There is more interest in self-sufficiency during this 21st century than ever before. That blatantly tells you that people are feeling the effects of the environment around them. We're not talking about "good" effects either. We're talking about chemicals in the food we eat, pollution of land, water and the air we breathe. This also includes finite natural resources that's becoming scarce thus driving the cost up as demand for it continues, etc. In general, health issues have been on the rise due to a combination of all these things which drives the desire to make certain changes in one's lifestyle.