By | December 17, 2007 | archive, textbook

The environmentalism movement is currently experiencing an injection of perhaps well-needed popularity. Celebrities who own multiple homes that could each comfortably house the inhabitants of small villages, and who regularly circumnavigate the globe in private jets that have a maximum capacity of seven, routinely remind us to do such environmentally responsible things as turn the lights off when leaving a room lest we become wasteful. Manufacturers of products ranging from toilet cleaners to sport utility vehicles advertise their wares as being earth- friendly by arbitrarily adding prefixes like “eco”, “bio”, or “green” to product names in hopes of capitalizing on our environmentally conscious sensibilities and thereby gaining greater market share. Most recently, with the awarding of the 2007 Nobel peace prize to An Inconvenient Truth filmmaker Al Gore and the Intergovernmental Panel on Climate Change, global warming has taken centre stage as the potentially catastrophic side effect of our carbon-emitting actions. Scientific consensus has widely established that mankind is changing the planet, and that, by every metric by which the sustainability of life on Earth can be quantified, this change is decidedly not good.

So, it is encouraging to see such widespread dissemination of our negative impact on the environment not only in the scientific community but also in mainstream popular culture and industry, even if the motives and sincerity of the messengers are sometimes dubious. As a species, it seems that we have generally begun to acknowledge the consequences of our actions. The next step, of course, is to establish a strategy for reducing this negative impact, and most people would agree that even if we have not yet satisfactorily implemented this strategy, we have a pretty good idea of what needs to be done.

To most of us, “what needs to be done” can be summarized with the “three Rs” of environmentalism: reduce, reuse, and recycle. The phrase “chuck it in the garbage” certainly does not find itself welcome in this list of earth-friendly Rs (even if we ignore the fact that it is not compatible with the established alliteration). The very word “garbage” conjures images of massive landfills teeming with used styrofoam cups, torn plastic bags, rusting metal parts, and other manmade refuse that is distinctly at odds with the pristine beauty that we associate with our natural environment. Intuitively, it makes sense to us that throwing things in the garbage is not an environmentally sound option. If asked to place the available options for dealing with a consumable product in order of their impact on the environment, I think most of us would probably say that the worst thing one can do is to throw a product in the garbage, that it is better to throw that product into the recycling bin, that it is better still to reuse that product, and that the best option is to not have to use the product at all. Until not too long ago, this order had always made sense to me. Perhaps it was my penchant for playing devil’s advocate combined with the recently renewed global interest in environmentalism, but for some reason I found myself questioning the scientific validity of this conventional wisdom one day when buying a cup of coffee from one of the many fine UBC campus coffee shops. At this shop, I was informed that I would be charged a little bit less if I supplied my own coffee mug. In addition to the obvious financial reward, this discount was presumably being offered as an incentive to lessen my negative environmental impact by cutting down on the amount of consumable materials that I use. Implicit in this logic, of course, is the assumption that by drinking from a reusable coffee receptacle, I am inflicting less harm on my planet’s ecosystem than I would by using a paper cup. With a background in engineering, though, I have been indoctrinated with the pragmatic (and maybe pessimistic) notion that there is no such thing as a free lunch – that is, if you manage to improve a process or product in some way, you inevitably pay for it by worsening it in another way. With this in mind I tried to roughly gauge the environmental impact of each of the available coffee handling options in the context of the aforementioned three Rs.

Consistent with my perceived order of the three Rs, the most environmentally desirable coffee receptacle is no receptacle at all. Ideally, coffee shop patrons would line up in front of coffee dispensers, open wide, and have their choices of tall, grande, or venti volumes of coffee poured directly into their waiting mouths. If we ignore the fact that the used bandages incurred from the subsequent medical treatment of throats scalded by boiling coffee might offset the environmental gains of this option, it seems obvious that of the three Rs, “reduce” is indisputably the most environmentally friendly choice. The most effective way of reducing the negative environmental impact of a product is to eliminate the use of that product altogether. Unfortunately, at least for consumers of hot beverages, this is rarely a realistic option. So I went on to consider the remaining options. The option encouraged by the coffee shop I visited was to opt for the second of the three Rs and to drink from a reusable mug. The option discouraged by the coffee shop was to opt for the third of the Rs and to use, and of course then recycle, a paper cup. The final option, and one that responsible coffee drinkers would never consider, is to simply throw the cup into the garbage after use.

