By akademiotoelektronik, 19/12/2022

The more ecological car than cycling?- Auto environment

JEAN-LUC MOREAU – RIGHT OF REPLY (updated June 11, 2015):

It is undoubtedly necessary to provide some details on our article which has caused a lot of ink to flow. First of all, the point was not to prove that the car is more ecological than the bicycle... It was up to you to challenge. And we can say that the objective was achieved beyond our expectations!

With these convoluted calculations (whose basic information is easily verifiable on the Internet) the idea was to make everyone aware that there is no right and wrong solution when it comes to transport . All have advantages and all have disadvantages. All these figures show that, contrary to popular belief, with a global approach that takes into account the carbon footprint of the food consumed by a cyclist, its impact in terms of greenhouse gases is not zero. Admittedly, our cyclist can also grow vegetables in his garden, raise chickens, fish or hunt along the way and his CO2 emissions/km will then be minimal. But, is this a common case?

Conversely, the automobile is probably stigmatized too much. Admittedly, it emits local pollutants harmful to health, but their level has become extremely low for vehicles that meet the euro 6 standard. Admittedly, we see more often a vehicle with only one person at the wheel than with 5 passengers on board . But, accusing him of all the evils is very exaggerated. Recent cars, like our Peugeot 208 BlueHDI, manufactured in factories with strict environmental standards, easily recyclable and fuel efficient are not, even in a global approach, terrible CO2 emitting machines.

Moreover, in France, depending on the sources, private vehicles are only responsible for 15 to 18% of total CO2 emissions. Nothing to throw the baby out with the bathwater...

We believe that, even if you do not share our opinion, this article will at least have had the merit of making you think about the question. Nothing is all black, nothing is all white... It's good to shake the spirits from time to time to remind you. Finally, we would add that it is quite jubilant to be called "idiot" by Liberation, a newspaper which did not hesitate, a few years ago, to publish an article whose conclusions were that the electric car pollutes more than diesel (see the article here)!

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The bicycle has always been presented as a mode of transport that respects the environment and the automobile as a polluting means of transport, responsible for global warming, in particular. Moreover, we no longer speak today of horsepower, but of CO2 emissions, like the new Peugeot 208 1.6 HDI proudly displaying its 79 g/km. Still too much in the eyes of militant radical ecologists for the replacement, pure and simple, of the car by the bicycle. Admittedly, it is good for health, it does not produce local pollutants (CO, NOx, Pm), but it is not very profitable in terms of CO2.

Let's forget the carbon dioxide emitted by our normal breathing, i.e. 50 g/h, and take the example of a good level cyclist: a 70 kg man, whose bike and complete equipment weigh 20 kg, and who travels on a flat road, without wind, at a temperature of 20°C, at a speed of 30 km/h. To provide this effort, it develops a power of 200 W (Tour de France riders exceed 400 W).

If it travels 100 km, it will therefore drive 3.20 hours and use 666.6 Wh of energy. Given the efficiency of human metabolism (about 25%), it needs the equivalent of 2.67 kWh of power to cover such a distance. And this is where the matter gets complicated. If our cyclist draws his strength from meat, and knowing that a kilo of ground beef provides 2.9 kWh of energy, he must therefore eat 0.917 kg to complete his journey. As long as it is beef imported from Brazil (the world's largest producer), its carbon footprint becomes simply appalling.

The bike is worse than the car but better than running?

According to the International Journal of Life Cycle Assessment, the reference journal in the field of life cycle assessments, the consumption of 0.917 kg of beef from Brazil contributes to emitting 307 kg of CO2, or 3,070 g/km… when a 963 hp Ferrari LaFerrari emits 330 g/km! Our cyclist can also eat French beef, you might say. In this case, still according to the IJLCA, CO2 emissions drop to 20 kg to travel 100 km, i.e. 200 g/km… like a Porsche 911 Carrera!

If his ecological conscience forbids him beef, our cyclist can turn to chicken, the meat with the lowest carbon footprint (6.2 kg of CO2 per kilo). A kilo of chicken containing 2.54 kWh of energy, he must eat 1.05 kg for his journey, or 65 g/km of CO2. Finally, if this sportsman eats exclusively… tofu, the food with the lowest carbon footprint of all (3.8 kg of CO2 per kilo), but with a low energy content (1.65 kWh/kg), he will have to eat 1.61 kg.

In the end, its CO2 balance (61.2 g/km) will be barely better than with chicken! This is better than the 79 g/km of the 208 HDI, except that it can carry five people. This brings CO2 emissions down to 15.8 g/km per person. Even taking into account the complete life cycle of the vehicle (its manufacture, its recycling and its fuel with refining, prospecting and transport), our Peugeot emits a total of 103 g/km of CO2, i.e. 20.6 g/km per passenger. This is still three times less than the cyclist!

The use of bicycles is therefore no more effective than the car in combating global warming. And it's even worse for running...

Also see:

Ecology – Pollution peaks: a state lie

Health - Diesel particulates? Not carcinogenic!

Biofuel: ethanol in 6 questions