Which is Greener: the Prius or the Hummer?

The Recorder argues that when the environmental costs of building a Prius are factored in -- such as mining the nickel for its battery -- the race between the Hummer and the Prius for the Green Riband isn't even close. (hat tip: Samizdata) A quotation from the article demonstrates the power with which a change in perspective can alter the accounting of what seemed at first glance to be an easy decision.

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As already noted, the Prius is partly driven by a battery which contains nickel. The nickel is mined and smelted at a plant in Sudbury, Ontario. This plant has caused so much environmental damage to the surrounding environment that NASA has used the ‘dead zone’ around the plant to test moon rovers. The area around the plant is devoid of any life for miles.

The plant is the source of all the nickel found in a Prius’ battery and Toyota purchases 1,000 tons annually. Dubbed the Superstack, the plague-factory has spread sulfur dioxide across northern Ontario, becoming every environmentalist’s nightmare.

“The acid rain around Sudbury was so bad it destroyed all the plants and the soil slid down off the hillside,” said Canadian Greenpeace energy-coordinator David Martin during an interview with Mail, a British-based newspaper.

All of this would be bad enough in and of itself; however, the journey to make a hybrid doesn’t end there. The nickel produced by this disastrous plant is shipped via massive container ship to the largest nickel refinery in Europe. From there, the nickel hops over to China to produce ‘nickel foam.’ From there, it goes to Japan. Finally, the completed batteries are shipped to the United States, finalizing the around-the-world trip required to produce a single Prius battery. Are these not sounding less and less like environmentally sound cars and more like a farce?

Wait, I haven’t even got to the best part yet. When you pool together all the combined energy it takes to drive and build a Toyota Prius, the flagship car of energy fanatics, it takes almost 50 percent more energy than a Hummer - the Prius’s arch nemesis.

Through a study by CNW Marketing called “Dust to Dust,” the total combined energy is taken from all the electrical, fuel, transportation, materials (metal, plastic, etc) and hundreds of other factors over the expected lifetime of a vehicle. The Prius costs an average of $3.25 per mile driven over a lifetime of 100,000 miles - the expected lifespan of the Hybrid.

One of the most subtle problems in public policy is to decide what exactly one is trying to optimize. By changing the definition of Green-ness to include total pollution rather than simply minimizing a "carbon footprint" it may well be the case that a Hummer is Greener than a Prius. But given that Canada is a friendly country an energy security case might be made for being more dependent on nickel from Ontario than oil from Saudi Arabia. By that measure a Prius might be better than a Hummer. The sage advice of all public policy professors is to redefine a problem until it is expressed in terms favorable to one's self. And, faced with the energy security argument, it might be countered that since a Prius is made by a "foreign" corporation, then that additional factor might make it "better" to buy a Hummer after all. And so on.

The sad fact about most of these environmental question is that it may require us to trade off one set of objectives against another. Maybe the "world" should decide which it values more. In the case of "Global Warming" for example, many of the policies designed to reduce "Greenhouse Gases" may exacerbate poverty in the Third World. How does one rank different goals -- such as for example reducing "greenhouse gases" and reducing hunger -- and combine them into a single policy?

What is nearly certain is that the process of arriving at the tradeoffs will be hard. Nobel Prize Winner Kenneth Arrow formulated what would later come to be known as the Arrow Impossibility Theorem in 1950. "In voting systems, Arrow’s impossibility theorem, or Arrow’s paradox, demonstrates that no voting system based on ranked preferences can possibly meet a certain set of reasonable criteria when there are three or more options to choose from."

The need to aggregate preferences occurs in many different disciplines: in welfare economics, where one attempts to find an economic outcome which would be acceptable and stable; in decision making, where a person has to make a rational choice based on several criteria; and most naturally in voting systems, which are mechanisms for extracting a decision from a multitude of voters' preferences.

The framework for Arrow's theorem assumes that we need to extract a preference order on a given set of options (outcomes). Each individual in the society (or equivalently, each decision criterion) gives a particular order of preferences on the set of outcomes. We are searching for a preferential voting system, called a social welfare function, which transforms the set of preferences into a single global societal preference order.

Arrow's theorem says that if the decision-making body has at least two members and at least three options to decide among, then it is impossible to design a social welfare function that satisfies all these conditions at once.

So it turns out that it is hard to create a consensus of our acceptable tradeoffs even in principle. Which is why some wags have remarked that "the only voting method that isn't flawed is a dictatorship," which would suit the Greens just fine. So maybe we do need some nature "activists" like Frank Albrecht of the preceding post to simply tell us what Gaia thinks. And it seemed like buying a Green-friendly car was a simple task.