The first things that come to mind when comparing these options are the most obvious benefits of each. Conventional wisdom dictates that reusing a mug is optimal because it obviates the need for another cup the next time I want to enjoy a coffee. If I must use a paper cup, recycling it eliminates the need to extract and process the raw materials required to manufacture my next paper cup and also eliminates the waste that would result from a disposable cup. Finally, throwing the cup in the garbage seems to have no discernible benefits. A new cup must be made from scratch for my next coffee purchase and the cup that I have used sullies my environment by sitting in a landfill somewhere. However, when attempting to make a more complete assessment and comparison of these options, a multitude of questions arose in my mind. For example:

- When reusing a coffee mug, most people find it necessary to wash it and, in doing so, consume some water and soap. Which has a more detrimental effect on the environment: the soap use and water consumption required to wash a mug or the solid waste introduced into the environment by disposing paper cups in a landfill?

- If one of these is worse than the other, exactly how much worse is it? For example, how many grams of soap released into the water system will cause an amount of environmental damage equivalent to that resulting from one gram of paper in a landfill?
- What pollutants must be released into the environment in the process of recycling a paper cup and what is the effect of these pollutants relative to the ones mentioned above?

- What pollutants are involved in the manufacturing of, say, a ceramic mug? Are they more or less detrimental than the pollutants released during the manufacturing or recycling of a paper cup? How much more or less?

- How much energy is expended in the process of making one ceramic mug? How does this compare with the energy used to make a single paper cup?

- How far is a ceramic mug transported from the factory where it is manufactured to the store that I buy it from? How does this distance compare with the distance that a paper cup is transported in order to get to the nearest landfill or recycling facility?

- How does the environmental damage of the carbon emissions resulting from this transportation compare with the pollutants mentioned above?

This to me, was already a dizzying array of questions, but one could go even further and ask questions that relate not only to the activities involved with reuse, recycling, and disposal, but also to the development of the infrastructure necessary for these options. For instance:

- What are the processes and resulting pollutants used in the construction of a factory that produces ceramic mugs, a factory that produces paper cups, and a paper recycling facility? How do these processes and pollutants compare to one another?

- What pollutants are released during manufacturing of the dish soap that is typically used to wash a ceramic mug, and how do these compare with all the pollutants mentioned above?

- How many people are required to run a factory which manufactures ceramic mugs and how many are required to run a recycling facility? If these employees all have to drive to work, how do these carbon emissions contribute to the environmental impact of each option?

Many of these questions do not seem relevant when first attempting to assess the environmental impact of each option, but answering all of them struck me as being essential in order to accurately compare them. It seemed to me that in order to conclusively determine that one option is more environmentally friendly than another, one would need to first take into account the environmental impact of all of the processes and by-products necessary for the execution of each option, and then establish some kind of common basis or standard with which to make an “apples to apples” comparison of the impacts of each.

A technique known as life cycle analysis (LCA) attempts to do exactly this. LCA seeks to consider the entire “life cycle” of a given product beginning with the extraction of the raw materials needed to create the product and ending with the return of all materials back to the earth. It then seeks to evaluate and compare the cumulative environmental impact resulting from all stages of the life cycle of different products. The ultimate objective of LCA is to guide the choices made by consumers, industry workers, or government policy makers in order to minimize the negative environmental impact of their actions. Unfortunately, although LCA is currently the most formalized methodology for performing such comparisons, it is also widely acknowledged as having fundamental problems that have already been highlighted by some of the questions asked above.

In order to make a comparison of multiple products or processes, the scope and boundaries within which to perform the analysis must be established. This is the first step in performing an LCA. The beginning and end of the life cycles of the products being considered are defined and different products are compared using some logical basis. For example, when comparing incandescent and fluorescent light bulbs, a logical basis for comparison is the number of hours they can provide light for. Using this basis, if a fluorescent bulb lasts ten times as long as an incandescent bulb, then ten incandescent bulbs should be compared against one fluorescent bulb. However, for products that do not have a well-defined lifetime, establishing such a basis for comparison is much more challenging. In our coffee cup comparison, how many paper cups should we assume can be substituted with a single ceramic mug? The ability to recycle a product also brings into question how the end of its lifecycle should be defined. For materials that can theoretically be recycled almost indefinitely, should their lifecycles be considered infinite? The beginning of a product’s lifecycle can be equally as dubious. Should the lifecycle of a product also include the construction of facilities that are needed for the manufacturing of the product? For example, perhaps, during the construction of a piece of equipment used in the production of ceramic mugs, a particularly harmful chemical is required. Neglecting this could erroneously make ceramic mug use seem more desirable than it actually is. These questions all make the definition of the scope and basis of this kind of comparison highly complex.

