A green economy can improve human well-being and social equity while significantly reducing environmental risks, costs and ecological scarcities. In its simplest expression, a green economy is low-carbon, resource-efficient and socially inclusive. In terms of productivity, a green economy "decouples" economic growth from the rate of natural resource consumption, and thus environmental degradation.

The good news is that this is already happening in parts of the global economy, although not nearly fast enough. Today, 65 countries have embarked on green economy and related strategies. This includes many countries engaged with the Partnership for Action on Green Economy (or PAGE) to shift investment and policies toward clean technologies, resource-efficient infrastructure, well-functioning ecosystems, green skilled labor and good governance.

As an input to virtually every human product or process, energy is a proxy for creating an impact and making progress. In just a few decades, the renewable energy sector has grown almost exponentially and accounted for nearly half of all installed electrical generating capacity in 2014, excluding large hydropower plants. The International Energy Agency estimates that boosting energy efficiency alone could provide not only a 10 percent reduction in global energy demand by 2030, but also save $560 billion.

In all, harnessing existing technologies and appropriate policies to increase resource productivity would liberate $3.7 trillion globally each year that is otherwise wasted. And these currently wasted funds could be invested in substantial health, education and development objectives.

One of the keys to productivity and decoupling environmental damage from GDP is to make prices tell the environmental truth. The International Monetary Fund estimates that the total cost of public subsidy to fossil fuels amounts to more than $5 trillion a year when direct and indirect subsidies are counted.

Getting price signals right, educating consumers and making policies that foster a green economy are not only desirable, they are essential. How well we succeed will determine whether the "Anthropocene" is an age when more than 9 billion people have access to food, energy and security without compromising the vital life support systems of our planet.

The author is UN under-secretary-general and executive director of the UN Environment Programme.

(China Daily 06/06/2015 page5)