Life-Cycle Assessment
My degree is in sustainability, and I would like to share the most valuable concept I learned through my years of studying at The University Of North Carolina’s Institute for the Environment. It is a tool actually, and its called a Life-Cycle Assessment or LCA for short. It’s a simple tool on the surface; you track the costs and impacts associated with doing something. It was designed for risk management, and is also known as a life-cycle analysis, cradle-to-grave, ecobalance and probably a few other things. You can apply an LCA to just about anything. While I will tie this back into Landscape Design and garden construction in the Brooklyn in the second half of the article, I will begin by explaining the concept and the process in more detail. (Image Credit: Solid Works)
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It is easy to explain how the LCA works with a basic product like a t-shirt.
You start with the individual components used to make the shirt. For simplicity, let’s assume this t-shirt is 100% cotton. So you begin by asking: what are the costs associated with growing the 1lb of cotton necessary to manufacture the shirt? You research and track down the efficiencies of the cotton industry, how much fertilizer, water, fuel costs for farm equipment, operational costs for the farm… It quickly gets complicated, and depending on how thorough your LCA is, it can go very, very deep. Farmers keep close track of their operational costs as farming is a business that depends on marginal profits and extreme efficiency. You might be able to find data on how much oil and diesel fuel the average cotton farmer needs to farm her land, and then figure out those costs per acre, and then costs per pound of cotton. After the first step, you end up with a few numbers, how much seed, water, diesel, oil, fertilizer and pesticides went into producing 1 lb of cotton for your t-shirt. Next it has to be shipped to the facility that spins raw cotton into cotton thread. Packing and shipping costs usually translate to more diesel fuel. Also, there are costs associated with running the cotton spinning mill. Then the cotton thread is shipped to a textile mill that makes fabric. Then it is probably shipped to a t-shirt making factory. More diesel.
There are probably more steps than you might think to get the t-shirt on the shelf, but in the end, it costs $15, and you are probably covering all the costs incurred along the way to make the shirt.
But are you really covering all the costs? What a detailed LCA reveals is that along the way in most processes, costs are externalized, usually on the environment. Let’s say that in the end, your t-shirt required among other things 20 gallons of water, 2 gallons of diesel and 10 grams of pesticides. The cotton farm creates fertilizer and pesticide-rich runoff which spurred algal blooms in a nearby pond. The pond went hypoxic and all the fish died. Nobody is paying for that besides the birds that ate those fish. Burning 2 gallons of diesel to produce and transport the cotton is paid for in the costs of the shirt, but what about the CO2 released into the atmosphere, nobody is paying for that. These are some of the costs of manufacturing the t-shirt that are externalized on the environment.
The LCA does not stop here, because next, the t-shirt has a useful life. How many times will the shirt be washed? How much water, detergent and electricity does that take? Lastly, at the end of its useful life, will it be thrown into a landfill or incinerated?
An LCA tracks the true impact something has during the entire life-cycle of the good, product or service.
Now imagine applying an LCA to something like a car. The base materials are steel, aluminum, plastic, rubber, glass, etc. A car has a complicated manufacturing process, with many raw materials, shipping, and milling processes. A car is also much different than a t-shirt because of its intended use. A t-shirt is produced, worn and washed, worn and washed, then thrown away or turned into a rag. A car is produced and then driven, maybe 200,000 miles before the end of its useful life. To complete an LCA on a car, you have to figure out how much gas, how many sets of tires, batteries, brake pads, oil, oil filters, windshields, windshield wiper blades, the car will require during its useful life. Cars are notorious for having externalized costs on the environment. At the end of the cars useful life, what happens to the components? Is the metal recycled, does some of it take up landfill space, how much energy does that take?
An LCA can be as simple or as complicated as one wants to make it. It is a powerful tool.
