The Greening of America has been under way for more than 20 years, but recently there have been signs that the movement is entering a new phase:
At McDonald's Corporation in Oak Brook, Illinois, executives of the world's largest food-service chain banished most polystyrene packaging in 1990, opting for recycled paper instead, and committed to spend $100 million annually for the purchase of recycled products to build, remodel and operate more than 9,000 U. S. restaurants.
In Lawrence, Kansas, Wal-Mart this spring opened the first in a series of ''Eco-Marts,'' featuring renewable construction materials, highly efficient lighting and a recycling center right on the premises.
For a site overlooking Baltimore's Inner Harbor, directors of the Living Classrooms Foundation plan to build a $950,000 Environmental Education Pavilion where children from schools around the region can learn about the Chesapeake Bay.
These are just a few examples of ''Green Architecture,'' environmentally sensitive construction projects that are taking shape in response to the growing public concern about the fragile state of the planet.
Bombarded almost daily with news of pending environmental disasters -- from global warming and ozone depletion to acid rain and endangered forests -- more and more Americans are joining the effort to reverse the cycles of destruction.
Sounding the clarion call for action in the United States is Vice President Gore, a passionate defender of the environment long before he reached that office. In his 1992 best-seller, ''Earth in the Balance,'' Mr. Gore made the point that man has become a ''co-architect'' of nature and possesses the power either to harm or heal the planet.
''If we do not see that the human part of nature has an increasingly powerful influence over the whole of nature -- that we are, in fact, a natural force just like the winds and the tides -- then we will not be able to see how dangerously we are threatening to push the earth out of balance.''
Now, Vice President Gore and other environmentalists are gaining strong allies in the nation's architects, designers and other building-industry professionals. Increasingly, they are realizing that one of the best ways to help the natural environment is to change the way the built environment is designed -- and that the changes can be good for business, too.
Around the country, architects are discovering that the growing public awareness of environmental issues has important implications for every phase of the design process, from siting and materials selection to use of more energy-efficient technologies.
They are responding with ''green'' buildings that are not only politically correct but that in many cases turn out to be less expensive to operate in the long run and more healthy to occupy.
In some cases, the main impetus is cost savings. In others, it's an idealistic client who wants to set a positive example. Whatever the motivation, the increasing number of high-profile projects for companies such as Wal-Mart provide solid evidence that eco-conscious design is no longer an esoteric specialty practiced by a select few architectural ''greenies.''
The Green Architecture movement has had its advocates since the 1970s, when solar panels and other energy-saving devices were touted as part of the Back-to-the-Earth movement. But many of the suggestions were aesthetically unappealing and never took hold either within the profession at large or with the general public.
One of the important differences between today's Green Architecture movement and the one in the 1970s is that 20 years ago, architects were asking clients to give up modernity. The new effort is not about giving up, but about giving back and making only the trade-offs that are absolutely necessary.
As a result, today's sustainable-design movement ''has a salable element that appeals to developers,'' said James Wines, a veteran green architect. ''It saves money for property owners. It may cost more in the beginning, but it saves them money in the long run.''
The roster of participants in the so-called ''Green Architecture'' movement now includes such respected mainstream designers as Frank Gehry, Henry Cobb, Robert A.M. Stern and James Stewart Polshek, and multidisciplinary firms such as Ellerbe Becket; Hellmuth Obata Kassabaum, and Baltimore's own RTKL Associates.
The Green Architecture movement is getting its biggest push ever this weekend as the American Institute of Architects and Great Britain's International Union of Architects meet in joint session in Chicago to focus on the delicate balance between natural and built environments.
Led by Earth Day organizer Denis Hayes, Australian futurist Peter Ellyard and American Institute of Architects president Susan Maxman, participants will issue a worldwide call for architectural sustainability.