Converging Nano and Nature: Ensuring Environmental Sustainability

George Nassos, Ph.D.

As nanotechnology innovation and commercialization hurdle forward at an ever-increasing pace, it is crucial that social responsibility and sustainable development keep up. The Center on Nanotechnology and Society's (Nano & Society) Chicago Nano Forum considers, in its ongoing public dialogue, how the big issues facing the environment can be addressed by this nascent science that works on such a small scale.

"An Age-old Analogy

To better understand how the environment has changed over the course of time, one must look back over the Earth's 4.5-billion-year history. A view through a lens analogous to the Biblical story of creation provides an interesting and provocative perspective. Though this analogy, Earth's complex evolution is simplified according to a seven-day timeline so that we might come to terms with the significant environmental damage that has occurred to the planet during humanity's relatively short history. The analogy of creation starts on Monday with the Earth's creation. On Tuesday morning, the basic elements of life begin to emerge. Then, not much happens until Thursday, when photosynthesis starts to occur. On Friday, there is oxygen, chlorophyll, and coal. Then, on Saturday afternoon, giant reptiles appear, and they are joined by primates on Saturday evening. It is not until 11:59:54 p.m., six seconds ago according to this analogy, that Homo sapiens ultimately appeared. What has happened to the environment in those last few seconds has significantly changed the health of the planet and put the future of the environment at great risk.

There was a time when all environmental changes occurred naturally. Major climatic events, as well as long ages of hot and cold, have had their impact on the planet. However, the introduction of modern industrial and agricultural practices has altered the climate far more rapidly, and with unsettling effects - including global warming. Studies from the National Academy of Sciences show that the Earth's surface temperature has risen by about 1 degree over the past century, with accelerated warming in recent years.¹ What is more, there is substantial evidence to show that much of the warming is caused by human activities, such as the build-up of greenhouse gases from power plants and automobiles.

How Much Does "Six Seconds" Cost?

Nevertheless, the full extent of global warming may not be realized because of the masking effect of a little-known phenomenon called global dimming. Human activities that emit substantial amounts of particulate matter, such as jet plane exhaust (called contrails), reduce solar irradiance from reaching the Earth's surface.² Global dimming keeps the Earthıs temperature lower than it would otherwise be, but it does not reverse the long-term and permanent environmental damage caused by air pollution, and, in fact, is just another form of such pollution.

However, action can be taken to curb further damage and, even, perhaps, remediate the damage already done based on how we opt to proceed with nanotechnology R&D. For example, nanotechnology applications may improve environmental monitoring and develop cost-effective site remediation capabilities. Nanotechnology applications may also lead to "green manufacturing," preventing pollution, and eliminating waste and dependence on nonrenewable energy.

Nano "Biomimicry"?

One answer may lie in biomimicry. The emerging field of biomimicry, which views nature as "model, mentor, and measure,"³ is premised on the notion that nature, imaginative by necessity, has undergone billions of years of "experimentation" in the process of perfecting what "works," and, that, as a result, science can gain insights into solving technical challenges from the designs and processes found in nature.

Some key examples of how biomimicry could be employed include learning from:

• plants' use of photosynthesis to build solar cells;
• spiders' spinning of pliable silks (from soluble, renewable materials) that are five-times stronger than steel;
• abalone, with an inner shell that is very smooth but hard as nails, composed of a hexagonal structure that withstands stress far better than modern ceramics; and
• mussels, which create a strong adhesive that is insoluble in water.

Is It Sunday Yet?

By the analogy of creation, "the day of rest" has not yet arrived. Nanotechnology is one of the top research priorities of the U.S. government and of many other nations in the developed world. With commitment to employing human ingenuity for the protection of the environment, rather than its degradation, nanotechnology may provide a key to unlocking and reproducing nature's most enduring achievements in a manner that is both socially responsible and environmentally sustainable.

¹ See http://yosemite.epa.gov/oar/globalwarming.nsf/content/climate.html.
² An unexpected and unfortunate course of events allowed scientists to measure the negative effect of jet plane exhaust on the environment. The grounding of planes after September 11, 2001, temporarily reduced contrails; the resulting increase in temperature provided empirical evidence of the effect of jet exhaust on the Earth's surface. David J. Travis, Andrew M. Carleton, & Ryan G. Lauritsen, Contrails Reduce Daily Temperature Range, 418 NATURE 601 (2002).
³ See http://www.biomimicry.net/intro.html.