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How will we want to get around in 2050?


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The Conversation

Arturo H. Ariño

researcher from high school of Biodiversity and Environment and director scientist of the Science Museum of the University of Navarra.

It has now been five years since Spain ratified the agreement Paris climate agreementbut it is now that the project of the Climate Change and Energy Transition Law has just been posted on C after an urgent procedure.

It is to be hoped that the essay of project has not been subjected to the same haste as its parliamentary journey. The extensive list of prescriptions and proscriptions in the text seeks to halt or reverse part of the environmental deterioration before 2050. But in order to do so, it has to deal with superior laws (physical, ecological, mathematical) of unassailable stubbornness. We will assume that a very thorough prior study of each component or derivative of the law will have been carried out by the best scientific and technical team, because playing with the environment, an extraordinarily interconnected system with numerous components (the atmosphere, the oceans, the carbon cycle, radiative forcing, biodiversity...) in which any change in one compartment is transmitted to many others, is like playing chess: to see the next move is easy, but to win the game you have to foresee more.

The laws of physics tell us that emitting greenhouse gases (GHGs) warms the planet through radiative forcing, so it is advisable to reduce them. The project law takes up the challenge in one of its most striking regulations: the ban on the circulation of cars that are not zero-emission vehicles (ZEVs) from 2050 onwards. In this way we would avoid emitting 75 million tons of CO2 into the atmosphere that year, if we project the data emissions of the National Greenhouse Gas Inventory (GHG). Or about 980 million in the EU as a whole.

Will this reduction have an effect? It will depend on the rest of the pieces on the board: society, which decides the moves, and natural laws, which set the rules.

For the measure to be useful, the reduction in emissions must be net and B. The cars affected by the rule accounted for 19% of the net CO2 equivalent emissions in Spain in 2019, but their elimination would only free a part of that footprint, because generating in Spain the energy that would move them entails today (hopefully less by then) equivalent emissions of 33%.

The law includes other rules that promote renewable generation, such as the transition to hydrogen. A very appropriate measure for CSVs, provided that its storage is solved (stubborn thermodynamics does not financial aid) and its generation is improved: currently 95% is extracted from natural gas, leaving as a by-product... CO2.

Surprising as it may seem, the carbon footprint of an electric ECV can be equivalent to that of a gasoline car. CO2 emissions during the manufacture in Europe of an electric car are twice those of a conventional car, mainly due to the environmentally costly manufacture of the batteries. Until it has traveled 76,000 km, its footprint does not balance out. In Australia, where electricity doubles the European carbon footprint, it would not even out until near the end of its useful life. In the absence of a technological revolution, it could be that, on a global scale, the elimination of thermal cars would have little impact on GHGs.

But, in addition, it is about changing more than 24 million vehicles in Spain, and there the laws of nature could checkmate the rule.

Unless we resort to nuclear batteries (a solution waiting for a problem), we cannot change the Faraday constant, which imposes a strict limit on the storage density of electrochemical batteries. To move an electric ECV further, more mass must be added to the battery, and this additional mass (about 300 kg) requires more energy at each acceleration, Newton dixit. Switching to ECVs is a must, but with current technology and range it may mean a net increase in energy consumption. 24 million cars with 300 kg extra is accelerating 7.2 billion extra kilograms.

Why not reduce weight and therefore consumption? Cars drive on roads where it would be feasible to embed conductors or inductors. If ECVs could draw energy from the road while driving, they could be designed with much lighter batteries (say 30 kg), with less autonomy but sufficient for off-road travel. We would avoid the monumental environmental impact and resource cost of manufacturing millions of tons of batteries. Now extrapolate to the rest of Europe (or the world) and the figures are dizzying.

The concept (a form of Road-Powered Electric Vehicle) is not new. It is halfway between the trolleybus and the scalextric, and there are ongoing experiments and patents.

But there is still room for a more radical movement: changing the social paradigm of the private vehicle.

Cars are usually stationary: in a Spanish capital, about 98% of the time. If technology enables fully autonomous driving by 2050 (which is not far-fetched, being just around the corner), asking our subcutaneous assistant for an ECV at the door in two minutes (or picking up a free parked one) to go somewhere without worrying about parking is a trivial evolution that, quite possibly, will seem as natural to us in 2050 as it is today to order a pizza from the assistant on the phone.

So why would it be necessary to manufacture 24 million batteries for 24 million still ECVs, if we only need the service of a couple of million moving ECVs?

The 19 years remaining until 2040 when thermal cars can no longer be sold could be invested in converting the current industry and installing infrastructure. Our cities would gain in space and comfort.

But above all, the environment would gain if we save 22 million cars. At twelve tons of CO2 each.