As mentioned in my previous post, the International Energy Agency (IEA) estimates that at the end of 2010 the numbers of cars on the planet surpassed 1 billion. Although it varies from country to country, globally about 15% of CO2 emissions come from transportation. While this includes other modes of transportation, cars are an important contributor to global climate change.
Currently, personal mobility is highly unsustainable for the following reasons: 1) almost total dependence on fossil fuels, 2) inefficiency of internal combustion engines, and 3) continued demand growth for cars. Let’s explore these one by one:
- Almost total dependence on fossil fuels: Although hybrid cars and electric vehicles are becoming more widespread, fossil fuels dominate globally. Diesel cars consume less fuel than gasoline cars, thus emitting less CO2, but they tend to emit much more fine particulates which even the most efficient particulate filters fail to eliminate. Fossil fuels are also a finite resource. While there is plenty left, it is one of the few natural resources which cannot be recycled. Once it is burned inside the ICE engine, it is gone. Platinum and other precious metals, on the other hand, are recycled to a high degree. The development of biofuels tried to change our dependence on fossil fuels, but has so-far not been successful in reducing our addiction to fossil fuels. 1st generation biofuels compete with the food crop and 2nd generation (ligno-cellulosic) and 3rd generation (algae-based) biofuels are currently in pilot stage. Full electric cars, although in early stage of adoption (0.07% of the global car fleet), show tremendous promise, especially when the electricity would be derived from renewable energy sources, such as hydropower, solar and wind. The same holds for fuel cell powered cars.
- Inefficiency of the internal combustion engine: The internal combustion engine (ICE) is highly inefficient. ICE engines generate a lot of heat and this heat cannot easily be recovered without adding lots of weight to the car. Although it varies from country to country, about 75% of the energy in an average US car is lost through the exhaust. The remaining 25% is used as follows: 8% mechanical losses (wheel bearings, etc.), 15% to move the car, and 2% to move the average. In Europe and Japan, it is slightly better because of the use of smaller engines, but the challenge of heat losses is difficult to address in traditional ICE engines. The hybrid drive, commercialised on a large scale by Toyota, now dramatically improves the efficiency of ICE engines due to energy recovery from braking and deceleration.
- Continued demand growth for cars: Some experts expect cars to reach 2 billion by 2035. In my previous post, I challenged that projection because of changes in technology and ownership models. In Europe and Japan, car ownership is slowing and in some instances declining. According to the Boston Consulting Group, young people (18-29 year old) buy fewer cars in countries such as Germany compared to young people a decade ago. William Clay Ford, Jr, the grandson of the founder of Ford Motor Company famously said: “If you live in a city you don’t need to own a car”. Nevertheless, it is expected that globally, the demand for cars will continue to grow, especially the demand for traditional ICE powered cars, although hybrid cars and full electric cars are gaining momentum.
In the next post we will explore regulatory factors in Europe, the US, and China and how they developed over the years.