The meaning of sustainability 
The Population Media Center has posted an interesting article by Professor Emeritus Albert A. Bartlett about the meaning of sustainability. He makes a number of points, including: 
*Today we face two major global threats to our way of life [both related to and triggered by overpopulation]. The first threat is the peaking of the production (tons per year) of fossil fuels, particularly petroleum. The second threat is the rapidly developing global climate change. As these threats develop, each will have a profound effect on life as we know it. 
*Dumb growth destroys the environment. Smart growth destroys the environment.
*“Peak Petroleum” will cause rapid increases of transportation costs and thus make it more difficult to move fresh food half way around the world to the shelves in our supermarkets. Sustainability will require that the bulk of our food be produced locally near its point of consumption.
*We must seek to re-orient science, technology and engineering away from their present roles that support population growth and redirect them to work for more modest, less glamorous and less complex roles that can improve the quality of life for human beings. The model might be that which is found in the book Small is Beautiful by E.F. Schumacher.