By doing what? Going to ballgames? Driving F-250's? If you believe that, I have some oceanfront property near Cleveland I'd like to sell you. I suppose that "we" could destroy the "biosphere" (whatever you want to define that as) by mass detonation of nuclear weapons. Short of that, it would be pretty damn hard to do. Modern industrial and post-industrial economies are the cleanest they've been since the industrial revolution got going full bore. There is more forest in the continental U.S. than there was 100 years ago. The economic systems doing the bulk of polluting (Soviet bloc countries) have closed up shop. Under current trends, the human impact on the "biosphere" is nothing but UPside, baby. Cavort with the cockroaches all you want, but human progress, at least from an environmental standpoint, will march on without you.
Haven't you heard? Cleveland is not only the "best location in the nation" it is also the "capitol of the North Cost".8^)