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Counting Carbon

October 6, 2009


Most of the debate about climate change focuses on carbon emissions. With the debate remaining front and center on the global political stage, companies are becoming increasingly concerned about their carbon footprint. As a result, counting carbon has become a growth industry even during this recession [“Hot Job: Calculating Products’ Pollution,” by Ana Campoy, Wall Street Journal, 1 September 2009].

“Concerns about greenhouse gases and other environmental hazards have spurred governments and companies to try to reduce the environmental impact of everything from auto fuels to water bottles. The first step in doing that is to assess the pollution those products impose on the Earth. Wal-Mart Stores Inc.’s most recent environmental effort — a bid to tag all of its products with information about their environmental impact — will force hundreds of its suppliers to inventory their pollution, which many expect will create a boom for the pollution-counting profession.”

Campoy reports that carbon counters use computer models to “process information about the energy and resources consumed by making, using and disposing of a product. At each stage, a product’s effects on the soil, water and air are tracked to come up with what is known as a life-cycle assessment.” Such assessments don’t come cheap. “Calculating the life-cycle impact of a single product can cost hundreds of thousands of dollars.” Although the process sounds straight forward, it’s not.

“The first step in doing a life-cycle assessment is collecting data on the environmental impact of the different processes involved, from extracting raw materials to transforming them in a factory. Sometimes that means measuring emissions from a smokestack or a tailpipe, but the statistical information often comes from databases compiled by companies like PE International. Most serious counters abide by guidelines from the Geneva-based International Organization for Standardization. It is up to the assessor to determine precisely what in a product’s production to count and what to leave out. But no clear rules govern the assessments, whose conclusions can vary sharply. While several organizations are trying to come up with standards, they don’t agree, and there are no enforcement mechanisms. There is also nothing to stop companies from looking around for a pollution assessment that will favor their products or points of view.”

The reason that there are no clear rules is because “the math is fraught with complexity and imprecision” [“Hate Calculus? Try Counting Cow Carbon,” by Jeffrey Ball, Wall Street Journal, 18 September 2009]. Ball writes:

“All the decimal points in the world can’t hide the fact that measuring carbon footprints is inexact. It is clouded by varying methodologies and definitions — not to mention guesses. ‘There are no clear rules for the time being,’ says Klaus Radunsky, who co-chairs a group within the Geneva-based International Organization for Standardization that is producing a guideline for measuring products’ environmental impacts. ‘It depends very much on how you do the calculations.’ Few products demonstrate the messiness of this effort more than a simple carton of milk. Several studies in various countries have already sought to tally the impact of milk from its production on a farm to the disposal of its carton. In between, the studies try to measure such intricacies as the energy used to make the fertilizer to grow feed for the cows, to fuel trucks delivering the milk, and to power refrigerators cooling it in kitchens. It isn’t surprising that each of these studies sizes milk’s footprint differently, in large part because each varies in the way it counts one or more of those factors. Milk is among the first products that Wal-Mart Stores Inc. is trying to measure as part of a broad effort by the retailer to assess the environmental impact of the products its sells. It intends to begin labeling certain products with a ‘sustainability’ score — a single number that would take into account not only carbon emissions, but also water use and waste production. That is doubly complicated because it involves weighing the relative importance of different kinds of environmental impact. Which is worse: that a tomato uses lots of water or lots of pesticide?”

If the math is complex and the results so variable, you can imagine that it is also difficult to provide a cumulative score that makes sense to consumers.

“Wal-Mart is working with academics and environmentalists to decide both how to tally that score and how to display it. It might be a number from 1 to 10, and it might be a color in a range of hues, says Matt Kistler, the retailer’s senior vice president of sustainability. The challenge is to come up with something that is understandable and accurate. ‘Can we get there overnight? No, because a lot of the information doesn’t exist yet,’ he says. ‘But I think we can get there.’ Among the reasons driving the measurement efforts by manufacturers and retailers are concern for the planet, marketing, to reduce emissions and, in some cases, to avoid being caught flat-footed by any coming climate-change regulation.”

Probably the most important value of the calculations, however accurate or inaccurate they are, is providing manufacturers with a clearer picture of where they can make the biggest impact in their efforts to reduce their carbon footprint. Campoy reports, for example, that “New Balance, a Boston-based maker of sneakers and athletic clothing, … found … that the materials that go into the shoes, rather than the trip from overseas, take the bigger toll on the environment.” I still suspect that measuring the carbon footprint of transporting many products will eventually encourage more regionalization of production. Ball explains why getting exact calculations are so difficult. He once again uses his milk example.

“[There are a] dizzying [number of] variables in the carbon calculation. Some farms have more energy-efficient machinery. Some cows eat less corn, which typically is grown with petroleum-based fertilizers. And some kinds of feed cause cows to burp more methane, a potent source of carbon. That bovine belching is widely agreed to be the biggest source of carbon emissions in milk production. But some parts of the equation are subjective. Cows produce multiple sellable goods: milk while they are alive, and, once they are slaughtered, products including beef, leather and bones. So how much of the emissions from the dairy farm should be blamed on the milk, and how much on the making of the steak and shoes?”

Tesco, a British supermarket chain, “attempts to resolve that question by splitting the emissions according to the relative economic value of the milk versus the cow’s carcass. If, say, a dairy farm got 90% of its revenue from selling milk and 10% from selling the cow, then 90% of its emissions would be ascribed to the milk and 10% to the other products.” The International Organization for Standardization, however, prefers a different approach.

“It seeks essentially to look inside the cow, separating the portion of the animal’s biological functions that go to producing milk from the portion that go to producing the cow itself. Those functions include the cow’s eating, burping, flatulence and waste.”

Frankly, neither approach is perfect. A perfect approach probably doesn’t exist. The important thing is that people will eventually begin to understand how the products they use impact the planet. Hopefully, it will lead to more recycling and better stewardship of the planet’s resources. Even people who continue to deny the existence of global warming or its causes should be able to embrace those goals.

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