In This Issue
Sustainability Engineering
March 1, 1999 Volume 29 Issue 1

Sustainability Engineering (editorial)

Wednesday, December 3, 2008

Author: Robert A. Frosch

In the last 30 years, the thinking about environmental concerns has evolved considerably, from simply diluting pollution in air, water, or the ground, to controlling it at the end of the pipe to, most recently, managing ecoefficiently (maximizing both economic gain and environment performance). As we enter the 21st century, the notion of sustainability has taken hold. Sustainability challenges businesses and society to measure and value economic development in new ways. As I hope to show, it challenges engineers perhaps most of all.

Measuring progress toward a sustainable future is a daunting task. The difficulty increases as the boundary conditions expand. It is relatively easy to measure and manage inputs to and outputs from a single facility. The boundary is small and the time scales of concern are short.

On the other hand, extended product responsibility, which is based on the principle that suppliers, manufacturers, and consumers share responsibility for managing the environmental impacts of products throughout their life cycles, adds many new wrinkles. These include making environmental considerations part of the design process and encouraging companies to take back (e.g., for remanufacture) products at the end of their lifetimes.

Within the emerging mix of measures of environmental performance, there appear to be at least two tensions. The first is between the desire for comparability and standardization of metrics and the need for metrics to be applied usefully in specific situations. The second is between the desire for clarity and simplicity and the desire for metrics that capture complexities associated with a particular cause. As we further extend the boundary conditions to include the interaction of humans with environmental, infrastructure, and political systems, these tensions become more pronounced. To help resolve them, a systems approach is needed. Industrial ecology, a field the NAE has helped pioneer, is one such approach.

Industrial ecology involves the analysis of the flows of materials, energy, capital, labor, and information within production and consumption systems. It considers the impacts of these flows on the environment, as moderated by the influences of technological, economic, political, regulatory, and social factors. The objectives of industrial ecology are to better integrate environmental and social concerns in the design and management of industrial activities, and inform public policy decision making. While metrics and systems approaches such as industrial ecology are needed, we neither need perfect metrics, nor should we be paralyzed by analysis.

In thinking about sustainability, we must carefully balance our human desire to live as we please with an increasing set of political, economic, social, and environmental constraints. We do not want to destroy, or even to damage severely or irrecoverably, valuable natural resources (e.g., animal and plant diversity, forests, lakes). We depend on these for the materials (e.g., food, medicines, building supplies) and basic "services" (e.g., the regeneration of clean air and water) that make life on Earth possible and comfortable.

We know that we are changing or damaging key components of the biosphere, such as forests, waterways, fisheries, and the ozone layer. We do not always clearly know how to reverse or repair the damage. Population increases will place even more pressure on these resources. And no one can be satisfied at our failure to universally provide even a minimum standard of living for all people. Decent living standards are not only a humanitarian and ethical issue, they are also an economic one: Those who are financially secure and living in stable communities represent potential new markets for business.

The problems of the environment and of social and economic equity are interrelated, and their solutions are technological in nature. I believe that engineers and the National Academy of Engineering have a special role to play in this regard.

A particularly relevant example of the likely scale of the coming challenge is urban population growth. Current population trends suggest that by 2050, 6 billion people will be living in cities, three times more than today. Most of this growth will take place outside of the major industrial countries. This increase of 4 billion people works out to an average increase of 80 million people per year, the equivalent of 8 new megacities of 10 million people every year for the next 50 years!

This calculation does not take into account the infrastructure problems of our existing urban areas. Many have water, sewage, and street systems that were designed -- and largely built -- in an earlier era of smaller cities and older technology. Much of this infrastructure already suffers from massive shortfalls in maintenance and replacement.

How can we refurbish our older cities without undo disruption? How can we design and build or somehow assemble the equivalent of 8 10-million-person cities a year for the next 5 decades? How can we site such cities, or have them grow, without damaging the environmental systems they will need to provide their sustenance? These are engineering challenges of gigantic magnitude. Addressing them will require massive invention and innovation, and different and cheaper techniques, if we have any hope of paying for what we design.

Yet, megacities are only one of a dozen or so major technological or engineering challenges facing society. This implies considerable opportunity -- and responsibility -- for engineers. The human footprint is expanding as population increases and living standards improve. The trick will be to keep the footprint from stamping out the environmental values and services we need and want. We have our work cut out for us.

About the Author:Robert A. Frosch, a member of the National Academy of Engineering, is senior research fellow at the Center for Science and International Affairs, John F. Kennedy School of Government, Harvard University, and former NAE senior fellow. He chaired the NAE/National Research Council committee that produced the report, "Industrial Environmental Performance Metrics: Opportunities and Challenges" (National Academy Press, Forthcoming).