Given how little we know about the dynamics of human population and the carrying capacity of our planet, the upbeat tone of your main leader is quite comical (“How to Deal with a Shrinking Population,” July 28, 2007). On the above, consider only the speed with which holes left by wars are replenished, including the right gender mix, or the consumption levels of our ancestors, who could live on almost nothing. But you get pretty ridiculous when you argue that climate change should be fought by consuming less fossil fuel rather than by manipulating population levels. Indeed, attempting to manipulate population levels without understanding population dynamics would be no less than crazy. We can only hope your upbeat tone will not entice anyone to try.