What does the future hold for cities, and how can cities steer the world to a bountiful future? Greg Clark is an urbanist, author, global advisor, chairman and non-executive director. He has advised more than 300 cities, 50 national governments, and bodies such as the OECD, Brookings Institution, the World Bank and the Urban Land Institute on strategies for city development and investment.

Greg Clark will moderate the upcoming Brussels Urban Summit, from 12-15 June, which is co-organised by Eurocities. In the interview below, we caught up with this urban expert to understand the role of cities in local, European and global change.

Does it really make sense to think about a level of government so small and limited as the city, as a place where global challenges can be dealt with?

Yes it does. Here are three big reasons why: First,  the world and the human race is on a dramatic path towards urbanisation. It’s happening as a seamless tempo, a backdrop to our lives.

The important years to remember are 1980 and 2080, a 100-year period which we’re approaching the middle of. In 1980, 2.3 billion people lived in cities, about 40% of the global population. By 2080, 9.3 billion people will be living in cities, about 80% of the world’s population. A doubling of the percentage and a quadrupling of the number of people living in cities. And if you take cities of 1 million or more over that period, we’re going from about 275 cities to 1600 cities, which is a multiplication by six.

The pandemic has not arrested this. We’re on a path to about 10 billion people living in about 10,000 cities by the end of this century.

The consequence of this is that all of the challenges that the world faces; climate change, economic productivity, inequality and poverty, segregation and spatial justice, the intergenerational challenges, the scarcity of materials, the future of food and water, and housing: all of these issues are increasingly becoming urbanised problems. That means that to solve any of the problems that the world faces, we need a focus on cities. That’s where those issues are concentrated.

We can choose to try to address those issues without city governments being involved, but it makes no sense to do that.

Second, nearly all of the issues that the world needs to address have a spatial or a place-based dimension. It’s easy to think that climate change is just about switching our energy sources.  But in order to make that switch, we also need an urban transition. The net zero path equals the energy switch plus the urban transition.

In other words, it’s the reequipping of our transport systems, our buildings, the reorientation of our consumption habits, our mobility choices, and in particular, the way that we use land. Because if we switch energy but we don’t switch the systems that use energy, we end up with a mismatch between the new energy sources that we have and the old systems that need to use them. So, in order to achieve a net zero path, we need to have that urban transition.

Now that urban transition requires investment in the retrofitting of buildings and the reorientation of transport systems. But there’s much more in there that requires city governments to be very actively involved, because city governments are often the planning authorities for land and buildings, they’re often the authorities who have the statutory responsibility for housing supply, and many are also transport authorities.

So without city governments directly involved, there’s no hope of achieving the urban transition in either the built environment or the transport systems, which between them are 70% of all of the carbon emissions.

Third, city governments are close to both local people and to businesses at the local level. The path towards tackling inequality, desegregation, productivity gaps, climate, requires a local convener of multiple stakeholders, to get them to work together and to motivate change by pushing bold policies, innovations, and experiments that will demonstrate to those stakeholders how change can be achieved in a way that is just and fair, and provides opportunities.

For example, it was only when the city of Oslo said cars may not enter the centre of the city that we began to see accelerated innovation occur in other forms of transport. It was only when the city of Barcelona said we are going to create more green space within the city that we end up with a ‘super blocks’ policy that reclaims road space to improve greenery and tackle air quality challenges. It was only when the city of Amsterdam says we want to have a policy of encouraging our residents to really get to know their region and to visit it properly, that they were able to restrict and deter anti-social behaviour by visitors within the city. City governments play a key role in nudging behaviour change by taking experiments or developing innovative policies. They bring stakeholders to work together.

This convener and innovator role of city governments are tasks are tiers of governments are not able to do because state and regional governments, national and federal governments, are all locked in to the silos of sectoral ministries. It’s only cities and city governments that are really able to think about the integration of these different things within places. So that’s why it’s important to have cities at the table.

