Creating climate-friendly cities

"Encouraging people to use electric cars and scooters may be helpful for reducing carbon emissions, but this is not the all-round best strategy for creating sustainable transport in cities," says Associate Professor Ralph Chapman.

Associate Professor Chapman, from Victoria University of Wellington’s School of Geography, Environment, and Earth Sciences, is part of an ongoing research collaboration with the New Zealand Centre for Sustainable Cities (NZCSC).  Their research is focussed on creating sustainable transport for cities, by studying how cities can reduce emissions and decarbonise our economy and society through changing the way their citizens travel.

“Rethinking the transport sector is a crucial part of reducing carbon emissions,” Ralph Chapman says. “The world has well over a billion vehicles running around, and transport is responsible for about 23 percent of total energy-related carbon dioxide emissions. The global community needs to drastically cut its carbon emissions from transport to avoid potentially catastrophic climate change.”

Associate Professor Chapman’s research has looked at various ways we can reduce carbon emissions, including making cities more compact over time and making a shift from cars to active travel.

“For health reasons, we need to encourage people to shift to active travel, such as walking and cycling, as fast as possible, but pushing for active travel and making cities more compact are not easy strategies,” he says. “These policies challenge aspects of how we live. However, they also have the potential to cut carbon emissions, and there are lots of co-benefits along the way.”

One of his recent projects has been a cost-benefit analysis of the major benefits of active travel weighed against the costs of infrastructure and support for people to shift to this method of transport.  Associate Professor Chapman collaborated University of Otago Wellington researchers, particularly Associate Professor Michael Keall and Professor Philippa Howden-Chapman in public health, on this project.

“The findings from this study showed that, together, the health and environmental benefits of active travel outweighed the costs by around 10 to 1,” Associate Professor Chapman says. “We were able to show that building cycleways and good walking links, as well as promoting active travel, is effective in changing people’s travel habits.  There is a strong return on investment for city councils and central government in implementing these policies.”

The health benefits from physical activity are the biggest plus, but carbon emission reductions are also increasingly valuable, Associate Professor Chapman says. This comes at a moment when there is stronger evidence of the benefits of avoiding air pollution – which sprawling cities and fossil fuelled vehicles are partly responsible for.

Associate Professor Chapman and his colleagues have published several articles in this research area so far, with at least one more study to come. This work is part of Associate Professor Chapman’s research interest in the wider issues surrounding cities and climate change.

“I am looking at whether we can achieve better quality of life, while at the same time cutting carbon emissions through developing our cities more intensively – at least, along public transport corridors and in places where people want to live in apartments and town houses,” he says. “By avoiding urban sprawl, and doing compact development well, we may be able to achieve a win-win in terms of reducing vehicle carbon emissions, increasing physical activity, and improving quality of life.”

To find out more about Associate Professor Chapman’s work, visit his publications page or the website of the NZCSC.