DW: What status does the new assembly give environment within the UN context?

Achim Steiner: This is the first reform since UNEP was established in 1972. The United Nations Environment Assembly UNEA has universal membership. That means every country, every observer state will be represented, thereby creating a forum that is far more representative, more authoritative and more legitimate in trying to take the environmental aspects of the broader sustainable development agenda forward.

Previously a rotating governing council from just 58 countries governed UNEP. This marks a strengthening and upgrading, a "coming of age" of environmentalism.

Who will be attending UNEA?

UNEP's headquarters in Nairobi, Kenya, will feel like the environmental capital of the world, with the ministers responsible for the environment from over 160 countries in town. There will also be representatives of the world's judiciary coming, because the whole question of enforcement of environment legislation is becoming ever more central.

We will be presenting a new report on environmental crime, trade in wildlife and related activities. At the same time, representatives from the world of finance, from central banks and capital markets will be there, looking at the issue of the financing of the green economy. So this new UNEA is for all actors who see environment as an increasingly important force in shaping the future of economic policy, development policy, and indeed of international relations.

Sustainable Development Goals and the post-2015 Development Agenda, including sustainable consumption and production, are the focus of the first session. What are the main challenges here?

Today, at the beginning of the 21st century, this is principally about conceiving of a future in which 10 billion people can feed themselves, in which we can provide energy and electricity to 10 billion people without destroying the atmosphere. That has a lot to do with transforming our economies and making the environmental community economically more literate, but at the same time evolving its own understanding that people matter in the context of protecting the environment.

People matter, but at the same time there is a huge frustration that governments are not tackling the challenges of environmental pollution and climate change fast enough?

If you are a scientist or an environmentalist, you have every reason to be frustrated at the pace of progress. But we have seen many things change in the last decades, from cleaning up the environment to bringing a whole energy revolution into place in less than a decade and a half.

Last year, the world invested more money in new renewable energy infrastructure than oil gas and coal together. These are fundamental changes being driven by an environmental awareness, a changing public perception and by an economy that is responding.

At the same time it is quite clear that we are facing an escalation and a scale of environmental change to which most responses at the moment are inadequate. But that doesn't mean they are not gaining momentum or that we are heading towards a doomsday scenario.

Is Europe losing its position as an environment leader?

Europe has evolved into a significant and economically more cohesive region that has also been able to introduce many innovations in environmental and social policies. It has a very strong role in the international community as an innovation center on renewable energy, public health and environmental standards.

At the same time Europe is going through a phase partly caused by the financial crisis, but also by the challenge of its own internal coordination, that has made it more vulnerable to other countries taking on a leadership role in sustainability issues, which Europe occupied in many areas.

So are we looking to China?

The depletion of natural resources, the public health impact of rapid industrialization, the images of air pollution in the cities and of a heavily fossil fuel-based energy economy clearly are not images of a green China. But if you look at the scale and the ambition with which China is investing in a transition towards a green economy, then I think you have to take China very seriously over the coming years and decades.

It is not an accident that China at its last party congress introduced the notion of a move towards an ecological civilization as one of the core ideologies driving the vision of development for this nation of 1.4 billion people. So yes, I think we can look to China in the coming years, certainly as one country in which the sustainable development paradigm is gaining a far more central role in determining economic and social policies.

China and the US gave a boost to the climate debate with recent announcements on emissions caps. Have we arrived at a turning point?

I think if you look at the signals coming from two of the major polarities in the international climate debate, you are seeing a very significant shift in domestic reorientation, which is the foundation for taking a different posture at international levels. Not only their announcements but both countries' recent track record in terms of investments in renewable energy, efficiency, mobility, fuel efficiency all point towards the fact that a significant reorientation of the economy towards low carbon is under way.

Achim Steiner is a German-Brazilian politician specializing in environmental and economic issues. He has been director of the UN Environment Programme since 2006.