The global environment summit concluding Friday, which drew nearly 100 world leaders and more than 45,000 other people to Rio de Janiero and cost tens of millions of dollars, may produce one lasting legacy: Convincing people it’s not worth holding global summits.

The U.N. Conference on Sustainable Development, a once-a-decade meeting aimed at reconciling economic and environmental aspirations, has produced a nonbinding declaration, committing the world’s politicians to modest goals. The proposals set out at the beginning, such as providing universal energy access and doubling renewables by 2030, have been left on the cutting-room floor.

“I don’t know if they’ll ever do this again, and I don’t know if we’ll need it again,” said the Pew Environment Group’s director of international policy, Susan Lieberman. She said she was at least pleased that oceans received more attention this year. “It’s a 12-ring circus here.”

The so-called Rio+20 Earth Summit has featured plenty of theatrics, including Greenpeace’s unfurling Thursday of an “Arctic Scroll,” signed by legends such Paul McCartney and Robert Redford, to be planted on the North Pole seabed to draw attention to global warming. And it has hosted dozens of serious policy discussions.

Conservation International Vice President Carlos Manuel Rodriguez said he was encouraged that Scandinavian leaders pledged support for systems that would place an economic value on clean waterways, intact forests and other important ecosystems.

“This is helping countries make changes that are transformational,” he said.

And Maldives President Mohamed Waheed announced at the summit that his nation would ban damaging fishing practices.

“It helps us broaden the understanding of situation of small island countries like the Maldives,” he said in a phone interview.

Ecuador’s secretary of state, Ivonne Baki, who is trying to recruit donors to compensate her nation for protecting its Yasuni National Forest rather than extracting the oil beneath it, said she was pleased more than 500 people came to her presentation in Rio.

“It gives an example to the world of a developing country doing something to preserve one of the most biodiverse places in the world, the Amazon,” she said, adding she cares more about securing funds for Ecaudor’s project than U.N.-brokered promises to help poor nations which never materialize. “What we need is results, not just signing documents.”

There is no question that both companies and countries have used the gathering, with tens of thousands of attendees, as a moment to make new environmental pledges. Grenada announced its transport and electricity sectors will only use clean energy sources by 2030; the corporation Unilever promised to cut its greenhouse gas emissions in half by 2020 and find sustainable sources of beef, soy and palm oil to prevent the deforestation now stemming from production of these three major crops.

Still, both veterans of the international process and some of its newest participants are wondering if such negotiations can produce meaningful outcomes.

Manish Bapna, acting president of the World Resources Institute, said the combination of “strong-vested interests” and the need for unanimous approval in the United Nations has led to a final agreement which reflects the “lowest common denominator.”

The text that world leaders are poised to ratify Friday deleted or weakened dozens of phrases at the behest of various countries, according to an analysis by Center for American Progress special assistant Adam James. The Vatican prevailed by striking the phrase that leaders recognize “access to reproductive health services” is important to gender equity and women’s empowerment. A separate passage calling for the expansion of renewable energy includes the sweeping caveat that it should be“based on individual national circumstances and development aspirations.”

“I think this process is totally broken,” wrote Melinda Kimble, the U.N. Foundation’s senior vice president, who as a State Department negotiator helped forge the 1997 Kyoto Protocol on global warming. “While we are searching for a new paradigm to advance international cooperation, this meeting is definitely not a model.”

Brittany Trilford, a 17-year old New Zealander who won a contest to attend and represent global youth in an address to the assembled delegates, said she was shocked by the final product.

“This doesn’t look very ambitious, and it doesn’t look like it will do anything,” she said. “Everyone you talk to is frustrated about what’s going on. Everyone is tense.”

Kimble and other experienced negotiators such as Yvo de Boer, who previously oversaw the U.N. Framework Convention on Climate Change, said the summit had been hampered by the economic downturn as well as a lack of preparation and shared vision about how the world should tackle its long-term problems. President Obama skipped the meeting, as did British Prime Minister David Cameron and German Chancellor Angela Merkel.

Secretary of State Hillary Rodham Clinton addressed delegates Friday, in Obama’s place.

In her speech, Clinton spoke of forging partnerships that would harness “the power of the market” rather than relying solely on governmental action. “So while the outcome document adopted here contains many important principles and proposals, the most compelling products of this conference are the examples of new thinking that can lead to models for future action,” she said. “It should be said of Rio that people left here thinking, as the late Steve Jobs put it, not just big, but different.”

“This process has been exceedingly ill-prepared,” said de Boer, a special global adviser on climate change and sustainability for the accounting firm KPMG. De Boer praised the “explosion” of new business commitments unveiled in Rio but added, “although I think all the individual initiatives by companies and partnerships are interesting, they don’t deliver the scale that is necessary to address the global challenges we face on sustainability.”

That challenge was underscored by analysis released Wednesday predicting that the number of undernourished women and young children in the developing world will increase from one in seven to one in five because of the impact of climate change on food production

Julio Frenk, dean of the Harvard School of Public Health and one of the authors of the analysis, said in addition to cutting greenhouse gas emissions, governments should adopt programs like ones in Mexico that promote long-term agricultural contracts.

Frenk said collective action on problems such as food security and climate change still need to be brokered at U.N. summits, as flawed as the process may be.

“It’s hard to make any progress,” he said. “But I don’t think we have any choice.”