Climate change and cities: a prime source of problems, yet key to a solution

Cities are home to half the world’s population and produce around 75% of the world’s GDP and greenhouse gas emissions. By 2050, between 65% and 75% of the world population is projected to be living in cities, with more than 40 million people moving to cities each year. That’s around 3.5 billion people now, rising to 6.5 billion by 2050; a huge and singular event in human history. This places cities at the centre of economic activity affecting how economies grow, how resources are allocated, how innovation takes place, whether innovation is used well or badly and, if badly, how much damage it inflicts on others now and in the future. They can also be very exposed and vulnerable to climate risks such as water shortages, floods and heat stress. The mass congregating of people and rising demand for resources, under poor organisation and governance, make cities prime sources of pollution, congestion and waste.

However, cities are also a key part of the response. They afford multiple opportunities to dramatically reduce carbon emissions while sustaining prosperous standards of living. Indeed, there is no hope of reducing global emissions to safe levels if new and expanding cities are based on a sprawling, resource-intensive model of urban development.

Compact urban growth can create cities that are economically dynamic and healthy. The Global Commission on the Economy and Climate, a partnership led by 28 business leaders and former heads of state, and its flagship New Climate Economy project (NCE), found that compact, connected and coordinated cities are more productive, socially inclusive, resilient, cleaner, quieter and safer. They also have lower greenhouse gas emissions – a good example of the benefits of pursuing economic growth and climate action together.

Cities are all about efficiency. It is why they are there in the first place. Gathering people together near accessible transport nodes (often rivers or sea ports) allowed materials, water and food to be imported and distributed efficiently, while waste and exports were shipped out. But cities afford an even larger, dynamic source of efficiency gains – the spread of ideas.

Economic growth is driven by learning and innovation and the accumulation of ideas, skills and ‘knowledge capital’. Knowledge and innovation allow society to decouple growth from resource use to ensure that we can get more out of the resources we have. Unlike other resources, knowledge capital is weightless and does not deplete. Quite the reverse, knowledge builds on knowledge, making this a “magic resource” subject to unlimited economies of scale.

The intellectual economy is often reliant on investment in physical capital. New equipment enables new ideas and innovation in technologies. For example, investing in computers induces bright ideas about how to use them. Investing in integrated public transport and cycle infrastructure changes people’s modal behaviour and enables new apps to monitor and report real-time departures and arrivals and cycle dock availability.

Knowledge begets increased output and liberates resources for further investment. Its generation and use are closely related to its context: some of it will be very general, some of it location and community specific. Cities contain a concentrated mix of specialisation and diversity and economic activity which generates a fertile environment for innovation in ideas, technologies and processes. Ideas are shared and new techniques and innovations are learnt, scaled and deployed. Cities are well placed to benefit from strong action to reduce emissions while simultaneously improving resource efficiency, tackling waste, and reducing noise, congestion and pollution. The most dynamic and creative cities attract the best talent.

The physical shape of cities will determine the behaviours of its citizens and the responsiveness of its institutions. For example, providing cycle infrastructure will encourage people to invest in cycling. More cyclists will put greater pressure on politicians to provide better cycle infrastructure, a virtuous physical and behavioural spiral that encourages better physical and mental health, life satisfaction and reduces carbon emissions. A similar story can be told for pedestrianisation.

Cities have governance mechanisms and planning systems which, if they function well, can make the creation and delivery of resource-efficient and less polluting policies easier to implement: action is often more effective at the city level where policymakers are closer, physically and culturally, to their citizens than national governments. The consequences of policies on waste, transport and the urban environment are readily observable and local officials are held to account for their success or failure. At the same time, a community with a shared sense of purpose can be very fertile in innovation and ideas on how it can develop and improve.

Making cities effective can mean rethinking governance, planning and metropolitan finance. Reform of local public finances in many cases, including increased fiscal autonomy for cities and planning laws that provide mechanisms for local communities to share in the overall gains, is needed. This can help stimulate the significant private sector financing required for smart urban infrastructure development. Addressing corruption and containing the influence of local barons and mafias on town and city hall actions are also prerequisite to effective action.

Urban leaders can enable the delivery of low-carbon programmes at scale, for example, through recycling schemes, energy from waste, broadband networks, plug-in car points, integrated public transport systems, ‘smart’ buildings, congestion pricing and biking networks. These tend to receive popular support. Surveys suggest urban populations place a higher premium on sustainability, generating a popular and clearly understood mandate. Leadership and community action go hand in hand.

This is important because delaying action taken to counter climate change and aid resource efficiency will ramp up the long-term costs. This is because it is the stock of greenhouse gases in the atmosphere that has an effect on the climate, and not the annual flow into it. Every year of delay increases the stock and means the work we need to do to get back down to a stable equilibrium is harder (the same principle applies to the irreversible depletion of scarce resources).

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