Cities are key places. Changing the way we plan and develop cities will be essential to meet our net zero targets as well as improve the health and lives of people in urban areas. In this blog, Professor James Evans, Dr Luke Munford, Professor David Topping, Professor Sheena Cruickshank and Dr Jamie Anderson explore the interlinked challenges of climate change, health and urban development, and outline policy recommendations to build healthier, climate-resilient cities.

• By the end of this century 85% of humanity, some 9 billion people, will live in urban areas.
• Environmental conditions and human health are interrelated; factors such as low-quality housing, air pollution and lack of access to green space are determinants of poor health.
• More robust evidence is required to study the systemic interactions between developments and health outcomes and to help avoid unintended policy consequences.
• Creating longer-term, multi-stakeholder partnerships with local communities will drive transdisciplinary research and deliver better local outcomes.

By the end of this century 85% of humanity, some 9 billion people, will live in urban areas. The morphology of cities defines their environmental impact through such things as carbon emissions and air quality. But it also defines human health. Cities that enable people to switch from sedentary commutes, such as cars and public transport, to active commutes like cycling and walking will improve physical and mental health as well as reducing emissions. Cities lock in resource use patterns, behaviours and health outcomes. What is bad for the planet is bad for human health, and vice versa. An effective way to simultaneously improve health and the environment is building better cities.

Interlinked challenges of climate change and health

The relationship between environmental conditions and human health has been highlighted by climate change. At 1.5°C of warming, the Intergovernmental Panel on Climate Change (IPCC) project that twice as many megacities could become heat stressed, exposing more than 350 million more people to deadly heat by 2050. Almost 10 million people in England live in areas with very limited access to green space, despite growing evidence that green space improves human health and mitigates urban heating. Furthermore, over 90% of the world’s city dwellers breathe dangerously polluted air. This includes children who are exposed to air pollution on their daily journeys to and from school, which reduces their educational attainment, as well as their overall life expectancy and career earnings. Human health is increasingly moving up political and public agendas, and represents a key lever to rapidly change cities.

What we build now will last for at least 30 years, locking in health outcomes and sustainability performance past 2050, which means we need to get it right. Greater Manchester has ambitious net zero targets for 2038 and the UK government plans to achieve net zero by 2050. This ‘low carbon transition’ provides an opportunity to rethink area-based initiatives towards addressing the interlinked challenges of climate change and health. Yet, radical transformations to the built environment, economy and ways of life are required to achieve the pace of change that is required. For example, encouraging cycling and walking requires remodelling streetscapes and dis-incentivising car use for short journeys. Electric vehicles require reskilling mechanics, upgrading the electricity distribution grid, and altering streets to provide charging for houses without off road parking. Rapidly changing cities is no easy task.

What makes a city healthy?

Regarding building healthy cities, there is surprisingly little robust evidence concerning how different forms of urban development improve mental and physical health. The recent Marmot Report on health inequalities in Greater Manchester identifies low-quality housing, air pollution, lack of green space, and unsustainable transport as key determinants of poor health that drive inequalities. The Index of Multiple Deprivation (IMD) similarly synthesises indicators relating to employment, income, health, crime, and housing to gain insights as to how and where these factors intersect. This work was fundamental in shaping urban regeneration policy in the UK, leading to the focus on area-based initiatives that sought to transform places holistically. The IMD articulates what most of us implicitly know – neighbourhoods shape outcomes for those that live there. However, the evidence that regeneration programmes improve health or socio-economic outcomes is mixed.

Building better cities requires robust evidence about the causal pathways between different types of development and outcomes and investigating the longer term health impacts of urban regeneration schemes. Studies of this kind raise a number of scientific and evaluative challenges. Health behaviours are complex, requiring multifaceted interventions and a composite evaluation framework. Evaluations of urban developments need to be flexible enough to cope with unpredictable implementation and a changing environment. Furthermore, longitudinal data on individuals over long enough periods of time to effectively evaluate outcomes is hard to come by. A better urban evidence base would shed light on systemic interactions and help avoid unintended consequences. The damaging effect on air quality and health as a result of promoting diesel engines in the 1990s or, more recently, the adverse impact of planting exclusively male trees on hay fever in cities provide salutary examples here. In addressing one problem it is important we do not create another.

Collaborative, area-based, technological approaches

There are a number of reasons to think that the time is right to address these challenges. Urban developers are now making longer-term commitments to regeneration schemes, driven partly by their increasing scale, but also the need to demonstrate broader social and environmental value in order to win tenders. This allows collaboration between municipalities, anchor institutions and developers, where all parties involved recognise the opportunity and value of understanding the long-term impacts of urban development on communities. Deeper, longer-lasting partnerships hold the potential to develop genuinely transdisciplinary research, developing, undertaking and applying research with non-academic stakeholders over long time periods.

New tools, technologies and data analytics make it easier to monitor environmental conditions, the use of spaces, and personal health and wellbeing. Wearable health sensors can link the health of individuals to the spaces they occupy, allowing us to understand what people are actually exposed to through their daily lives. Technology enables longer term and more holistic forms of monitoring, and opens the potential to develop digital twins that offer a forward planning capability to show the potential impacts of future interventions in the urban environment. Effective interfacing between academic and policy worlds is an important enabler for creating trustworthy data, in terms of developing open regulatory frameworks and inclusive methodological approaches.

Finally, governance is increasingly integrated around the delivery of better local outcomes. The Greater Manchester model of public service delivery means organising resources around neighbourhoods, rather than around policy areas. In the UK, the poor record of urban regeneration programmes in reducing spatial health disparities has been attributed to an over-emphasis on physical regeneration at the expense of understanding the personal circumstances of residents. Bringing government functions together to focus on local outcomes promises a way to better align physical regeneration with social and health outcomes.

Creating healthy cities holds the potential to improve peoples’ lives and address environmental challenges. As the domains of health, environment and urban development become increasingly entwined, fostering interdisciplinary research and holistic partnerships can make this happen.

This article was originally published in Building Utopia, a collection of thought leadership pieces and expert analysis on urban development, published by Policy@Manchester.

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