Since 1993, Henry has managed MassHighway's Wetlands Section. He is a specialist in environmental management and permitting. He also volunteers as a teacher in environmental stewardship at junior and high school levels.

There needs to be a better understanding on how the terms "sustainable" and "sustainability" should be used, especially since they are here to stay in the lexicon of the environmental movement.  But these words can lose their meaning amongst the “green” sound bites.  For example, although the phrase "sustainable growth" sounds reassuring, one could argue that it's actually an oxymoron.

The word "sustainable" can be traced back to the book "Limits to Growth" (Meadows, et al. 1972), and was drawn from the concept of "sustained yield," which is used to describe agriculture and forestry practices conducted in such a way that they can be continued indefinitely, i.e., the harvest yields can be sustained.  The terms "sustainable" and "sustainability" became commonly used in the 1980’s as the news media made people more aware of the growing global problems of overpopulation, drought, famine, and environmental degradation.

However, we now have a spectrum of uses for the term "sustainable."  At one end of the spectrum, the term is used to introduce profound concepts as they relate to the long-term future of humanity.  In the middle of the spectrum, the term is used to describe processes and methods that are relatively efficient, i.e., that conserve resources.  Near the other end of the spectrum, the term is used as a placebo.  As a type of “green-washing,” the term “sustainable” is often used to shed a favorable light on activities or products that are not necessarily designed to continue for very long periods of time.

In the context of society, a generally accepted definition of "sustainability" is where a society can meet their present resource needs without compromising the ability of future generations to meet their own needs.

A corollary of this definition is the formula that describes the impact of any group or nation on the environment: I = P A T, where P is the size of the population, A is affluence, measured by per-capita annual consumption, and T is a measure of the damage done by the technologies that are used in supplying the consumption.  This equation (attributed to Ehrlich and Holdren, 1971) is not rocket science.  Two billion people, all else being equal, put more greenhouse gases into the atmosphere than one billion people.  Two billion rich people disrupt the climate more than two billion poor people.  Three hundred million Americans consume more petroleum than 1.3 billion Chinese.  And driving an SUV uses transportation technology that is far more environmentally detrimental than riding mass transit.

Historical gasoline usage in America provides a good demonstration of this equation.  Despite steady improvements in fuel efficiency and engine technology (thereby reducing T), Americans’ annual fuel consumption rate is 60% greater now than it was in 1975.  This increase is due to a 41% growth in population (P), higher household incomes, and the number of cars owned (A) almost doubling (from 133 million to about 255 million).  Commuting distances also have increased due to people living farther away from work, where housing is more affordable and the quality of life oftentimes is higher (yet another manifestation of population growth).  In general, the more people there are, the more miles will be driven, and the more gas will be consumed (along with the associated emissions).  And even with advancements in technology, a rapidly growing population leads to greater rates of fuel consumption.

Another important principle is that the resources on "Spaceship Earth" are finite.  As has been true throughout history, the consumption of ancient non-renewable resources is not sustainable.  It's just that today, as our population streaks to almost seven billion, the rate of land development and resource consumption is unprecedented.  Furthermore, it has been demonstrated time and again that sustainability is impossible when faced with a growing population.

The United States is no exception.  Our nation is the fastest-growing industrialized country, and has the third-largest population in the world, behind only China and India.  In 1960, America's population was about 179 million.  It is now at 308 million, and in 30 years is projected to be 450 million.  This projected growth rate should be alarming to anyone who is advocating for "protecting the environment."  In fact, the effects of this population growth would influence the quality of life for today's kids far more than any lessons on "living green."  Certainly their opportunities to connect with the natural world would be diminished.

The leaders and educators of today must start the discussion on how fast our country should grow (if at all) and how could 150 million (or more) additional people be accommodated in a nation that already is experiencing resource shortages and degradation of farmland, water supplies, fisheries, air quality, beaches, rivers, parks, and wildlife habitat.  Perhaps the “growth is good” paradigm should be looked at more critically.

Ultimately, in order to move toward a sustainable society, the most important goal is to stop population growth.  This will require major educational, technical, and outreach programs in the areas of social responsibility, family planning, contraception, immigration, and resource use.  Specifically, environmental educators will serve a critical role in teaching that "population stabilization" is the primary factor for determining whether a society can achieve true sustainability.

By Henry Barbaro

References

Ehrlich, P.R., Holdren, J., (1971).  The Impact of Population Growth.  Science, Vol. 171, (1971), pp. 1212-1217.

Meadows, D.H., Meadows, D.L., Randers, J., Behrens, W.W., (1972).  Limits to Growth: A Report for the Club of Rome’s Project on the Predicament of Mankind.  Universe Books, New York City.