The next step in an LCA is to take a quantitative inventory of all of the energy, raw materials, airborne pollutants, waterborne pollutants, and solid waste that are consumed or produced during the entire life cycle of a product or process. This process is fairly straightforward assuming that a scope and basis that allows for a satisfactory comparison of multiple options has previously been established. However, depending on the established scope, this step could require the collection of an incredibly large amount of data. As well, companies that manufacture the products being analyzed will be understandably reluctant to relinquish data that could be used to conclude that their product is less environmentally friendly than that of a competitor.

The last step of a LCA consists of interpreting the data collected for each of the options being analyzed in order to assess the environmental impact of each. In this step lies the key weakness of LCA. While the cataloguing of the consumption and emission of a product or process can be scientifically rigorous, the interpretation and comparison of their environmental impacts can not be. Judgments without any purely scientific basis, such as whether a gram of dish soap released into the water system is more or less detrimental to the environment than several tons of paper waste disposed of in a landfill, are necessarily subjective to a certain degree. Are solid pollutants more or less harmful than airborne or waterborne pollutants? Is excessive energy use more or less of a concern than excessive water use? If one pollutant is known to primarily affect one species and another pollutant is known to affect a second species, do we choose which pollutant is less desirable by determining which species is more valuable? How should the consumption of non-renewable resources like oil be weighted against the consumption of renewable resources like lumber? The complexity and diversity of earth’s natural ecosystems do not allow for easily determined scientific answers to these questions and therefore do not permit different types of environmental impacts to be objectively compared and contrasted. There are differing approaches to dealing with this problem in the context of LCA. Some approaches attempt to demarcate various environmental impacts into clearly defined categories. So, for example, one might attempt to quantify a product’s contribution to global warming or its effect on the ozone layer relative to another product. But even if this quantification is accurate, it only leads us to question which aspect of the environment deserves more of our attention. Would we rather experience increased worldwide temperatures or increased exposure to high frequency ultraviolet radiation? Other approaches go even further and attempt to assign an overall environmental “score” or “rating” for a particular product. Some have suggested methods of arriving at a universal basis of comparison by attempting to determine and then compare the economic cost or the amount of energy that must be spent in order to avoid various forms of environmental impact. However, these conversions are hardly objective and scientific. The failure of all of these approaches is highlighted by the fact that many LCAs using different comparison methodologies have reached different and sometimes contradictory conclusions about identical products.

Despite these inabilities, however, LCA can offer benefits. It can help a company identify and improve steps in its engineering or manufacturing processes that are particularly harmful to the environment. LCA can also serve to provide data to the public with which decisions can be made based on regional circumstances or interests. For example, an LCA could result in the conclusion that a recycling program is not environmentally favorable for a relatively isolated city where transportation of materials to distant recycling facilities incurs high levels of carbon emission, but is favorable for cities that have such facilities in close proximity. Communities that are located close to natural waterways could impose the constraint that waterborne pollutants are of paramount concern, and in this way simplify the prioritization of pollution reduction.

I believe our inability to objectively compare multiple forms of environmental impact poses a serious problem to the scientific basis of the environmental movement. Without a standard by which we can measure, quantify, and contrast the ecological effects of various manmade processes or products, it seems impossible to determine which course of action is most environmentally desirable given an array of options. And this, unfortunately, is the environmentally conscious citizen’s central task.

I still feel that my perceived order of the three Rs is correct and that it is indeed better to reuse than to recycle or dispose. Intuitively, it still makes sense to me that drinking from a reusable mug and washing it when I’m finished is more environmentally responsible than drinking from a disposable cup and throwing it in the garbage. However, science has shown time and time again that human intuition is incorrect about a great many things. Given the seemingly infinite number of variables inherent in our natural environment, it seems highly unlikely that we will ever be able to objectively compare different forms of environmental damage with complete accuracy but perhaps more communication and collaboration between the scientists that study the condition of ecosystems and those that develop the industrial processes that supply us with goods and services will enable us to better understand our cumulative effect on the natural environment and thus come closer to this goal. Maybe this in turn will allow us to determine, at least with a little more certainty, whether that coffee shop was justified in making me feel bad for not having a mug with me that day.

About Kaston Leung

Kaston Leung is a graduate student in the Department of Electrical and Computer Engineering at the University of British Columbia currently doing his best to masquerade as a biologist. He dreams of one day formulating a satisfactory scientific explanation that will elucidate the mechanism by which Megatron is able to become so much bigger when transforming from a gun into a robot. When not busy trying to build microfluidic systems to solve biological problems, he enjoys eating bacon, drumming in Latin rock cover bands, and wishes that UBC was located in Whistler.