Leaders of the seven big industrial democracies embraced the environment with the zeal of the newly converted when they gathered in Paris for last year's economic summit. "This summit marked a watershed," President Bush said at the conclusion last year. "We agreed that decisive action is urgently needed to preserve the earth."

But the economic summit that begins in Houston today promises to accord the environment a lower priority. While issues such as global warming and rain forest destruction still have a place on the agenda, they are not expected to receive nearly as much attention as free trade and the political upheaval in the Soviet Union.

"I think this time we will see an economic summit that is focused to a far greater degree on economics," said Michael R. Deland, chairman of the president's Council on Environmental Quality (CEQ).

The anticipated focus on the Soviet Union and East Bloc economies is not surprising given the events of the last year. But the shift in emphasis has disappointed many environmentalists, who see it as one more sign that industrial nations -- and the United States in particular -- have failed to follow through on the bold rhetoric of 1989.

A coalition of environmental groups, meeting in the shadow of the Houston summit, gave the seven nations a mixed to poor review for their efforts during the last year.

"I'm a lot more depressed than when we got into this," said George T. Frampton Jr., president of the Wilderness Society. "Forests are being cut just as fast or faster than they were a year ago . . . . There has been virtually no progress on ocean pollution, and absolutely nothing on population. Overall, you'd have to say that these counties simply aren't treating environmental issues as an important priority -- in spite of the Paris communique."

Environmentalists cite as an exception last month's agreement by 92 countries to phase out production of chemicals linked to to the destruction of the earth's protective ozone layer. Government ministers also agreed to establish the world's first global environmental fund to help poorer countries make the transition to more benign varieties of chemicals.

But the industrial nations remain divided on a response to global warming, which scientists expect will be a consequence of the buildup of carbon dioxide and other greenhouse gases in the atmosphere. While Britain, the Netherlands and West Germany have established goals for reducing or stabilizing carbon dioxide emissions, Bush administration officials have avoided timetables in favor of continued scientific study.

Earlier this year, a panel of experts sponsored by the United Nations concluded that worldwide temperatures will rise 2 degreeswithin 35 years and about 6 degrees by the end of the next century if nothing is done to reduce carbon dioxide emissions. The report, based on the work of more than 300 climate experts worldwide, was seen as a vindication by environmentalists who have been urging quick action to combat the problem.

Environmentalists contend that by failing to follow the lead of Germany and other nations in setting goals to reduce greenhouse gases, the United States has forfeited its role as an international leader on environmental issues.

That charge was disputed by Deland, who said the nation already is working to reduce pollutants that cause global warming. "I don't think the U.S. has forfeited a leadership role and I think it's continuing to play such a role," Deland said.

But he also suggested that cutting greenhouse gases is easier for some countries than it is for the United States. "It's clearly much easier for West Germany to set such a goal," he said. "They can flick a switch and tie into French nuclear power . . . . We are clearly more tied to fossil fuels than many other countries that have alternatives such as nuclear and hydroelectric" power.

Many environmentalists had their expectations raised by last year's summit, in which participants devoted more than a third of their final communique to environmental issues. Pundits dubbed it "the environmental summit" and Bush even showed up with Environmental Protection Agency Administrator William K. Reilly, the first time the head of the EPA appeared at a summit.

A draft copy of the communique for this year's meeting reaffirms the global nature of environmental problems and addresses climate change, tropical forest destruction, marine pollution, wetlands loss and other topics.

According to the draft, worked out by advance teams from the countries involved, participants will agree on the need for an international convention addressing global warming to be held by 1992 under the auspices of the United Nations.

Participants also will consider the adoption of "internationally binding regulations" for the protection of tropical forests, which are being destroyed at a rate twice that of 10 years ago, according to the draft communique.

But the summit participants are expected to stop short of a specific, international commitment to reduce greenhouse gases by the end of the decade. "There aren't going to be any surprises," one administration official said.