Nearly 20 years after the 1992 Earth Summit, the world is once again on the road to Rio - the site of the June 2012 UN Conference on Sustainable Development. Much has changed in the past two decades, geopolitically and environmentally. Hundreds of millions of people in Asia, Latin America - and, increasingly, in Africa - have risen from poverty. Yet, evidence is also accumulating of profound and potentially irreversible changes in the ability of the planet to sustain our progress.
Rapid economic growth has come with costs that traditionally rarely feature in national accounting. These range from atmospheric and water pollution to degraded fisheries and forests, all of which impact prosperity and human well-being. The theme of World Environment Day this year, "Forests: Nature at Your Service", emphasizes the multi-trillion dollar value of these and other ecosystems to society - especially the poor.
Despite growing global awareness of the dangers of environmental decline - including climate change, biodiversity loss and desertification - progress since the Earth Summit has been too slow. We will not build a just and equitable world unless we give equal weight to all three pillars of sustainable development - social, economic and environmental. To sustainably reduce poverty, guarantee food and nutrition security and provide decent employment for growing populations, we must make the most intelligent use of our natural capital.
India, the global host of World Environment Day in 2011, is among a growing number of countries working to address the pressures of ecological change. It is also helping to pioneer a better assessment of the economic value of nature-based services, with the assistance of the United Nations Environment Programme and the World Bank. India's Rural Employment Act and the country's encouragement of renewable energy are significant examples of how to scale up green growth and accelerate the transition to a green economy.
No single day can transform development onto a sustainable path. But on the road to Rio +20, this year's World Environment Day can send a message that those with influence in government and the private sector can - and must - take the necessary steps that will fulfill the promise of the Earth Summit. The global public is watching, and expects nothing less.