Twenty years on from the ringing declaration of intent of the Rio Earth Summit in 1992, the empty conference pavillions of Riocentro Convention Centre - vacated yesterday by the 19,000 delegates to its successor, Rio+20 - now echo to a more depressing sound. A dismal patter of disappointment and frustration has rained down on the efforts of 190 nations to breathe life into the notion of sustainable development:

'Epic failure' were the words of a Greenpeace director. 'Profound disappointment' said a letter from 1,000 NGOs. 'Woefully inadequate' cried the Friends of the Earth. 'Colossal failure of leadership and vision' said the director-general of the WWF.

And it's not just the usual suspects lowering a cloud of doom over a summit dubbed optimistically 'The Future We Want':

'There is no energy here. It's an empty shell' said the head of the United Nations Environment Programme. 'It contributes almost nothing to our struggle to survive as a species,' said a Nicaraguan conference representative. 'Insipid' said the UK's Deputy Prime Minister.

Planet pressing boundaries

The chorus of negativity is all the more worrying when looking at the environmental backdrop to second Earth Summit in Rio - despite the passage of 20 years, the indicators are only flashing red more urgently. CO2 emissions have increased by 36%; the planetary population has swelled by 1.5 more billion people; and 300 million hectares of primary forest have disappeared. The sense of that humanity is pressing against the planet's boundaries has been reinforced repeatedly by scientific study - only this April a report by the UK's Royal Society pressed for an urgent change in direction.

That report emphasized what an earlier UN report had concluded - the need to switch from a dogged pursuit of material economic growth that seems heedless of the wider costs. The fact that primary theme set for the Rio+20 conference - 'the green economy' - did, therefore, hold out some hope that world leaders may finally grasp the urgency of changing the economic tack.

Talks about talks

Sadly, the only outcome from all the talk at Rio+20 about the 'green economy' was to keep talking - about more talks. The final Rio+20 agreement aims to agree, by 2015, a set of 'sustainable development goals', which would define targets for areas such as resource consumption, water use and sustainable food production. Talks about talks would be fine, if this was the first Rio summit, back in 1992. But it might have been hoped that, twenty years later, that real action would be top of the agenda.

This lack of action extends further down the priority list - on proposals for international protection for the world's oceans, to calls to end the $1 trillion bill for fossil fuel subsidies, on measures to act on women's rights to reproductive health - all of these failed to make it into the final agreed text of Rio+20. Absence seems to be the dominant theme.

Roll out the fluff

There were no new funds agreed to address the world's pressing environmental and development problems. There were no new international conventions or accords agreed. There was no action on the need to wean the world from its fossil fuel addiction. There were words - and plenty of them too - but words that seemed devoid of intent.

'283 paragraphs of fluff' was George Monbiot's pointed comment in the Guardian, referring to the final agreed text released yesterday at the close of the summit.

So at what point did 'urgent' become translated into 'anodyne'? That is a little difficult to tell, given that the final text was agreed even before the delegates had arrived - and because of the absence of the press from those initial negotiations, or the conference halls later. But some idea of the changing attitudes among the 'middling income' countries, such as China and the host, Brazil, can be gleaned by remarks made by its finance minister, Guido Mantega:

"The expansion of trade with China can be infinite," he told the Guardian at Rio+20. "China is fast growing and wants to stimulate consumption so they will continue to buy our commodities. There are no limits." For the rising economic powers of China, India and Brazil, the notion of sustainable development is as much a vacuous 'buzz word' as it has long been for the falling economic powers of the West.

Courted by a powerful bloc of countries enjoying their rising material wealth, as well as a weakening bloc of countries desperate to hold onto theirs, no-one seems keen to look for a replacement for the economic goose. All are still in throe to those golden eggs (even if they seem to be being laid less regularly). Instead, world summits such as Rio+20 seem to serve mainly to find ways to paint the capitalist goose fetching shades of green.

So if the Rio+20 summit appears to have lived up to its detractors, and become shrouded in a cloud of bad feeling, where to find the silver lining?

Silver lining outside conference?

The answer may be to look outside of the summit itself. Parallel to the Rio+20 conference scene was an alternative scene - dubbed the People's Summit - attended by some 15,000 people-a-day from a host of grassroots organizations across the globe. Here there were campaigns to oppose the commercialization of water rights by big water companies, to stop oil drilling in the Arctic, and to promote indigenous people's rights.

There was also a willingness to challenge the 'business-as-usual' approach that Rio+20 implicit endorsed. Sonia Guajajara, from the Articulation of Indigenous Peoples of Brazil (APIB), told the IPS at the People's Summit: "Native peoples know perfectly well what sustainable development involves. Our harmonious coexistence with nature is a living portrayal of our way of life, which neither destroys nor degrades."

Perhaps we should stop looking for 'The Future We Want' inside concrete conference pavillions, like RioCentro, but outside of them - and closer to home.