Sustainable Architecture Can Help Reduce Carbon Dioxide Emissions

Carbon dioxide is in the air like never before, but not just as measurable parts per million in the earth's atmosphere. Increasingly the subject of everyday conversation and cultural discourse, rising CO2 emissions are seen by many as no less a threat than terrorism, uncontrolled immigration, avian flu or escalating gasoline prices.

A new exhibit on green architecture at the National Building Museum contributes to the discourse. Atmospheric carbon dioxide and its planetary consequences are what former vice president Al Gore talks about in the documentary, "An Inconvenient Truth."

Carbon dioxide was also the focus of a presentation at last month's conference, "The Architecture of Sustainability," sponsored by the American Institute of Architects national committees on design and on the environment.

Addressing the conferees packed into the Corcoran Gallery of Art auditorium, New Mexico architect Edward Mazria delivered a sobering, persuasive opening presentation about carbon dioxide and global warming. He also delivered a daunting challenge to architects: Design all new buildings, whatever the type, to use half the fossil fuel energy used now by buildings of that type.

By the year 2030, the goal is for new buildings to be "carbon-neutral" and use no energy from fossil fuels that produce greenhouse gases. This means that less than 25 years from now, ideally no oil, coal or natural gas would be burned to build, heat, cool and light new buildings.

The 2030 challenge (see http://www.architecture2030.org/) is predicated on the fact that buildings and the construction industry account for about half the energy consumed in the United States. Thus Mazria contends that architects, responsible for designs of a substantial portion of new projects as well as renovation of existing buildings, could contribute significantly to reducing carbon dioxide emissions.

Innovations could include configuring buildings to be heated, cooled, ventilated and lighted more efficiently; specifying green and recycled construction materials; buying renewable energy while harnessing solar, wind, geothermal and biomass energy; and exploiting available and emerging energy technologies.

Mazria acknowledged that attaining the 2030 objective would not be easy, especially because it requires changed attitudes and behavior in sectors of the building industry beyond the influence of architects. It also requires that public attitudes and behavior change. Nevertheless, he thinks architects could exercise more leadership than in the past.

Before exhorting architects to take the lead and meet what he sees as the profession's most pressing design challenge, Mazria convincingly displayed charts, graphs, maps and photos documenting the scientific rationale for worrying about carbon dioxide. He set forth facts and observations, most of which are familiar but are rarely presented coherently.

Fossil fuel depletion: Given known petroleum reserves and rates of accelerating consumption throughout the world, oil could be depleted in about 42 years and natural gas in about 64. Coal eventually would be the only fossil fuel. This assumes marginal increases in use of renewable energy sources.

Atmospheric carbon dioxide: Today, atmospheric carbon dioxide measures about 378 parts per million, compared with about 300 parts per million 450,000 years ago. Yet by 2100, carbon dioxide content could be as high as 700 parts per million. Most of this projected increase would be attributable to continuing use of fossil fuels for buildings, construction, transportation and manufacturing.

Climate change: Carbon dioxide is called a greenhouse gas because it traps solar heat within the atmosphere. Having the effect of a greenhouse's glass roof, carbon dioxide prevents this heat from radiating back out into space. Trapped atmospheric heat is absorbed by the earth's surface, slowly raising the temperature of water, land and vegetation.

Quantitative estimates vary, but scientists generally agree that global warming is a reality, asserting that even a one-degree Celsius increase in average global temperature would make the earth warmer than it has been in the past million years. More alarming, a rise of two to three degrees Celsius is conceivable, and perhaps unavoidable, by the end of the 21st century.

Consequences of climate change: Mazria described the likely catastrophic effects of progressive global warming if temperature forecasts prove accurate. Melting polar ice would raise sea levels, inundating tens of thousands of miles of coastland and displacing tens of millions of people around the globe. Much of Florida, the Gulf Coast and Maryland's Eastern Shore would disappear.

Hurricanes and storms would be more frequent, more severe and longer-lasting. Water for farming, industry and cities would diminish, as lakes and rivers become warmer and more evaporation occurs.

Agricultural productivity would decrease, forest fires would increase and both wildlife and vegetation would vanish or relocate.

As humans, animals and plants migrate in response to rapidly changing conditions, disease will move with them. Thus, public health could be as worrisome as flooding.

After stating the scientific case and voicing the 2030 challenge, Mazria added an appropriate epilogue about the need to make sustainability an integral part of architectural education. In many architecture schools, he pointed out, sustainability is still viewed by both faculty and students as optional.

But I would extend Mazria's exhortation. Sustainability concerns everyone, not just architects. All students everywhere, from elementary school onward, must learn what is happening to the earth and what must be done about it. Without informed citizens and clients, architects will never meet the 2030 challenge, no matter how many green buildings they design.

Roger K. Lewis is a practicing architect and a professor of architecture at the University of Maryland.

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