One author believes that population growth is the Cinderella story of the sustainability debate:

In practice, of course, it is a bombshell of a topic, with profound and emotive issues of ethics, morality, equity and practicability.

As found in China, practicability and acceptability can be particularly elusive.

So controversial is the subject that it has become the “Cinderella” of the great sustainability debate - rarely visible in public, or even in private.

In interdisciplinary meetings addressing how the planet functions as an integrated whole, demographers and population specialists are usually notable by their absence.

When I think and write about the idea of “sustainability” and how we might develop new standards of living, I see the effect of population at every turn. Causal lines seem to eventually lead back to this “bombshell” of a topic–that maybe there are too many of us. By 2100–93 years from now, a mere eyeblink, really–America’s expected to to have twice the population. The world population? Conservative estimates say ten billion or more in 2100, over 50% more humans than today.

Many people will argue the numbers–how many, how soon, steady or declining growth–but that’s missing the point. Unless the replacement rate drops to zero, we’ll have several billion more people on the planet in the next few generations.

Here in America, imagine having to provide water, food, energy and housing for three hundred million more people. Better yet, don’t imagine—it’s going to happen.

Here’s the bottom line, the part that worries me, the part that few seem willing to discuss: in a world of finite water and land where we’re already facing problems of energy shortages, eroding topsoil, ecological damage, increasing pollution, growing inequity, increasing corporate control of natural resources and a host of other seemingly ineluctable problems, how are we going to support billions of additional humans?

More simply: how could such a world ever be “sustainable”? Pollution (or CO2 emissions, or carbon, or however you want to describe it) is increasing yearly in every part of the planet–how can we not only have radically less pollution than today, but do it with three to six billion more people and millions of new buildings?

What’s to be done? Carbon trading? Slightly different purchasing decisions? Green roofs? Plant some trees? Biodiesel? Does society even regard human health as more important than profit? Will technology or innovation save us? Or maybe the creative class has some ideas? Here in Portland, urban planners plan for growth, artfully dodging the question almost entirely.

What do you think?