Article

Is cycling sustainable?

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During the end of my bachelor, while attending a lecture of one of the professors on the faculty of architecture, I was confronted with the question posed in the title of this column. As you yourself might think right now, my first reaction was: Yes, of course! Bicycling is a very sustainable activity, especially when you compare its’ ‘ín-use’ carbon footprint with the one from a car or a plane. Since it seemed so obvious for me that the answer was or should have been ‘yes’, I was very interested in other ways to look at the subject.

Andy van den Dobbelsteen, the professor who held the two hours during lecture, told us that he himself once asked the same question. To come up with a ‘scientifically based’ answer he had calculated the amount of energy it took him to get from point A to B by bike. In this calculation he included the amount of energy that was needed to grow his food, how much food he had to ate to supply his body with enough energy to be able to cycle the specific distance, the efficiency of his body to turn food into energy, and the efficiency of the energy used by our body when we cycle. In the end, the outcome was that cycling, from this point of view, was not sustainable at all!

 

However, sustainability as a concept should not be defined only by the criteria based on this point of view. Sustainability is so much more than that, for instance one should consider incorporating the concepts of embodied energy and public health as well. When done so, you could think of bicycling as an environmentally sustainable activity in cities again;

 

Of course, depending on the type of bike and other vehicle intended for transport some variations exist, but the amount of energy required to produce a bicycle is far less than many other forms of transport. For example, a bike of about 7 kg with a carbon frame uses about 11.5 billion Joules of energy during production, a generic car however takes up to about 10 times as much energy during its production process. In addition, also the construction of bicycle lanes is less energy intensive than roads for cars, requiring less space and material.

The effect of the bicycle’s environmental sustainability doesn’t stop here. If more people start using bikes, which in use are zero emission ones, instead of more polluting ways of transport, there is potential for overall reduced carbon emissions and an improved air quality in our cities. Pollution however, is about more than just carbon emissions; noise levels in cities can also be considered a pollutant, so by switching from noise generating ways of transport to bikes, a reduction in noise pollution will be achieved as well. Therewith both contributing to better public health.

In addition to better air quality and reduced noise pollution, cycling could also achieve improved health by means of decreased health risks due to extra body exercise.

 

So, to be able to conclude on the question whether or not bicycling is a sustainable activity it is important to define the concept of sustainability and its criteria, since different points of view could have different outcomes