Thanks to the energy crisis that we have been going through since the spring of 2022, the debate on active transport (walking and cycling) has been revived. A debate very often approached from the climate-energy angle… It is true that transport is the first source of greenhouse gas (GHG) emissions in France and that the development of bicycle use for short-distance journeys would reduce both GHG emissions and France's energy dependence.
However, this framing of the debate obscures a strong argument in favor of active transport: its health benefits.
Indeed, by inducing a certain level of physical activity, active transport – mainly bike (with or without electric assistance) and walking – help prevent a large number of chronic diseases. It has thus been established that the absence of regular physical activity increases the occurrence of serious diseases such as cardiovascular disease, type 2 diabetes, breast or colon cancer and dementia.
A simple way to engage in regular physical activity is to travel on foot or by bicycle, and several meta-analyses of epidemiological studies have shown that these modes of travel reduce the frequency of these diseases. This generates reductions in health expenditure: it is estimated that one case of diabetes prevented annually saves the community nearly 36 euros in medical expenses.
A calculated beneficial effect
Beyond these pathologies, walking and cycling have also been associated with reduced risk of death. Another meta-analysis has thus shown that the weekly practice of 1h40 of cycling reduced the risk of death (all causes combined) by 10%, and that the practice of 2h50 of weekly walking reduced this risk by 9%. At the population level, these protective effects are substantial.
For example, it is estimated that the current levels of cycling in the Netherlands would lead to a gain in life expectancy of 6 months. Strictly speaking, death generates little or no medical costs. However, governments have set the “value” of one death averted and one year of life saved, which represents the amount a society is willing to spend to save one life or one average year of life. On this basis, the bicycle would generate annual benefits in the Netherlands estimated at 19 billion euros, or, to give an order of magnitude, more than 3% of the country's GDP.
The example of the Netherlands illustrates this in an instructive way: in terms of transport, what is good for the climate is also good for health.
Therefore, rigorously documenting the health benefits of climate action from decarbonization policies can play a very important role in strengthening the commitment and support of the population and local or national authorities for GHG reduction measures.
An unprecedented assessment
It is to this exercise that we tried ourselves in a recent scientific article. Using the method ofquantitative health impact assessment, we sought to assess the health benefits of active transportation in a low-carbon transition scenario: the one described in 2021 by thenegaWatt association.
Like other scenarios (those of RTE or Ademe for example), the négaWatt scenario aims to identify a coherent transition trajectory towards carbon neutrality for metropolitan France by 2050, with a high level of detail for the main determinants of energy consumption in a variety of sectors. (passenger-km for the transport sector, heated living space in the building sector, etc.).
In the negaWatt scenario, the decarbonization of transport requires, among other things, a boom in active transport. Thus, this scenario projects on a national scale, over the period 2020-2050, a moderate increase in walking (+10%) and a sharp increase in cycling (increase by a factor of 7), mainly driven by cycling electric assist.
If this increase in the use of the bicycle seems significant, it should be kept in mind that France is starting from a low level in 2020, and that this increase is ultimately reflected in around 1 hour of weekly cycling per person on average. in 2050, which remains below the current level of bicycle use in the Netherlands, and close to the current level in Denmark.
Estimated gains in terms of lives saved and billions of euros
By distributing these increases in walking, cycling and eBike among the age groups making up the population, and by applying the corresponding mortality reductions to these levels, we were able to estimate the number of deaths averted compared to a scenario with no increase. active transportation (2021 levels held constant).
We have thus been able to demonstrate that the health gains of this scenario could be considerable, and this in the near future: from 2025, this increase in active transport would result in approximately 3 deaths avoided annually.
Using nationally recommended values for socio-economic impact assessment of public investments (one year of life saved is valued at 139 euros in 000), the monetization of these benefits amounts to approximately 10 billion euros per year.
In the longer term, by 2050, these gains would amount to approximately 10 deaths avoided per year, a gain in life expectancy of around three months on average for the entire population, and nearly 000 billion euros in profits.
At this stage, the elements of comparison are important for understanding the level of profits. For example, it is believed that an ambitious public health policy that would reduce the 20% alcohol consumption would prevent ~7 deaths per year, i.e. the number of deaths avoided thanks to physical activity induced by active transport from 2030 in the negaWatt scenario.
Concerning the associated monetized benefits (10 billion euros per year from 2025), they can be compared with public investments for the promotion of active transport... even if the comparison is not in favor of the latter: indeed, the government bicycle plan announced in 2018 represented 450 million euros over 7 years, i.e. less 65 million euros per year... A drop in the bucket compared to state aid for fuels, which represented more than 2 billion euros in public aid from April to August 2022.
Genuine health-climate co-benefits
This study illustrates that a realistic transition scenario towards carbon neutrality which articulates, in the case of the negaWatt scenario, sobriety, energy efficiency and renewable energies, makes it possible to generate benefits that go beyond the mere reduction of GHG emissions.
These co-benefits for health of climate actions go well beyond the physical activity induced by active transport: the same is true for the improvement in air quality resulting from the reduction of combustion of fossil fuels, or improving the thermal comfort of housing.
The systematic evaluation of these health benefits thus constitutes an exercise which could help to identify the most desirable trajectories, here based on the health criterion, among scenarios aiming for carbon neutrality through contrasting technical and societal choices.
Finally, this study makes it possible once again to underline the relevance of promoting active mobility, whether in view of its health benefits or the associated economic benefits, which generally far exceed the sums invested. While this observation has been the subject of consensus for many years in medico-economic studies, it is clear that it has not been translated – or only very recently – into public policy…
In 2019, it was thus estimated that only 2,7% of French trips were made by bicycle... the same figure, to one decimal place, as in 2008. In other words, public policies promoting cycling have missed out on a decade of potential benefits for France's climate goals and for the health of its population.
It only becomes more urgent to recognize the benefits of active transportation at their fair value and to allocate to them the investments they deserve.
Émilie Schwarz, student at the Master of Public Health (Ecole des Hautes Etudes en Santé Publique), contributed to this work and to the writing of the article.
A presentation of these results is planned as part of a webinar organized by the Cired next September 29.