Earth Summit Ends on Optimistic Note : Environment: Leaders declare confrontational meeting a success and urge quick action.

The Earth Summit, the first global conference of the post-Cold War era, declared itself a success and adjourned with barely a murmur of dissent here Sunday, its leaders saying that speedy action will be necessary on several fronts to preserve its momentum.

“We’ve got a basis for change, but we have got to push like hell to make sure that it takes place,” said Maurice Strong, a former businessman from Canada who served as secretary general of the unprecedented conference joining the rich and poor nations.

By the time Brazil’s President Fernando Collor de Mello gaveled the final session to a close, 153 of the 178 nations represented at the summit had signed treaties designed to protect the Earth’s biological diversity and to address the threat of global warming.

Because the treaties were completed before the conference began June 3, most of the actual negotiations in Rio focused on the 800-page “Agenda 21” environmental action plan and on ways for industrial countries of the Northern Hemisphere to provide financial aid and modern technology to developing nations.

Agenda 21, U.N. Secretary General Boutros Boutros-Ghali told the concluding session, stands to be “the centerpiece of international cooperation for many years to come.”

Still unresolved, however, is the overarching issue of how much money the developed countries will provide to help poor nations protect their environments while proceeding with development and economic expansion.

Strong said that plans announced here could add up to several billion dollars a year in new environmental aid “if countries live up to their commitments.” Among announcements at the summit were Japan’s pledge to spend as much as $7.7 billion on environmental aid over the next five years, a European Community offer of $4 billion over a similar period and a U.S. promise of $150 million a year to protect tropical forests.

In the end, the summit reaffirmed a longstanding U.N. objective of having developed countries contribute 0.7% of their gross national products to official development assistance.

Developing countries had pressed for a year 2000 target for the commitment, but with time running out, negotiators compromised on providing the aid “as soon as possible.”

Such a commitment would require the United States to triple its foreign aid budget, but the Bush Administration took the position that it is unaffected by language that “reaffirms” the target because the United States has never “affirmed” it in the first place.

By U.N. estimates, it will take as much as $125 billion a year in new aid to fund the Agenda 21 action plan, a sum that Strong said will only be possible through innovative financing such as pollution taxes and user fees.

As delegates adopted Agenda 21 and the Rio Declaration of sustainable development principles, the only formal reservations were entered by Saudi Arabia and Kuwait, who regarded Agenda 21 language as threatening to their oil economies.

With other major oil exporters, they earlier had succeeded in watering down the language, but they were left isolated when the United States opposed their efforts to weaken the section further.

It was one of the few times that the United States--the subject of intense criticism because it declined to sign a biological diversity treaty--was cheered at the conference.

U.S. delegate E. Curtis Bohlen, the assistant secretary of state for oceans, environment and science, called the Agenda 21 plan, reaching several decades into the next century, “an almost-revolutionary document.”

The United States took a dimmer view of the Rio Declaration, which it earlier had threatened to try to change. It especially disliked a “right to development” clause, officials said, because it said the wording could be interpreted as a license to abuse human rights. In the summit record, the United States will enter a unilateral interpretation of the paragraph.

With the summit closed, Strong obliquely criticized the United States for undermining the global warming treaty and for taking other positions that environmentalists viewed as obstructive.

North America, he said, is leading a lifestyle of heavy consumption and resource use that cannot be sustained.

“I am not a doomsayer by nature,” he told reporters, but the world “is on a course that leads to tragedy.”