During the last four or five months I’ve taken a guided look at some of our biggest environmental problems—population growth; chemical exposure, including pharmaceutically active compounds; and global warming. Throughout I have relied, perhaps too heavily, on facts and the perspective provided by Bjorn Lomborg ~2001! in The Skeptical Environmentalist. Lomborg’s main points are: ~1! The world isn’t as bad a place to live as some people are saying; ~2! Or, if it is that bad—half the world’s population lives on $2/day or less, etc.—the direction of change in our collective condition is positive; ~3! In any case, there is no good reason to weaken the economic engine on which progress depends in order to pursue other objectives; and ~4! Our social and environmental objectives need to be prioritized so that expenses on their behalf make sense. These points, if I have them roughly correct, are in contrast to much of the discussion that centers around the World Summit on Sustainable Development, which is ongoing ~as I write! in Johannesburg. Although I’m guessing here, most of the thousands who went to Johannesburg would probably say that the developed world is at least partially responsible for the obvious problems experienced by less developed nations—through resource and labor exploitation, weapons sales, and the intemperate use of the world’s natural resources and sustaining ecological systems. The positions and philosophy of the United States government on the global environment is, to say the least, much closer to that of Lomborg than to the spirit of the Johannesburg gathering. So much so, that we opted for a pretty low profile at these meetings. Suppose we take these two positions as the bases for debate. Who is correct in the main? In most respects, Lomborg’s arguments appeal to engineers like me. He uses our language and analytical approach to problem solving, emphasizing the relationship between costs and benefits to identify economic and social efficiencies. He cites data that are available to all of us in the information age in order to build arguments. If his arguments are flawed in any specific respect, he invites discussion leading to resolution, although within an institutional framework that reflects the ideas outlined immediately above. That is, the money that we spend on social and environmental objectives should be justified like any other rational purchase and prioritized, acknowledging the finite nature of our economic means. So what, if anything, could be wrong with this picture? Does Lomborg’s view, for example, ensure that we will collectively choose a sustainable path for our planet and its resource base? Jerry Taylor ~2002!, director of resource studies at the Cato Institute, decided to deflect this issue by arguing, as did Lomborg, that in many respects our activities in pursuit of economic objectives have expanded the world’s resource base. He and others feel that growth in human per capita consumption is infinitely sustainable ~Barbier and Homer-Dixon, 1996!. The basis of this argument is that through application of human ideas we are capable of expanding the ability of the environment to serve human purposes.