instead of spreading out - is also effective and efficient. If you have a yard, consider ripping out some of the grass and making it into a veggie garden. That lovely green lawn is a huge and unnecessary water waster anyway.
If you're a rookie to vegetable gardening, do plenty of research before jumping in. Learn what grows well in your area. Work to continually improve the soil. Read about crop rotation to ensure efficient production year after year. Can and preserve the wonderful food you've worked hard to grow so you can enjoy it all year round.
Lastly, if you absolutely don't have the time, space or energy to grow your own fruits and vegetables, please do your best to support local organic food markets. Check out the website localharvest.org to find the one closest to you.
IPCC, 2007: Climate Change 2007: Impacts, Adaptation, and Vulnerability. Contribution of Working Group II to the Third Assessment Report of the Intergovernmental Panel on Climate Change [Parry, Martin L., Canziani, Osvaldo F., Palutikof, Jean P., van der Linden, Paul J., and Hanson, Clair E. (eds.)]. Cambridge University Press, Cambridge, United Kingdom, 1000 pp.
Deep Economy: The Wealth of Communities and the Durable Future by Bill McKibben
http://www.usatoday.com/money/industries/food/2007-03-18-food-safety-usat_N.htm "U.S. food imports outrun FDA resources" By Julie Schmit, USA TODAY, Mar 18, 2007 © Copyright 2007, USA TODAY, a division of Gannett Co., Inc.