"At some point when things are not really moving, it's better to have a failure than a foul compromise," Leipold said.

Greenpeace still hopes for limited success, with renewable energy one area likely to produce results, since even modest concrete steps can have a major impact in desperately poor countries, he said.

Greenpeace demands the summit launch a plan to bring clean energy to two billion poor people who lack electricity and agree on a target that 10 percent of primary energy supplies come from renewable sources such as solar energy.

"There's a general recognition that poverty is linked to access to energy," he said. "If we look back on our Western societies, energy was a motor of development."

But prospects for a significant overall agreement are bleak since the United States is dead set against a pact containing concrete targets, he said.

Envoys from 25 nations gather in New York next week to search for a last-minute accord for the summit that starts on August 26, South African and U.N. officials said this week.

Preparatory talks last month for the summit, which seeks to push forward goals agreed a decade ago at the Rio de Janeiro Earth Summit, ended in acrimony with rich and poor nations split on an action plan to slash poverty and protect the environment.

If the high-profile summit falls short of expectations, it will at least raise the profile of environmental concerns and put further pressure on governments, Leipold said.

"What can be expected now will be so embarrassing for governments... If they only come out with nice words and voluntary agreements, the disappointment will be huge," Leipold said.

RAYS OF HOPE

Although Leipold said the immediate outlook for progress on major environmental issues was gloomy, he detected a glimmer of hope for the longer term.

The September 11 attacks in the United States have allowed Washington to shift the public focus away from environmental issues in its war on terrorism, he said.

And in Europe, a neo-liberal ideology that plays down the government's role in solving problems such as environmental degradation has gained strength with the rise of right-of-centre governments in countries such as Denmark, France, Italy, the Netherlands and Portugal.

But the public is growing increasingly aware of the failures of unbridled capitalism evidenced by the surge in corporate scandals such as Enron and WorldCom, Leipold said.

"The question of what is the public good and who serves the public good is coming back very, very powerfully.

"In the short term the outcome is depressing, but the question and the demand for it will come out stronger after Johannesburg."

Although there has been only scant movement since the Rio summit in 1992 on major environmental issues such as cutting greenhouse gases to curb global warming, progress has been achieved in other less-noticed areas.

"We haven't made progress on the real big issues - climate change, deforestation, overfishing - but on other levels there has been huge progress. The increase in environmental legislation is one of the big success stories," Leipold said.

In the corporate arena too, the environment has been accepted as a key issue, largely due to pressure from the public.

A decade ago the person responsible for environmental issues in major companies was in the public relations department in order to gloss over any problems such as toxic spills, but now that responsibility usually lies at director level, he said.

Even a company like oil giant Exxon Mobil Corp , against which Greenpeace is campaigning because of its stand opposing the Kyoto accord on global warming, has been making moves within the firm to increase energy efficiency to save money.