If you read through my first post on this blog, you might start to understand in a bit more detail some of my frustrations with claims of ‘green-ness.’ Where green is the talk of the town, it lacks metrics. It is so easy to throw it around. Now when you look at the LCA process, and how much work could go into limiting life-cycle impacts, it is no wonder that most companies choose to just call themselves green. How ‘green’ are some of the things we take for granted as being ‘green’ and good? I once did a thorough LCA on solar panels and was very surprised. In short, most solar panels require rare metals that are usually mined in China in less than ‘green’ ways. (Unless by ‘green’ you mean green rivers.) Human rights violations for health and toxic exposure are the norm. Producing the panels is energy intensive, it currently takes 7 years of full capacity energy generation for an individual panel to offset the energy required to manufacture the panel! Shipping, packaging, installation, glass housings, all for a useful life expectancy of 20 years. Then, disposing of old solar panels adds to the growing environmental catastrophe that is toxic e-waste. In LEED building, you get a whole bunch of points and street credibility for installing solar panels. Now, of course, solar panels are always getting more and more efficient, lasting longer, and even getting cheaper, so maybe in the future they won’t be creating such a bleak reality for impoverished workers in rural China, or maybe the situation will get worse for them? There is a research and advocacy group called the Silicon Valley Toxics Coalition that “promotes safe environmental practice in the high tech industry.” If you want to read more about the down side of solar panels, they are the experts. The point however, is that an LCA reveals the true costs associated with doing anything, including building ‘green.’
From Life-Cycle Assessment to Life-Cycle Building
LCA is an important concept that I would like to see in greater use in the building industry, including in Landscape Design in Brooklyn and Manhattan! I think many people, for all of history, have intuitively built with the LCA in mind, without necessarily having defined it as their ‘green’ building metric of choice.
Life-cycle building is building in a manner that takes the entire life-cycle of a building into account, from site selection and building materials acquisition to end-of-life disposal. In its simplest form, life-cycle building is asking and addressing three questions:
Where are the building materials coming from?
What is the intended function of the building?
What happens to the building at the end of its useful life?
Asking and thoroughly answering these questions is an easy method of starting a life-cycle assessment on any building or construction project. You must then figure out the environmental impacts associated with these three questions. A Life-cycle assessment generally measures actual environmental impact in a figure known as the total embodied energy. If you thoroughly measure the actual environmental impacts of a building’s life-cycle, and develop practices that balance these impacts, then you are offsetting the total embodied energy of the building. An environmentally sustainable building would balance its total embodied energy and likely offer positive social and environmental outcomes through the intended use of the building. It is unclear to me how many LEED points you might get for that? Lets say 3.
While these three questions are easy to remember, and to ask, there are a couple of complicated parts of this process. First, how does one accurately measure the actual impacts of a building’s life-cycle? Next, how does one develop practices that balance these impacts? The reason these two questions are difficult to answer is because of their implications. If you can honestly answer these two questions you have figured out how to build in an environmentally and a socially sustainable way, in the most strict sense of the terms.
Yes, true sustainability includes consideration for social impacts. LCA is a tool designed for environmental consideration, and sadly, most LCA’s do not include social impacts. In doing an in depth LCA, you should include social impacts. I would suggest that if your intention is to build sustainably, you remember that sustainability is as much a social condition as it is an environmental consideration.
A sustainable building project would balance its total embodied energy, internalize all negative externalities, and achieve positive social and environmental outcomes. If you figure out how to pull that off, do us all a favor and don’t call it green.
Internalizing Negative Externalities
The goal of applying the LCA is to discover the true cost of doing business. Capitalism has for too long reflected inflated profits stemming from externalized costs on the environment. The natural world does not, and in fact CAN NOT externalize costs. On an ecological level, Newton’s Third Law of Motion applies. We need to remember that our actions are a part of the natural world, and we must stop pretending that we can externalize any costs of doing business.
Internalize negative externalities, and adjust pricing to reflect true costs. Seek market shares of customers that value sustainable services and products. True sustainability creates long-term value. Customers, partners, investors, government policies and capitalism itself must adapt to valuing sustainability as more than a green facade. These are some of the values that I put forth with the work we are doing at Natural Garden Landscape Design & Build. This is why our projects cost more, and this is why you can rest easy knowing that your NYC garden is not degrading the Amazon Rain forest or polluting NYC watersheds. More on that to come.