A fundamental overhaul of global environmental governance is needed now to avoid dangerous "tipping points" in the Earth system, 32 social scientists and researchers from around the world conclude in a new paper published Friday in the journal "Science."

These conclusions are reinforced by a new 40-year-outlook report just issued by the Organization for Economic Cooperation and Development, OECD, whose 34 members include the world's largest economies.

Sharp increases in natural disasters, food and water security problems, biodiversity loss and climate change are just part of the evidence that humanity may be crossing planetary boundaries and approaching points of no return, called tipping points, write 32 leading governance experts from the Earth System Governance research alliance in their "Science" article.

To reduce the risk of global environmental disaster, they say a "constitutional moment" in world politics is required, comparable in scale and importance to the reform of international governance that followed World War II.

Lead author Frank Biermann, of Free University Amsterdam and Lund University, Sweden, said, "Societies must change course to steer away from critical tipping points in the Earth system that could lead to rapid and irreversible change. Incremental change is no longer sufficient to bring about societal change at the level and with the speed needed to stop Earth system transformation."

"Structural change in global governance is needed, both inside and outside the UN system and involving both public and private actors," said Biermann, who also is chair of the scientific steering committee of the Earth System Governance Project.

The paper is a key contribution of the science community to the 2012 United Nations Conference on Sustainable Development, Rio+20 slated from June 20-22 in Rio de Janeiro, Brazil. This gathering follows up on the Earth Summit in Rio in 1992.

"Science assessments indicate that human activities are moving several of Earth's sub-systems outside the range of natural variability typical for the previous 500,000 years," wrote the authors in the opening of their article, "Navigating the Anthropocene: Improving Earth System Governance."

The research group argues for the creation of a UN Sustainable Development Council to better integrate sustainable development concerns across the UN system, with a strong role for the 20 largest economies, the G20. They supports upgrading the UN Environment Programme to a full-fledged UN agency, a status that would give it greater authority, more secure funding, and facilitate the creation and enforcement of international regulations and standards.

Stronger consultative rights for representatives of civil society in global governance are needed, based on mechanisms that balance differences in influence and resources among civil society representatives, these experts recommend.

To improve the speed of decision-making in international negotiations, the authors called for stronger reliance on qualified majority voting.

"There has to be a change in international negotiating procedures from the current situation, in which no action can be taken unless consensus is reached among all participating governments," said contributing author Kenneth Abbott, a professor of international relations in Arizona State University's Sandra Day O'Connor College of Law.

The authors also called for governments "to close remaining regulatory gaps at the global level," including the treatment of emerging technologies.

"A great deal of attention has been given to issues such as climate change, yet nanotechnology and other emerging technologies, which may bring significant benefits, also carry potential risks for sustainable development," warned Abbott.

The research group also argues for increased financial support for poorer nations, writing, "More substantial financial resources could be made available through novel financial mechanisms, such as global emissions markets or air transportation levies for sustainability purposes."

"Working to make the world economy more green and to create an effective institutional framework for sustainable development will be the two main focal points at this summer's United Nations Conference on Sustainable Development in Rio de Janeiro, “Abbott said. " This article was written to bring urgency to those discussions and to outline specific building blocks for a more effective and sustainable Earth system governance system."

These conclusions are supported by the "OECD Environmental Outlook to 2050: The Consequences of Inaction" presents the latest projections of socio-economic trends over the next four decades, and their implications for four key areas of concern: climate change, biodiversity, water and the health impacts of environmental pollution.

Despite the recent recession, the global economy is projected to nearly quadruple to 2050. Rising living standards will be accompanied by ever growing demands for energy, food and natural resources - and more pollution.

"Greener sources of growth can help governments today as they tackle these pressing challenges. Greening agriculture, water and energy supply and manufacturing will be critical by 2050 to meet the needs of over nine billion people," said OECD Secretary-General Angel Gurria.

"The costs of inaction could be colossal, both in economic and human terms," the OECD warned.

Without new policies, the OECD report warns:

• World energy demand in 2050 will be 80 percent higher, with most of the growth to come from emerging economies and still 85 percent reliant on fossil fuel-based energy. This could lead to a 50 percent increase in greenhouse gas emissions globally and worsening air pollution. Energy demand for North America is projected to increase about +15 percent, for OECD Europe +28 percent, for Japan +2.5, and for Mexico +112 percent.

• Urban air pollution is set to become the top environmental cause of mortality worldwide by 2050, ahead of dirty water and lack of sanitation. The number of premature deaths from exposure to particulate air pollutants leading to respiratory failure could double from current levels to 3.6 million every year globally, with most occurring in China and India. Because of their ageing and urbanized populations, OECD countries are likely to have a high rate of premature death from ground-level ozone in 2050, second only to India.

• On land, global biodiversity is projected to decline by a further 10 percent, with significant losses in Asia, Europe and Southern Africa. Areas of mature forests are projected to shrink by 13 percent. About one-third of biodiversity in rivers and lakes worldwide has already been lost, and further losses are projected to 2050.

• Global water demand will increase by some 55 percent, due to growing demand from manufacturing (+400 percent), thermal power plants (+140 percent) and domestic use (+130 percent). These competing demands will put water use by farmers at risk. The OECD report projects that 2.3 billion more people than today - over 40 percent of the global population - will be living in river basins under severe water stress, especially in North and South Africa, and South and Central Asia.