Will city growth paradoxically mean that cities become less agile, less able to confront global challenges?

As populations grow and urbanise, city councils and their neighbouring municipalities and counties become increasingly inter-dependent. It is important to continuously improve governance, and that sometimes means adjusting the boundaries of urban councils. Either the city increases its boundary, or we develop two-tier urban governance where we’ve got both local and metropolitan authorities working together. It’s important to do that because there are otherwise multiple unhelpful consequences if we have fragmented local government.

If you have effectively a population base of 5 million people and they’re all in the same housing market and labour market, but they’re being served by different municipalities, the risk of policy conflict and coordination failure is very great. So it’s important that they’re able to work together in a coherent way.

You can do that by having a single big city government that covers a very large area, for example in Australia with the City of Brisbane, which has the biggest local government area of any city in the southern hemisphere, or you can have the model in Stuttgart, which has brought together about 40 polities into one coherent group. Most recently in Italian cities you’ve seen ideas to create a metropolitan area that is well organised. Most of the big cities in Europe have a strong city government, but they also have some kind of metropolitan platform.

Does size prevent innovation? I think the answer here is no. As long as the cities focus on the distinctive challenges that exist in different parts of the city and they apply an innovative mindset to each of them. So, it’s quite possible that as a city grows in size, then the city government or the metropolitan government grows in competencies and in resources. It’s then more able to look at the specific challenges of particular places. Generally speaking, Europe has done pretty well in this regard, and Europe’s secret weapon in reinventing our cities after the pandemic is the comparatively high social capital that has enabled our cities to be agile. In general Europe’s citizens trust city leaders more than in other regions.

As cities grow, will we see them become more empowered on the global stage?

In general, city governments all over the world do not have the powers that they need to tackle the challenges that the world faces, even if those challenges are increasingly concentrated in cities. Local governments are commonly locked into a pattern of constitutional authority that is 50 to 75 years out of date. So in Latin America, for example, many local governments are not legally allowed to do things that have a cross-border dimension, even though they need to collaborate with their neighbours. They are restricted to actions directly and solely within their municipal boundaries.

In Australia, local governments are so poorly underfunded that they resist new housing growth within their area because it doesn’t come with the investment needed to make places liveable, and the local governments don’t retain the additional revenues raised from an increased population.

In India, where 46 municipalities are in the metropolitan area of Mumbai, the powers of the local governments are weak relative to the powers of the state, and therefore they tend to oppose development and investment.

So we’ve got a historic pattern of national and state and regional governments being slow to  equip local governments with the tools, competencies, revenues, and the powers that they need in order to do what we need them to do. There’s a gap, a long-term historic deficit in the powers that city governments have.

This creates a sense of doubt: Why would you involve the city government’s when they are not very powerful institutions? We have a system of underpowered cities. However, at the same time, we have many examples of a small number of highly empowered cities: Vienna, Copenhagen, Amsterdam, Hamburg, Berlin, Singapore, Hong Kong, New York. These are all examples of cities that have more power than the average, and they’re often the cities that we can see are the ones that innovate. All cities can innovate, but the ones that can innovate most are the ones with greater institutional power.

It would be impossible for Vienna to have a €1.00 a day public transport system and the most affordable housing system in the world if it wasn’t for the fact that the city, which is also a state in the Austrian federal system, created the Vienna Holdings company about 65 years ago to be, in a sense, the ‘sovereign wealth fund’ for the city. So, although, in general, cities are under powered, we have lots of examples of cities that are empowered, and we see how much more they can do.

The gap is visible, but the quality of what is achieved in the cities that are highly empowered is so attractive that we know that the empowerment of cities is important. Singapore is the single most improved city in the world in the last 60 years. Why is it possible for Singapore to go from being a poor post-colonial island state to being one of the great innovative cities of our time? It’s because they’ve got a very powerful governance system – the city is also a nation state. So, we are tantalised by the opportunity for more cities to have the same level of power as a Singapore, Vienna, Hamburg, Berlin, or Copenhagen. We want all cities to be able to do that because that’s the way to equip us to address these urbanising global challenges.

