Ecological Accounting

By Daniel Goleman and Gregory Norris (a version of this blog appeared as a New York Times OpEd on Sunday, April 19, 2009)

With spring in the air, our thoughts turn to outdoor pastimes, and increasingly these days, to ecological correctness. Consider, for example, that paragon of eco-virtue, the stainless steel water bottle that lets us hydrate without discarding endless plastic bottles. A fine-grained accounting of the ecological impacts of steel versus plastic reveals some surprising twists.

What we think of as “green” turns out to be less so (and sometimes more so) than we assume, when viewed through the lens of life cycle assessment or LCA, a method used by industrial ecologists – a discipline that blends industrial engineering and chemistry with environmental science and biology — to assess how manmade systems impact natural ones. LCAs yield a fine-grained analysis of the environmental and health impacts of a stainless steel bottle from the extraction or concoction of its ingredients and its manufacture, through distribution, use and final disposal.  

We’re all concerned about carbon footprints these days. But for stainless steel the main concerns in addition to climate change are releases into the environment of particulates and human toxins, depletion of fossil fuels and natural resources, and eco-toxicity.

 The 21st century has inherited from the 20th (and sometimes the 19th) a legacy of manufacturing processes and a palette of industrial chemicals that were developed in a more innocent age, when no one knew – or cared that much – about the impacts of industry on nature.  Today LCA, among other methods, makes these impacts vividly clear. This end of innocence presents a vast entrepreneurial opportunity: we need to re-invent everything, starting with the most basic methods of commerce and industry.

Many companies are already doing this. When Proctor & Gamble analyzed the energy footprint of all their products, the biggest villain was heating water for detergents – and so they developed a cold water alternative.

One avenue for speeding up such reinvention could be Earthster, a free, open-source, web-based program that offers business people LCA analysis of the various stages in a product’s supply chains. Earthster, now under development, will allow these industrial shoppers to signal their suppliers about the ecological improvements they want to see in products, and lets innovators tell potential buyers they have an upgrade to offer.

This process could set in motion a continuous easing of industry’s ecological impacts. Each product’s life cycle analysis can be read as a map for spotting where upgrades will do the most good. For enterprising inventors and entrepreneurs, every man-made thing represents opportunities to innovate to lessen impacts. For example, using a single wall rather than the double walls found in stainless steel thermos bottles uses 30 percent less steel, with proportional benefits in all the bottle’s ecological impacts. 

We can all help motivate these improvements by making such upgrades a business opportunity for innovation that pays. Newly available shopping software, called Goodguide, lets you roam the aisles of a store consulting your iPhone to get a comparison of Product A’s ecological impacts compared to five other brands of the same thing. Shoppers can choose any of hundreds of impacts as their lens on products, from carbon footprints or depletion of natural resources, to suspected carcinogens or other toxins. As we vote with our dollars on these issues, market share will shift to favor innovative eco-improvements.

Highlights from the Life Cycle Analysis of a Stainless Steel Water Bottle

1) Raw material extraction and processing: By some estimates there are over 1,400 discrete steps involved in producing stainless steel, like mining nickel and chromium ores, then heating the ore, and adding chemicals to concentrate and extract them. Each step can be analyzed for its environmental and health impacts. The largest are from processing the alloys used; food-grade stainless steel typically contains 18% chromium and eight to ten percent nickel, both in the form of alloys that readily mix with steel. Most chrome ore comes from mines in Kazakstan, South Africa, or India. Workers exposed to chromium have heightened risk of cancer. Production of high-carbon ferrochromium (a precursor to stainless steel) is energy intensive, and releases into the air carbon dioxide and particulates dangerous for respiration (for example, nitrogen oxide and sulfur dioxide) as well as toxins like the heavy metals lead, arsenic, and mercury that end up in air, water, and soil – partly from burning coal for electricity and then disposing of coal ash. Likewise, producing ferronickel draws on a supply chain that spews over 400 pollutants to air, water and soil, including barium, greenhouse gases – carbon dioxide and methane – and particulates.

2) Manufacture – at the steel mill: Steel can be made two ways: by melting and refining raw iron with an oxygen enhanced coal-burning furnace, or using electric arc furnaces to melt steel and iron scrap. In either case, making stainless steel is more polluting than making regular steel; environmental and health impacts are roughly ten times greater – largely because of the extra energy demanded by, and emissions from, producing the nickel and chromium alloys that make it “stainless”. Life cycle assessment lets steel-makers spot ways to lessen stainless’ ecological impacts, and to quantify the benefits. For instance, if the steel production used recycled iron scrap instead of newly mined pig iron, its impacts on human health and the environment would be 10-15 percent less; a single-wall design in addition to using recycled metals reduces the bottle’s ecological impacts by a total of about 36%.

3) Distribution – The bottle’s journey from factory to distribution center to you resulted in particulate and assorted other emissions, oil and energy use. If you bought it at a store,  heating and cooling, lighting, ventilation, heating, and all the materials needed to run the place can contribute as much environmental impact as producing the bottle itself. Shipping the bottle from Asia in a tightly packed cargo container, plus a few hundred miles by truck, add only one to five percent to the environmental burden.

4) Use. One danger of any reusable water bottle is bacteria build up. If you wash your stainless steel water bottle in a dishwasher that uses a half-liter of electrically heated water, somewhere between 50 and a hundred washes result in the same amount of pollution caused by making the bottle in the first place. If you wash it in cold water instead this still demands electricity to pump the water and chemical to treat it – but these impacts are tiny compared to those from making the bottle in the first place.

5) Disposal. Steel lasts forever; so disposal probably comes the day you lose the top. If you don’t replace the top, try to dispose of the bottle so that it finds its way to a steel recycler. By recycling stainless steel, you return not only steel but also the alloys of nickel and chromium, back into the production chain, reducing the need to mine and process these essential ingredients. The largest negative impact from throwing any steel into the garbage so it ends up in a landfill is the missed opportunity to recycle it. Some people object to the environmental cost of transporting recycled goods so they can be reprocessed. But the energy benefits and greenhouse gas reductions from using recycled steel to make a new bottle are more than ten times the energy required to ship its mass by rail freight from coast to coast.

The Bottom Line.  Stainless steel has virtues like being durable and hygienic makes it irreplaceable for, say, uses like surgical equipment. But is it always better than plastic as a water holder? If your steel water bottle takes the place of standard throwaway plastic ones, the steel alternative will become a net benefit to the environment somewhere between 15 to 25 uses for most impact categories. But this depends on the specific impact you care about; the tipping point is just eight uses for fossil fuel depletion, but near 500 for freshwater eco-toxicity.  Then again, there was a time before the advent of Perrier when we just used drinking fountains.

Bios: Daniel Goleman is the author of Ecological Intelligence: How Knowing the Hidden Impacts of What We Buy Can Change Everything. Gregory Norris teaches at the University of Arkansas and the Harvard School of Public Health, and heads the development of Earthster.

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