The term “sustainability” is being used with increasing frequency by policymakers, the media, scientists and the general public.

At many colleges and universities across the country, there is an outright fervor for creating “green” campuses. Indeed, campuses are now even ranked according to their “greenness.”

Here at Loyola, our administration has recently established a sustainability committee consisting of faculty, staff and students to evaluate and recommend “green” practices and operations on campus.

As a member of this committee, I have begun to ponder what sustainability really means and how we, as a campus community and as a society at-large, should conduct our affairs to achieve a more sustainable future.

In other words, what does it really mean to be “green?”

To begin with, let me say that sustainability is a very attractive concept, and I do not mean to denigrate or diminish efforts to achieve sustainability. The purpose of this essay is quite the contrary.

I believe it is our responsibility as stewards of the environment to pass on to future generations a planet that is fully capable of supporting the myriad of life that includes humans and another 10 million or so species.

But, we do need to know what sustainability is before we can say with any confidence that we are making progress in our efforts.

One way to think about sustainability is to use a related concept, the carrying capacity, developed and used by ecologists.

In ecology, the term “carrying capacity” is used to describe the upper limit of population size that the environment can support indefinitely.

In other words, according to this definition, sustainability occurs when we meet the needs of the current human population without compromising the environment for future generations.

But what does it mean to “compromise” the environment and how do we know if we are undermining prospects for future generations?

To fully appreciate the magnitude and depth of our challenge we must understand this idea of compromising the environment and its sustainability components, and ask ourselves where we stand now, and what it will take to reverse the environmental changes already underway.

Sadly, the collective body of evidence from many diverse fields of science now convincingly tells us that we humans are using natural resources faster than they can be renewed and we are polluting the world more than we can clean it up.

We are not even close to living in a manner that is sustainable over the long-term.

For example, we now consume over half of the earth’s renewable fresh water and half of the primary productivity on land.

We have lost 50 percent of our topsoil. We have increased atmospheric carbon dioxide levels, the primary culprit of climate change, by over 30 percent in the last 200 years.

Our most important commercial fisheries in the oceans are on the verge of collapse due to overfishing. We are contributing to the extinction of species at rates far above natural “background” rates.

Today, for the very first time in the history of Earth, a single species (ourselves) is changing our planet’s climate.

And, to make matters worse, these impacts will only accelerate as our global population increases (we are currently above 6.7 billion and growing) and more and more people around the world strive to live like average Americans.

So, the challenges facing us to achieve sustainability are great.

What then are the practical solutions to achieve sustainability?

What, specifically must we do here at Loyola and within our larger global community to become “green”?

Paul W. Barnes is a professor in the biology department, the chairman of environmental studies and holds the J.H. Mullahy S.J. endowed chair in environmental studies. He can be reached at [email protected]. This is part one of a two part
column.