Walking, cycling and e-biking can help to mitigate climate change

Emission reduction targets for transport are unlikely to be met without a significant move away from motorised travel.

Technological fixes such as electrification of the vehicle fleet will not be sufficient and will not happen fast enough to make the sort of difference we need in the time period that we need change to happen.

However, a new study spells out the potential importance of active transport in achieving emissions reduction.
  

Shifting to active transport could save as much as a quarter of personal CO₂ emissions from transport

Published in the journal Global Environmental Change, this is the first international study of the carbon-reducing impact of city-based lifestyle changes.

The study reveals that increases in active mobility significantly lower carbon footprints in urban settings, including in cities that already have a high incidence of walking and cycling.
  

What does the study tell us?

The study followed nearly 2,000 urban residents over time.

And it found that those who switch just one trip per day from car-driving to cycling reduced their carbon footprint by about 0.5 tonnes over a year.

This represents a substantial share of average per capita CO₂ emissions.

If just 10% of the population were to change travel behaviour in this way, the emissions savings would be around 4% of lifecycle CO₂ emissions from all car travel.
  

What does this mean for carbon emissions?

To put this into context, for the cities in this study, the average per capita CO₂ emissions from transport (excluding international aviation and shipping) ranged between 1.8 tonnes of CO₂ per person per year in the UK to 2.7 tonnes of CO₂ per person per year in Austria.

According to the Global Carbon Atlas, the average per capita CO₂ emissions from all activities were eight tonnes per year in the UK (on a consumption basis).

Active travel replaces car travel

The study addresses one of the ‘urban myths’ of transport – trips made by walking and cycling are often considered to be additional to motorised travel, rather than replacing it.

However, we found that active travel substitutes for motorised travel.

This is vital empirical evidence that travel by car and public transport reduces as active travel increases.

And an increase in cycling, e-biking or walking over time lowers daily mobility-related lifecycle CO₂ emissions.   

So swapping the car for a bike or e-bike for just one day a week – or going from not cycling to cycling – drastically lowers mobility-related lifecycle CO₂.

The largest benefits from shifts from car to active travel are for business travel, followed by social and leisure trips, and commuting to work or place of study.

The finding that those who already cycle have 84% lower CO₂ emissions from all daily travel than non-cyclists further emphasises the importance of active travel.
  

What does all of this mean?

The analysis comes as we embark on a critical ‘decade of action’ if global goals to limit rising temperatures are to be met.

Ahead of this November’s COP26 UN climate summit in Glasgow, countries are expected to submit enhanced pledges to tackle emissions.

The findings suggest that, even if not all car trips could be substituted by bicycle trips, the potential for decreasing emissions is huge.

Active travel promotion needs to be part of the carbon emission reduction strategy for all cities.

How was the study carried out?

The scientists collected primary data on daily travel behaviour, journey purpose, as well as personal and geospatial characteristics in seven European cities:

• Antwerp
• Barcelona
• London
• Örebro
• Rome
• Vienna
• and Zürich.

They also looked at derived mobility-related lifecycle CO₂ emissions over time and space.

‘Lifecycle’ emissions included:

• emissions at the point of use (pollution coming out of the tailpipe)
• emissions from the energy supply of petrol, diesel, and electricity
• and emissions from the manufacture, maintenance and recycling/disposal of vehicles and batteries.

Statistical modelling of longitudinal panel data of 1,849 study participants was performed to assess how changes in active mobility, the ‘main mode’ of daily travel, and cycling frequency influenced changes in mobility-related lifecycle CO₂ emissions.
  

What can we do?

A typical response to the climate crisis is to ‘do more of something’, such as planting more trees, or switching to electric vehicles.

While these are important and effective in the long run, they are neither sufficient nor fast enough to meet our ambitious climate targets.

Doing more of a good thing combined with doing less of a bad thing – and doing it now – is more compliant with a ‘net zero’ pathway and preserving our ‘perfect planet’s’ and our own futures.

Switching from car to active travel is one thing to do which would make a real difference.

And the scientists show how good this can be in cities.

Not just for the climate but also for reducing social inequalities and improving public health and quality of urban life in a post-Covid-19 world.

Cities across the world will need to increase investment in high-quality infrastructure for pedestrians and cyclists. 

And they need to incorporate policy and planning concepts that require a fairly radical rethink of how we re-design and use our cities – think 15 or 20-minute city.

Beyond the ‘carrot’ of making it easier, safer and more enjoyable to travel actively, increasing the cost of car ownership and use, limit car parking, limit car access to city centres or even ban cars altogether have seen significant mode shift to active (and public) transport.

Highlighting potential health and air pollution ‘co-benefits’ of active travel can increase public acceptance of regulation of private car use to reduce an individual’s carbon footprint.

Download and read the full report on ScienceDirect.

Take a look at our list of things you can do to help reduce air pollution.