A crash course in changing the world.
Here's a website run by some local Lads who are big on the allotment scene here in Bristol, the idea being that if you can't be totally self-sufficient in a city, you could try to be selfsufficient-ish www.selfsufficientish.com
In the Uk we dont have too many people starving through lack of food, our biggest problems are quality of diet (particularly amongst the poorer members of society) and a reliance on (mainly African) imports, and last I heard the Africans were in pretty dire need of that food themselves. There is obviously not a simple solution to the problem of reliance on imports in a country as densely populous as the UK, but their are steps we can take to improve our diet and reduce our reliance on imported grain.
Step 1: Embrace 'kitchen gardening' in all its varied forms, this is not always easy in a city environment but I think we could take some good cues from the Cubans (Huertos - http://www.youtube.com/watch?v=jRz34Dee7XY) in that regard. There are many benefits to people pursuing this sort of activity, beyond increased food security;
1. Regular light excercise has been shown to be one of the corner stones of a long healthy life, along with a balanced, low(ish) calorie diet containg the very things you are growing.
2. Growing plants is immensely rewarding, and also has benefits for mental health.
3. Green cities, not grey ones.
Step 2: Farm Extensively, not intensively. We can't allow this trend of liquidating the resources of the natural world to feed our ever increasing population to continue.
Step3: Embrace technology, innovation and increase our knowledge about the natural world at large.
http://www.ted.com/talks/lang/eng/barry_schuler_genomics_101.html <- a talk for foodies, thought it would be a decent perspective for this post.