As the polar ice melts, the weather patterns are changing. Some areas will become flooded while others will undergo drought and desertification. The declarations of a drought emergency in California on Feb 2009 and the 2008 heat wave in Portland, Oregon, droughts in Florida and Georgia are just the beginning. The meltdown of the arctic has reduced the cold arctic ocean currents off the west coast which is already causing droughts and heat waves. California is a major farming state producing a major supply of food products. Oregon has a large number of orchards. Florida is a major producer of Citrus products. Georgia is also a major food production state. Washington state is a major producer of Apples. The midwest is the main producer of grain products. I've seen drought kill the corn crops for 3 years in a row in nearby Texas fields. The next 2 years, the crops were destroyed by floods. That is 5 years of crops ruined. The local farmers have now changed to growing bird seed instead of human foods. Thus, this is yet another reduction in production.
In addition to the droughts and heat waves, we have had more severe freezes going further south than normal which has been damaging citrus and other crops. Right now, we are also depending on imported foods from Mexico, South America and China but the same weather problems which affect us, will also affect the global food production and supplies.
Once the sea levels rise, more and more food production will be affected by the weather, the droughts, the freezes, the flooding and the contaminated water as well as the loss of land both from the rising seas and the refugees seeking new homes inland.
To ensure you don't end up as a victim of food shortages, it would be a good idea for everyone to start some kind of garden and grow your own vegetables. Even one or two tomato plants in an apartment would be better than nothing.
It would also be advisable to start canning foods and start stocking a food pantry. Start this year. Don't wait until there is a shortage to begin storing a stockpile of foods which are nonperishable. Stockpiling drinking water would also be a good idea. Paper products is something else you may want to store. Shortages can affect a lot more than just food products. There are many factories which will end up under water and not a single attempt has been made to save any of the industries... and a large majority of industries are located in coastal areas.
Be sure to rotate your stored food products to keep them fresh. It also wouldn't hurt to store some powdered Gatorade as a backup source of electrolytes.
Also purchase quantities of mixed organic seeds as an emergency start for survival food crops.