Time to Clear Out "Ecological" Misconceptions

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Writes Luboš Motl at The Reference Frame:

... the political mood dictates to expel the combustion engines from the city as soon as possible. Would the transition to electric cars solve the problem of the dust?

In every average day of the year 2015, automobiles have pumped 475 kilograms of fine dust into the atmosphere above Stuttgart. Out of this amount, only 77 kilograms arose from exhaust fumes. The remaining 398 kilograms, i.e. 84 percent, is caused by wear and abrasion of tires and brakes (occurring due to rolling drag of the wheels and the friction associated with braking) and by resuspension of particular matter and street dust (re-circulation of the dust temporarily sitting on the road). And this bulk of the pollution is the same for electric cars and cars with combustion engines. The conclusion is clear: this pollution may be affected by the character of the drive but the difference that depends on the source of energy is negligible.

For that reason, Klinke says that the bans "discriminating" against the combustion engines are unjustifiable by the empirical data. In the rest of the interview, Klinke discusses various other sources of pollution, their importance (gas boilers may compete with the cars when it comes to particulate pollution), and other details. Instead of regulations blocking the access of cars, he defends smooth transportation and more frequent and thorough cleaning of the streets as the right moves to make the air (even) cleaner.

I think that it's important to realize that only the pollution that does create particulate matter or condensation nuclei really matters. Compounds that remain pure gases get quickly diluted in the atmosphere and their concentration is far too low to affect our breathing let alone to be toxic. Along with the totally solid dust, nitrogen and sulfur oxides are bad exactly because they can turn into stuff that attaches to our lungs and tissues.

Needless to say, the electric cars also require some electricity – to recharge the batteries from the grid etc. – that needs to be produced. Some of it is produced by burning coal which may add some additional pollution to the air. When this contribution is added to those 84% above, it's likely that the electric cars actually pollute the air more than the fossil-fuel-based cars do.

The measured numbers quantifying the pollution on the streets are just one example of the data that the relevant people should re-evaluate from scratch. It's time to realize that everything we thought to know – and many of our knee-jerk emotional reactions to various environmental issues and their proposed solutions – may be wrong. In particular, all subsidies and advantages favoring the electric cars and their access to the urban centers are based on a misevaluation of the cars' effects.

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