Berlin, 25 April 2016. "Urban growth is so immense that it must urgently be channelled in new directions," said WBGU Co-Chair Dirk Messner, Director of the German Development Institute. If more and more new settlements were to be built with cement and steel in the cities of the developing countries and emerging economies, the energy-intensive production of this building material alone could release such huge quantities of greenhouse gases by 2050 that the world's emissions budget of the 1.5°C target would already be virtually exhausted. Yet there are alternatives, e.g. building with wood or other natural materials. "Without decisive political action and international cooperation, humanity's natural life-support systems would be jeopardized by the demand for resources and the CO2 emissions of urban construction," said Messner.
Striving for sustainability in major cities and slums
The living conditions of city dwellers are also an issue here. There are already more than 850 million people today living in inadequate housing conditions. In sub-Saharan Africa, about two thirds of the urban population live in slums, in Asia around a third. Urbanization pressure is especially strong in Asia and Africa, where 90 percent of the global urban population growth is expected to take place. The current refugee movements show how difficult it is even for prosperous countries to cope with a rapid influx of people into their cities. By 2050, the number of people living in inadequate housing could increase by 1?to 2 billion. "This is why the living conditions of people living in extreme poverty in particular must take centre stage in urban development," said Messner. It is this fundamental change of perspective for the new urban agenda that the WBGU aims to initiate at the forthcoming Habitat III conference.
"A city like Hong Kong with its extreme densification is only viable because it sucks in oil, metals and food from the surrounding area and the whole world, digests it, and disposes of residues such as waste, effluent, exhaust gases into the surrounding countryside," explained Hans Joachim Schellnhuber, WBGU Co-Chair and Director of the Potsdam Institute for Climate Impact Research. "The distributed nature of renewable-energy generation, the circular economy and even the digital economy makes disaggregation possible – and to some extent even requires it. Polycentric integration in regions such as the German Ruhr area, which is currently re-inventing itself, or the San Francisco Bay Area can be models for the urbanity of the future."
Create the global conditions needed for sustainable urban societies
In contrast to the great importance of urbanization for the transformation towards sustainability, the corresponding international institutions are only weakly positioned.
In order to intensify the global debate on urbanization and transformation, the G20 should take up the subject on a permanent basis. Germany's federal government has a key role to play here, since it will be assuming the G20 Presidency in 2017. It should put the topic on the agenda.
The United Nations Human Settlements Programme (UN-Habitat) should be reformed and strengthened, so that its influence and efficacy are at least on a par with such programmes as UNEP.
Regular scientific progress reports would help promote an awareness of urbanization among the international community and clarify the actions that are needed for the transformation towards sustainability. There could be a committee similar to the Intergovernmental Panel on Climate Change (IPCC) that could conduct an integrated assessment of the scientific status quo on global urbanization dynamics.
Selected core recommendations for urban transformation fields
Climate and resources
Cities and international politics