Environmentalists have been making a lot of "game over" predictions over the years. Fortunately for us -- and for the fortune tellers themselves, even if it has meant a loss of credibility -- none of them has become reality. Fifty years from now, human ingenuity will have translated into technological advances that are inconceivable today. So, let's stay positive instead of falling prey to the exaggerated nonsense of fear-mongers. We'll have a much better chance to find realistic solutions to the world's problems.