With the Rio environment conference only five months away, a just-released summit draft calls for "sustainable development goals" toward a green economy but critics slam it as too vague.

Scheduled 20 years after the 1992 Earth Summit in Rio de Janeiro, Rio+20 will be held next June 20-22 to discuss a green economic model that would take into account the environment, promote better social development and eradicate poverty.

It is to take up a broad range of issues on the health of the planet including growth, food security, access to water, lifestyles, energy, biodiversity and climate.

The first official draft of the conference was released last week but critics said it amounted to a mere declaration of principles on the way forward.

Drafted with input from more than 600 contributors, the text recognizes "the limitations of GDP as a measure of well-being" and agrees "to further develop and strengthen indicators complementing GDP that integrate economic, social and environmental dimensions in a balanced manner."

It is to be further refined in the next few months before a final version can be put to the conference.

One of the key proposals involves defining "sustainable development goals" that commit countries to meeting targets in the areas of food security, access to water, green jobs and even "sustainable production and consumption models."

These goals would complement the poverty-reduction Millenium Development Goals set by 192 countries in 2000.

According to the United Nations Environment Program (UNEP), the financial crisis and the depletion of natural resources have fueled "a general disillusionment with the dominant economic model."

UNEP called for an alternative model.

"RIO+20 is a great opportunity to begin thinking and measuring our economy differently," said Roberto Smeraldi, head of Friends of the Earth Brazil, a global network striving for a healthier and more just world.

"The text I think is weak as a final outcome. It is simply a restatement of a lot of principles that governments have committed to already in a number of occasions," Jacob Werksman, a program director at the US World Resources Institute, a global environmental think tank.

And the World Wide Fund for Nature (WWF) said the first draft of the summit document was a step in the right direction but was not ambitious enough.

It called for stronger commitments by world leaders at the conference.

Twenty years ago, more than 100 world leaders attended the Rio conference. But given the current economic crisis, it is unclear how many will show up at next June's summit here.

"We want the conference to be a success. This will require a big turnout at the level of head of state and a strong outcome leading to a landmark political document with concrete actions," said Giancarlo Summa, head of the UN office in Brazil.