The upcoming Rio summit on sustainable development must yield a new model to tackle the planet's economic, environmental and ethical crises, according to Brazilian Environment Minister Izabella Teixeira.

The so-called Rio+20 gathering "is a an exceptional opportunity in a world in which people are searching for new ideas and new processes... to implement a new development paradigm," she said in an interview with AFP in Porto Alegre Thursday.

"The economic, ethical, cultural and environmental crisis which the planet is facing is a clear indication of the urgency of the present," she added. "We cannot talk of sustainability if we continue having poverty, inequality, unemployment, if we don't have a new vision for environmental assets."

The Rio+20 summit scheduled for June 20-22, the fourth major summit on sustainable development since 1972, is to take up a broad range of issues on the health of the world, including growth, food security, access to water, lifestyles, energy, biodiversity and climate.

Teixeira said the green economic model to be discussed in Rio must "offer social inclusion, creation of decent jobs, sustainable use of natural resources and technological innovation."

And she stressed the need for high-level representation at the UN summit on sustainable development, comparable to that at the Rio Earth Summit, which drew more than 100 heads of state or government 20 years ago.

"The presence of heads of state is important as is the presence of civil society and the private sector" to reach full agreement, the minister said.

"Twenty years ago, the focus was on the future. Now we have the urgency of the present. In 1992, there was no crisis, the paradigm was that neoliberalism had a solution for everything. Now we have the economic crisis," she added.

The first official draft of the June conference was released two weeks ago but critics said it amounted to a mere declaration of principles on the way forward.

It recognizes the limitations of gross domestic product 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."

One of its 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 Millennium Development Goals set by 192 countries in 2000.

Teixeira said Brazil's objective was to secure a "broad and solid" agreement at the conference.

She was in Porto Alegre to attend the World Social Forum (WSF), an alliance of social movements opposed to the World Economic Forum, the annual gathering of the world's economic and political elites being held at the same time in the Swiss resort of Davos.

Under the slogan "Capitalist Crisis, Social and Environmental Justice," the forum aims to lay the groundwork for a peoples' summit of social movements to be held in parallel to next June's Rio conference on sustainable development.

Thursday, Brazilian President Dilma Rousseff urged activists at the forum to come up with fresh ideas to help solve the world's most pressing problems.

Fresh ideas were "absolutely necessary" to help the world face the global economic crisis, she said, as she decried the negative effects of the crisis in the developed nations, warning it put "democracy itself" at risk.

WSF militants are sharply critical of the "green economy" concept which they view as "mercantilization" of natural resources and called for real change outside the capitalist that would take into account the welfare of people and the planet.