Fifty years ago this question had hardly been asked by anyone. Today it is common to hear it asked. So what has made the difference?
I recall, some forty-three years ago, having lunch in a park in Sydney where I could see an every-changing electrical sign. The sign depicted just two sets of data: the rate at which forests were being denuded worldwide, and the rate at which the world's populations was growing. It was frightening to see how constantly and quickly the figures were changing.
So what can we do to use our renewable resourses smarter? The very best way - and the biggest challenge - REDUCE THE WORLD POPULATION OF HUMAN BEINGS!