The first challenge is to define the city, where does it start and where does it end. This not only means spatially but also temporally. Will the city expect to continue growing with respect to infrastructure and buildings or does it expect to reach a full grown state in the future? As an example, Amsterdam and my home town Utrecht are considered separate cities, continuously growing. But what happens once they reach each others borders? Is such a continuous urban sprawl wanted? Maybe it’s smart to start planning ahead and to define the Netherlands as a very green megacity? Once we have defined the city boundary we can start investigating the city as a system. How does it function? What are the inputs and outputs. For this the city needs to gather data, lots of it! Then comes the question who owns the data, where is it stored and how will it become available. Will it be static or is there a possibility to dynamically alter and update it like Wikipedia. Also privacy issues need to be solved. Once there is good open data available it becomes possible to start thinking about holistically redesigning the city. How can the city for example best handle its water flows? What if, for example, the water chain was managed by one organization, as is the case with Waternet in Amsterdam? Directing this redesign a shared vision is needed where the city wants to be in the future, for example in 2050. Given the global problems of climate change and resource exhaustion when does the city want to become fully circular or energy neutral? How will the city mitigate and adapt to climate change? Will it want to become a carbon neutral city or even carbon negative, functioning like a forest? In the meantime it should not forget about its citizens. The city needs actively participating and educated citizens. The gathered data therefore needs to be accessible to both the city government and its citizens, and the city government needs to facilitate bottom up initiatives. There are already many solutions available around the world and the city and its citizens can learn from these and apply them locally. A big challenge however is the increasing income inequality between citizens, how will the city solve this problem? Will solar panels be available to everyone or only to the rich? In this respect it is important to strengthen the local economy of the city, possibly aided by a local currency. This would incentify citizens to use local food, products and services. An example of a local currency is the Utrecht Euro (4) in the Netherlands. Cities should also not neglect their dependency of the neighboring rural area. Will the rural areas for example be compensated when filled up by solar farms and wind turbines to solve the energy needs of the city? In the Netherlands this will need to be solved using Regional Energy Strategies. Does the city also want to become self-sufficient with respect to food? Will the rural area surrounding the city be sufficient or will the city need large scale urban farms to feed its citizens? And what about meat consumption? Will the city be flexible when a new technology like clean meat has proven itself?
So as you can see there are many challenges for modern cities, but perhaps the biggest challenge is how to start working on all these complex interconnected challenges. How not to collectively feel overwhelmed and bury our heads in the sand and behave as if nothing is going on. Business as usual. This is the biggest challenge.