Maurice Strong and Felix Dodds, BBC Green Room 27 Apr 10;
Following the near collapse of the UN climate negotiations in December and the seeming paralysis of the Convention on International Trade in Endangered Species (CITES) in March, the whole idea of solving the world's environmental problems through multilateral negotiations seems to be in crisis. But, argue Maurice Strong and Felix Dodds, another recent development holds out the promise of reversing the trend.
In two years' time, Rio de Janeiro will host another Earth Summit - 20 years after the first.
The idea was proposed in 2007 by Brazil's President Lula da Silva at the UN General Assembly.
It was clear to President Lula and to a growing number of others that the world has changed enormously since 1992, when the world agreed to Agenda 21 - the blueprint for creating a sustainable way of life in the 21st Century.
Rio 2012 could provide much-needed new momentum to international co-operation, not only on environment and sustainable development, but also on the problems that underpin the global financial crisis.
Broken promises
Most of the problems the world now faces have been on the international agenda for decades, some going back as far the Stockholm environmental conference in 1972.
They have now reached more acute, crisis proportions - not as a result of the lack of proclaimed government commitments to action, but to their dismal performance in implementing their agreements.
Indeed, if governments had implemented the many conventions, treaties and declarations they have negotiated from Stockholm to Rio to Kyoto to Johannesburg, we would be well along the road to sustainability.
Governments have done little to carry out their commitments, particularly as to helping finance developing countries' movement towards sustainability.
This failure has only added to the anger of most developing countries at the continued broken promises, and has undermined their ability to make commitments of their own.
As a result, we now face challenges on a number of fronts:
* Human societies are living beyond the carrying capacity of the planet
* Climate change has emerged as an out-of-control driver of many of the world's environmental and economic crises
* The still-prevailing, consumption-based economic model is not only failing to deliver progress to enormous numbers of the world's population, but is seriously threatening the economic stability of all nations, and compromising the prospect for any of us to live on this planet
* There is now an increasing link between environment and security
* Governments have still not given the UN the mandate, the resources or the institutional capacities required to monitor and enforce international agreements.
All of these issues can be positively influenced by Earth Summit 2012.
But addressing them successfully will require an ambitious and creative agenda.
The UN General Assembly resolution last year which endorsed the summit, produced just that - including these areas of focus:
1. The green economy and poverty alleviation
The current economic model, which has brought unprecedented prosperity to the more developed countries, has only deepened the disparity between them and most developing countries.
Its excesses now threaten the stability of the entire global financial system as well.
The past 30 years have been characterised by irresponsible capitalism, pursuing limitless economic growth at the expense of both society and environment, channelling more and more money into fewer hands, with little or no regard for the natural resource base upon which such wealth is built.
The principal goal of our economy should be to improve the lives of all the world's people and to free them from want and ignorance - without compromising the planet itself.
An economy that integrates sustainable development principles with responsible capitalism can produce enough wealth to meet the needs of people in all nations, equitably and sustainably.
Energy use based on fossil fuels is at the heart of the dilemma, and is the principal source of climate change which threatens the future of all.
Earth Summit 2012 can clearly draw a roadmap to set the world on the path to a new "green" economy that is sustainable, equitable and accessible to all, including the urgent transition to renewable energy.
2. Emerging issues
Environmental and security issues are becoming increasingly intertwined.
The "environment-security/insecurity nexus" covers such overlapping issues as climate, energy, ecosystem destruction, food, water, health and environmental refugees.
At the Copenhagen climate summit, Bangladesh's Finance Minister Abul Maal Abdul Muhith said he expected 20 million environmental refugees to be fleeing his country by 2050, and warned that developed countries would have to accommodate many of them. Are those countries ready?
Earth Summit 2012 can develop a new blueprint to address the environmental and security challenges, defining positive and encouraging ways in which people can work together in addressing them.
3. Sustainable development governance
The present global institutions are inadequate to deal with the Earth's major challenges.
As most of the necessary changes are economic in nature, primary responsibility for decision making cannot be made by environmental ministries. They will continue to be vested in the ministries' of finance, development and trade.
To ensure that these decisions have the required environmental input, it is essential that environmental ministries and agencies have a place at the table and the capacities to ensure that the economic decisions will produce the necessary transition to sustainability.
Earth Summit 2012 should agree on strengthening and upgrading the United Nations Environment Programme (Unep), which should be the most influential champion of the global environment.
Climate changing
What else should we expect from Earth Summit 2012?
Climate change is the biggest single challenge humans have ever faced. It is the greatest security risk we have ever faced; and as a global phenomenon, we face it together.
Earth Summit 2012 can provide a high-profile forum to complete and sign the comprehensive climate change agreement that must emerge from the wreckage of Copenhagen.
What Copenhagen has shown us is that for an effective summit, we need to follow the Rio model of establishing a separate secretariat and secretary-general for the conference.
This would have the aim and mandate to involve and engage the capacities of the entire UN system, ministers, heads of governments, as well as all key stakeholders.
The number of stakeholders across the field has grown hugely in the years since Rio 1992. The new summit can provide an active demonstration of a participatory democratic model, which brings together all those who can contribute to implementation of the decisions taken.
Common future?
Since 1992, awareness of the Earth's environmental challenges has become universal.
What is lacking is the will of governments to act.
Supported, indeed driven, by an aware and actively committed public, governments must and can act decisively.
Earth Summit 2012 needs to utilise communications media assertively and creatively - to engage the global public in a global conversation on how we are able to live on this "one planet" together.
Earth Summit 2012 presents a unique platform for negotiating the co-operation needed to achieve a new deal between North and South, between rich and poor and between present and future generations. A co-operation that is critical to the future of all people on the planet; and a co-operation that we must achieve.
Maurice Strong was secretary general of the first UN environment conference, in Stockholm in 1972, and of the 1992 Rio Earth Summit
Felix Dodds is executive director of Stakeholder Forum
The Green Room is a series of opinion articles on environmental issues running weekly on the BBC News website
