UN leader Ban Ki-moon is battling to rescue a summit of more than 100 world leaders in Rio de Janeiro in two weeks which he says must guide the world away from a "tragic" end.
The UN Conference on Sustainable Development is taking on the vast challenge of transforming environmental, social and economic policy to cope with a world population past seven billion, exhausting dwindling resources and straining cities to the limit.
Ban and specialist groups have however accused governments of putting national interests before the common good in months of agonising negotiations before the Rio event to mark the 20th anniversary of the Earth summit in the same city.
Rich nations have been hit economic crisis and want austerity. Poor nations complain that past promises to give extra cash and new technology to battle climate change, poverty and epidemics have still not been carried out.
With US President Barack Obama, Britain's Prime Minister David Cameron and Germany's Chancellor Angela Merkel staying away from the so-called Rio+20 summit, the UN secretary general is now furiously lobbying leaders to get an action plan agreed.
"We have to now have a correct vision where we are heading. Whether we are heading toward mutual prosperity, common prosperity, or whether we are going toward very negative tragic consequences for humanity," Ban said Monday in Saudi Arabia.
"The negotiations have been painfully slow," he said in a recent meeting with reporters.
"This planet has limits and we have to do something for coming generations," he added, highlighting the droughts, floods, food shortages and the frantic exploitation of minerals that blights various parts of the world.
Ban says governments should be more flexible. "They should rise above national interests or group interests."
The summit will touch on just about every social and environmental problem facing the world ranging from food security, global health, livable cities to oceans and climate change.
Thousands of pages of proposals for the Rio+20 final agenda, were cut to 200 pages in the first talks last year, only to mushroom back up to 275 under review. It is still an 80-page blockbuster.
Rich and poor nations cannot agree how to define the green economy and set out a plan for its development.
The summit aims to set out new Sustainable Development Goals that would take in the eight Millennium Development Goals on improving health and eliminating poverty but add new targets to protect the environment and the Earth's resources.
For now, there is no accord how many goals there should be and what they should be. The 193 UN members have proposed 26 areas - ranging from health to livable cities and protecting oceans and mountains - for which new goals should be set, according to Ban.
Diplomats say rich nations cannot agree among themselves how to police the new era of sustainable development.
There have been calls for the strengthening of the UN Environment Programme, which is based in Nairobi, to turn it into a super agency. Other nations want a Sustainable Development Council with the same moral authority as the UN's Human Rights Council to name and shame.
"Every indication is that governments are basically set to endorse more of the same. From everything we know from scientists and civil society we need a major course correction. And that's the big gap we are staring in the face," said Antonio Hill, Oxfam's campaign advisor for the summit.
Jeffrey Huffines, UN representative for the World Alliance for Citizen Participation (Civicus), which represented non-government groups in the summit preparations, said "big differences" remain.
Huffines highlighted the "lack of trust" between rich and poor and the absence of top leaders such as Obama.
"Whether or not the heads of state of some of the more powerful countries come, we will go back to our respective countries where we will hold our governments accountable to agreements made in Rio," he said. AFP