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Could COVID-19 be a chance to make cities carbon neutral, liveable and healthy?

29 Apr 2020 | 0

Mark Nieuwenhuijsen from ISGlobal explores how we might turn the greatest public health crisis of our time into a catalyst for change.

COVID-19 has hit the whole of society hard. A collateral victim of the current pandemic may be all the actions addressed to manage the climate crisis. This is evidenced by, for example, the postponement of the COP26 summit. Furthermore, the ambitious European Green Deal funding priorities may be overtaken by those for the COVID-19 pandemic. A short-term emergency threatening necessary long-term requirements is nothing new but does it need to be this way? Can’t we create a win-win scenario?

The COVID-19 pandemic requires a large financial stimulus package but this also creates opportunities for change, possibly for the better. We cannot simply continue the way we did and therefore any stimulus packages should be holistic, not only including requirements and indicators for the economy but also for equity, sustainability, liveability and health. The money can only be spent once, so we might as well do it in a way that will save more lives in the long term and create a more just, sustainable and liveable society.

According to data from the United Nations, 55 per cent of the world’s population live in urban areas, a proportion that is expected to increase to 68 per cent by 2050. Suboptimal urban and transport planning in cities has led them to be hotspots of air pollution and noise, heat island effects and lack of green space. What are the effects of these conditions?

Outdoor air pollution alone kills 9 million people a year – a number that could be significantly reduced as the current COVID-19 pandemic has shown. A recent health impact assessment study in Barcelona found that around 20 per cent of premature mortality was due to factors related to suboptimal urban and transport planning. Cities are also large emitters of CO2, one of the main factors behind the climate crisis.

Cities might be the problem but they’re also the solution, as they’re centres of innovation and wealth creation and tend to be more responsive and agile in their governance. As part of any stimulus package, cities could and should take measures to become carbon neutral, more liveable and healthier by changing their current urban and transport planning practices. Some measures to be taken are as follows:

Land use changes

To address this, several issues must be considered. First of all, higher population and development density lead often to shorter travel distances because destinations become closer to origins. It is also important to have diversity, characterised by a mix of homes, shops, schools and workplaces in an area. And, finally, a better design that includes connectivity and infrastructure for cycling and walking should be the aim. All of which lead to more walking, cycling and public transport use and reduced car use.

The actual design, use of space and traffic, and air quality and green space management are important. For example, in Barcelona a new urban model is proposed, the so-called Superblock (SuperIlles in Catalan), which aims to recover public space for people and thereby reduce car use, air pollution, noise and temperature levels, as well as increase green space and physical activity. It could prevent almost 700 premature deaths annually.

Reduce car dependency and shift to active transportation

Currently, there are around 1 billion cars in the world and this number is likely to rise: at times, it looks like cities are made for cars instead of for people. Electric and autonomous cars have been suggested as solutions to air pollution and noise, but they do not address the lack of physical activity and still use a lot of public space that could be used better.

A large number of car trips (as high as 50 per cent) are less than five kilometres long and these could easily be replaced by other modes of transport, such as cycling. Cycling has many advantages – for example, it reduces premature mortality; it combines transport with the gym (many people don’t have time to go to the gym); it does not cause air and noise pollution; it emits zero CO2, it uses much less space than the car; and cyclists tend to be happier than other transport users.

A recent study in 167 cities in Europe found that more than 10,000 premature deaths could be avoided annually if the bicycle modal share increased by 25 per cent in these cities. Cycling has important prerequisites, though, such as the availability of safe cycling infrastructure, including segregated cycling lanes.

Greening of cities

Greening cities has obvious benefits, such as air pollution, heat and noise mitigation, carbon sequestration and offsetting carbon emissions. Behind all these effects, there are plenty of health benefits: longer life expectancy, fewer mental health problems, better cognitive functioning, better mood and healthier babies.

As an example, a recent study estimated that more than 400 premature deaths overall, including more than 200 deaths in areas of lower socio-economic status, could be prevented annually in Philadelphia, if the city were able to meet its goal of increasing tree canopy from its current 20 per cent to up to 30 per cent.


What may be lacking in many cities is probably a vision of what is a sustainable, liveable and healthy city, and how to translate this vision into standard operating procedures. There is no cook book out there on what are the ingredients of such a city and how to prepare it. But it is urgently needed.

A number of cities have a vision to become car free; for example, Hamburg envisages to be car free by 2034. The main driver is climate action but the policy may also bring many benefits for liveability and health. A good example of a car-free neighbourhood is Vauban in Freiburg, Germany.

Citizen involvement

There is also a need to involve the citizens more. Where in the past many larger developments were top-down, nowadays there is a large need to involve the community and citizens in any urban and transport planning development, and have a bottom-up approach.

An interesting and novel approach has been taken by the Ringland project in Antwerp, Belgium. This initiative is a €6 billion investment that proposes a large-scale sustainable urban development focusing on a complete redesign of the highway system in the city of Antwerp. The research underlying this complex infrastructure project has been entirely organised by local citizens in bottom-up fashion. Detailed research studies, executed by external academics, were financed through crowdfunding and subsequently presented to government.

Collaboration, leadership and investment

There is a large need for collaboration to improve cities. This requires collaboration between urban and transport planners, architects, the education sector and health professionals, to name a few. Good leadership and the right investment are essential, and mayors and their teams need to take the lead and direct investments that benefit these different aspects in cities. Unfortunately, too often, we find a lack of leadership and focus and too many silos in cities.

There are some bright spots though. Cities have taken the lead on sustainability and the climate crisis and are more networked than ever. They have enhanced their capabilities by working together, sharing experiences and forging public–private partnerships across health, governance, democracy, infrastructure and security. Formal networks include C40 Cities Climate Leadership Group, the Rockefeller Foundation’s 100 Resilient Cities, United Cities and Local Governments (UCLG), ICLEI Local Governments for Sustainability, and the World Health Organization’s (WHO) Healthy Cities.

Systemic approaches

Cities are complex systems and to address their challenges we need system approaches taking into account many different factors. It requires an effort to install this type of thinking and action; it ticks many boxes but it also takes into account feedback loops. It is important that we have a more holistic approach to our cities, addressing health, liveability, sustainability, climate change and equity simultaneously.


Finally, we know that environmental exposures and lifestyle factors, and thereby health, are often not equally distributed through cities. We see gradients of life expectancy in cities, and they can partly be explained by these different factors. In any of the proposed measures, equity should be fully considered


Better urban and transport planning can lead to carbon-neutral, more liveable and healthier cities. The COVID-19 pandemic requires a rethink of our cities as, for example, social distancing measures are likely to stay in place. Now may be the time to turn a tragic public health emergency into a great catalyst for change for the better.

This blog is based on the following scientific article: Nieuwenhuijsen, M. Urban and transport planning pathways to carbon neutral, liveable and healthy cities; a review of the current evidence. Environment International; 2020. Published 16 April 2020.

About the author

Mark Nieuwenhuijsen PhD is a research professor, director of the Urban Planning, Environment and Health Initiative, and director of the Air pollution and Urban Environment Programme at ISGlobal, in Barcelona, Spain.

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