Ten years ago the Club of Rome unveiled a report called "The Limits to Growth," using computer models to make grim projections about the future of humanity and the planet Earth. The remedy, declared the report, was a deliberate, worldwide move to slow the consumption of resources and fashion a "more sustainable" society.

Yesterday the club's U.S. contingent held a 10th anniversary get-together at the Smithsonian Institution, and 400 people addressed a painful irony: In the last decade, many of the terms and concepts of "The Limits to Growth" have worked their way into everyday parlance, while the alarming trends have simply continued. Some of yesterday's conferees met that dilemma with chins up, plans bold and rhetoric grander than ever. But others gave vent to a sense of pessimism and even resignation.

One of the darker pessimists was Elliot Richardson, whose long re'sume' of government posts made him a symbol of the American establishment to some in the audience. Richardson said he had seen the United States become "more consumption-oriented" in the last decade, and had decided that the world is simply too committed to growth to be rerouted by any methods other than "coercion." Democracy, he said, demands "we must reconcile ourselves to the political necessity of growth" while seeking "technological methods to offset some of its consequences." The best that environmentalists can hope for is "some present marginal sacrifice," he said, and that might not be enough to avoid "catastrophic overshoot."

Richardson's comments provoked an angry response from Donella H. Meadows, associate professor of environmental studies at Dartmouth College and coauthor of "The Limits to Growth." Richardson's alternates were "unacceptable," said Meadows. He gave "a very hopeless speech."

But even the optimists began from what might be regarded as pessimistic assumptions. "It is not possible to solve our problems if we do not touch on some taboos--national sovereignty, some aspects of economic growth, ideas about education," said Aurelio Peccei, the Italian businessman who founded the Club of Rome in 1968 and still serves as its president. Peccei said the "inner limits" of humans themselves would have to be confronted before they could properly address the basic questions of the environment and world social equity.

Some participants tried to find their good news buried in their bad news. "We are without any question in a revolutionary period," said Dennis L. Meadows, director of Dartmouth's Resource Policy Center and the other author of "The Limits to Growth." In retrospect, the '70s may have been a time of "premature concern for the environment without the willingness to pay the costs," he said. If so, current political trends could be a "backlash . . . a desperate effort to sustain physical expansion."

Even the "discontinuity" of human history was cited as cause for optimism. Disciples of Thomas Kuhn's "The Structure of Scientific Revolutions" professed to see signs of a coming "paradigm shift" in world thinking--away from material preoccupations and toward "the quality of life."

But there was general agreement that such a shift would require massive public reeducation. "Experience shows that we cannot rely on national and international leaders to take the initiative," said Russell W. Peterson, former governor of Delaware and now president of the Audubon Society. He condemned what he called the "use-it-up-and-to-hell-with-the-future ideology of the present administration," and said the Club of Rome, in alliance with other organizations, should hire a "top-notch staff of professional communicators" to "reach and convince the majority of Americans."

John M. Richardson Jr., professor of international affairs and applied systems analysis at American University, spoke of "how hard it is to find these decision-makers." Presumed leaders always turn out to be constrained by short-term agendas and constituencies, he said, so ordinary Americans would have to be persuaded to exercise "global leadership by example."

The club had expected to have a Reagan administration representative in the person of Robert D. Hormats, assistant secretary of state for economic and business affairs. But Hormats failed to appear, sending a subordinate, Paul Balabanis, in his place. Balabanis incurred the wrath of the audience with his stress on "the self-correcting mechanisms of the marketplace." The United States, he said, "has been by any measure the world leader in meeting" environmental problems.

A much less enthusiastic view of U.S. policy came from Victor Urquidi, president of El Colegio de Mexico, who said the United States "seems to have lost faith in the Third World, or has regressed to older attitudes of open domination." And despite all the international conferences on the North-South economic gap, "the North has not budged an inch," Urquidi concluded.