But we would also be wrong to say that it’s only hard power that matters. Hard power is the legal competencies for city governments to be in charge of things that really matter: land use planning, infrastructure, utilities, investment, transport and housing systems. In some countries city governments have control of education, housing, social services, leisure facilities. It really helps when city governments have tax raising powers, then they also have the power to incentivise, using the tax system by pricing different kinds of behaviour differently.

If they have the power to raise taxes, they generally have the power to borrow, to create larger capital expenditure budgets and to invest in systems. So hard power matters. But soft power is also important.

By global standards, European cities have a secret weapon that very few other cities around the world have, and you could call it social capital. Social capital or trust, that’s the ability to form trusting relationships, both with local people and with other stakeholders, to convene, to build alliances, to create coalitions that are able to promote innovation and change.

So even with cities being underpowered in terms of the hard power, they can generate soft power that enables good things to happen. But what we need is a situation where the responsible exercise of soft power leads more frequently to greater hard power, and the achievement of more responsible hard power contributes to the soft power.

Hard power and soft power are not alternatives, they’re mutually reinforcing. Cities that win the most new hard power through reforms are often the ones that have exercised the best soft power in the lead up to it. The empowerment of cities is a really critical agenda going forward if we are to tackle those global challenges. Europe is not a ‘worst case’ in all of this, but there’s been much faster focus on empowering cities in Asia Pacific. In the Americas, progress is slower because the state and national governments resist municipal empowerment. But that may be finally changing in Latin America.

How important is the dimension of urban collaboration?

Two things about this really matter. The first thing is that as the century of the city unfolds, we will increasingly not so much look at the individual performance of single cities, but we will be looking instead at regional networks of cities and towns in a single territorial space. As we’ve seen in China, the Association of Southeast Asian Nations, and North America, regional groupings of cities will matter more. We’ll focus much more on the cities of middle Europe, the Nordics or the cities of the Mediterranean rim. We’ll focus on cities that are within key triangles, or on certain corridors. Just as we have got used to thinking of Amsterdam, Rotterdam, The Hague, and Utrecht, and increasingly Eindhoven, as a network of inter-dependent cities, we will start to see many more groups sharing a common housing system and labour market, underpinned by physical and digital connections.

So, regional connectivity is key, and then there is the wider European and global connections. We should think of city networks as an innovation ecosystem. The whole idea of an ecosystem is that you bring together complementary biological elements so that when they interact with each other, they create new forms of life, ideas, innovations and opportunities for sustainable growth.

So the networking of cities should operate as an innovation ecosystem to rapidly spread ideas that work in one context, to see how they can be adapted, adopted, and translated, to inspire other local innovations.

This also creates an opportunity for cities to use both their soft power and their existing hard power to make a strong case on a European level for greater competence. So, the networking is an innovation ecosystem, and it’s also part of the power of cities.

So we may see a world run by cities?

I don’t think that we should pretend that we’re living in a world which is run by cities. I think the world is run within cities, by all of the actors that are there. City governments are not yet running the world, and we have to accept that this century of cities is also happening within the era of the nation state, which is a powerful organisational tool.

Our world is organised around 197 nation states, and they’re not about to dissolve themselves anytime soon. This idea that mayor’s can rule the world, I think, is fanciful. But the city governments can acquire more power and have better relationships with national governments, so that the national governments will eventually see that it’s not possible to achieve national policies with disempowered cities.

It’s only possible to achieve those policies with empowered cities. That is the goal that we should have. One of the purposes of European and global city networking events like the Brussels Urban Summit is to help drive this forward. If the world’s problems are increasingly urbanised, we will need powerful city governments if national states are to be effective. It’s a positive sum and not a zero sum.