25 April 2018

Utrecht University’s Professor Maarten Hajer is one of the lead authors

UN report about the future of the city: 'New calculation made'

The world is urbanising at a rapid rate, with the global urban population set to increase by approximately 2.4 billion people in the next 30 years. The question of how to provide these people with sustainable and liveable housing is currently being considered by a United Nations special panel. Maarten Hajer, Professor in Urban Futures at Utrecht University, was one of the lead authors of a report that is due to be presented this week.

Climate measures – quite rightly – often focus on reducing CO2 emissions. However, at the end of this week, the United Nations will consider a lesser known, but no less urgent, climate theme: the sustainable city and how to design it. The following illustrates the importance of the subject: in 2011-2013, China used more cement than the United States had done in the whole of the 20th century. Despite this fact, the policy needed to ensure the appropriate use of the huge quantity of resources required is currently still inadequate.

It's a misconception to think that a more densely populated city is less liveable too
Maarten Hajer
Professor Urban Futures

 ‘Almost half of the urban infrastructure needed globally by 2050 is still to be built”, says Maarten Hajer. ‘It's very important that we do this differently and make sure that the new infrastructure is sustainable, inclusive and pleasant. We must intervene now to avoid a complete disaster in the future.’


Hajer is a member of the International Resource Panel launched by UN Environment. This panel is due to present a report – entitled The Weight of Cities – at the Resilient Cities Forum in Bonn this week. Hajer is one of the two co-chairs of the working group and one of the lead authors of the document. ‘In the report, we calculate the resources necessary if we carry on as we have done in the past. This calculation has never been attempted before. The report also makes a number of recommendations about how to realise sustainable urban planning, making cities enjoyable and healthy places in which to live.’

The report uses the DMC (domestic material consumption) unit of measurement, which reveals the number of tons of resources (sand, gravel, steel, ore, coal and wood, for example) used per resident per year. Sustainable resource use lies between just 6 and 8 tons a year. However, if no changes are made, the authors estimate that resource use will be between 8 and 17 tons per person per year in 2050, which is too high.


The recommendations made on how to reduce resource use are diverse and ambitious. For example, a city must be designed for people, not cars. To achieve this, 30 percent of the developed area in a city must have a minimum street length of 18 kilometres per square kilometre, with between 80 and 100 crossroads per square kilometre. Hajer: ‘We seem to be forgetting what we already know about what makes cities attractive. We will need to plan much better in the future – both here in the Netherlands and elsewhere. For example, a metre of train tracks, motorway and cable could be saved for every metre that people live closer to the places where they work. It's a misconception to think that a more densely populated city is less liveable too. However, you do need to design a city cleverly, including amenities like parks and public gardens.’