Christopher X J. Jensen
Associate Professor, Pratt Institute

My ecological footprint for 2016-2017

Posted 31 Oct 2016 / 0

where-brooklyn-at2011-06-28-cropIt’s that time of year again. Once again I send my students in my Ecology course out to estimate their ecological footprints, so to show that I am holding myself to a similar standard — and to make sure to keep myself ecologically self-aware — I always make sure to make my own footprint public.

This should be an interesting footprint for me, because there have been some major lifestyle changes over the past six months. My family of four-and-a-half people (me, my wife, and our two younger kids plus their much-older half-sister, who is with us only half of the time… hence the half family member by footprint standards) have made a big change in housing since the last time that I did an analysis of my footprint. We moved from our Brooklyn co-op apartment, which was 1100 square feet in total, to a much larger Queens house of about 2100 square feet. It’s a row house, so in theory it should be pretty efficient with heat, but there’s no getting around the fact that we have doubled our floorspace. A big problem of living in a co-op is that it is hard to have direct agency over changes to infrastructure — and our co-op did not seem very energy efficient — so now we should at least be able to make our house more sustainable. But we just moved in, and finances are tight, so it’s not like we can have the place outfitted with solar panels and a special rainwater catchment system by next week… we are going to have to work up to making this house of ours into a sustainable paradise.

The house is the big lifestyle change, but of course it brings with it some other interesting changes. My bike commute went from 10.0 miles (16.0 km) to 17.6 miles (28.2 km) round-trip, so I am riding more miles to work. This might be increasing my food intake a bit! And because the public transportation route between Pratt and my new home neighborhood of Astoria is pretty circuitous, I likely will be taking the train a lot less. We might be driving our car a bit less because we now live in a more complete neighborhood. And we definitely are spending less on discretionary goods, because the house purchase has put us on a real austerity budget. This is just a continuation of a phenomenon that I have described before, which is that when you have two kids young enough not to be in the public schools system, you just have a lot less money to do things like fly on a plane or drive somewhere on vacation or buy new clothes. Having minimal discretionary income makes it a lot easier to be sustainable (after all, affluence is part of the IPAT equation!).

This year I asked my students to use a different footprint calculator because the one I used to use started charging $1 per day and although I think this is a reasonable charge I really couldn’t erect another boundary to their completion of this important task. So I went with the Global Footprint Network calculator, which will be the first that I will subject myself to. This calculator’s a funny one, but it seems to work pretty well. Like a lot of these online calculators, it starts off by asking you to specify a particular region. This is critical because different places have very different baseline impacts. There’s a little bit of diversity on the “global” network of this footprint calculator, but many places on the Earth won’t find themselves represented and the United States — in all its climatic diversity — is represented as a single, monolithic region.

I like Flash-based activities because they can be really dynamic in both what they display and where they can be used, but Flash also invites design distractions that don’t necessarily aid in the actual accomplishment of the tool’s goal. That’s my gripe with the GFN calculator: it has all sorts of features that are just distracting: weird background music, unnecessary objects dropping from the sky, and a personal avatar whose personhood doesn’t seem to have much value. But the interface is valuable when it comes to entering your lifestyle data: simple sliders can be used to provide a general estimate of one’s consumption or a more detailed accounting. This option to be more specific is great, because it allows the user to decide how much work he wants to put into making the estimate. With all ecological footprint estimators, there is always an accuracy/accessibility tradeoff.

I liked that for the food section I could clearly indicate that I don’t eat any meat or dairy/eggs. It was also valuable to think about how much of my food doesn’t come in processed form, and how much I get from local sources (which I believe is pretty low for me right now… we haven’t gotten into a rhythm with local farmer’s markets in our new neighborhood!).

For the consumption of other goods, it was a bit harder for me to make clear estimates. The categories, which include clothing, appliances, furniture, electronics, and other media consumption don’t really capture where we have both purchased a lot and disposed of a lot in the past 5 months: flooring, painting, and other construction materials. I tried to just overestimate our overall consumption patterns in an effort to compensate for the lack of direct questions that really capture our consumption patterns in the last year.

When it came to characterizing our house, again fit was a bit of a problem. The closest category was probably “Duplex or building with 2-4 housing units”, although this may be a bit too forgiving of our house. It is like a duplex in that it is attached on two whole sides to adjacent houses, but it is more like a “free standing house with running water” in that we occupy the whole house. To compensate for the possible under-estimation of my house’s true impact, I selected four rather than five people as our household size (not surprisingly, the “half-person option” was not offered). This should make my impact appear a bit larger than it actually is, because the per-capita impacts will be higher (divided by four) than they actually are (divided by four and a half).

The house details that one can get into are impressive. I was able to specify that I live in a brick house, that I get 100% of my electricity from wind power, and exactly how much I spend in electricity and gas (although if you are going to ask me about my bill, why not just ask me directly about the quantity of energy I use?). Because we have not lived through a full winter, I wasn’t able to fully estimate our actual heating expenses. For transportation, I wasn’t able to indicate that I ride my bike to work every day, but the effects of that bike riding were clear in just how few miles I had to enter for driving, public transportation, and driving in a car (these miles might have been a bit underestimated because I rarely use a car on a weekly basis but do accumulate some miles on a couple of family vacations per year).

All in all this was a pretty quick footprint calculator to complete. And here are my results:


Whoa, 3.5 earths, a big increase from my previous years! Although done with a different calculator, my totals from the past two years were 2.41 earths (2015-2016) and 2.56 earths (2014-2015). Is it possible that all this is due to changes in my housing situation? No longer living in a condition that we considered “on top of each other”, are we now dramatically less unsustainable?

As is always the case with these estimators, it is a bit hard to diagnose the full cause of one’s unsustainability. Clearly the amount of energy needed to power my lifestyle is the glaring part of my footprint in the report above. I like the concept of “energy land”, which I assume is land area needed to offset emissions from the energy that I use. And the other “needs for land” seem correct to me: a good amount for my food, but none for grazing or fishing because I am vegan, and a fair amount of forested land… although it’s not clear if that’s also an offset or if the calculator thinks that I consume a lot of wood.

When I looked at the categorical breakdown of my footprint, I was a bit surprised. I assumed that “shelter” would be my biggest category, but instead “services” was the overwhelming share of my impact. A bit befuddled by this categorization, I checked out the GFN frequently-asked-questions page. Here’s what it said about my “services”:


By my reading, this suggests that more than half my footprint is comprised of shared impacts that I don’t directly control. While this makes sense — we are, after all, responsible in some ways for everything done “on our behalf” by our government — it made me wonder if other footprint calculators make the same assumption.

So I went back and used the same calculator that I have been using for the last several years, the Center for Sustainable Economy’s (CSE) ecological footprinting tool. Like the GFN tool, the CSE tool starts off by asking you to identify you home country. Unlike the GFN tool, the CSE tool maintains many more regional options. It also begins with an interesting opening question: what’s your household income? Already there are big differences in how this calculator estimates impact.

Another level of detail that’s confidence-inspiring in the CSE tool is the fact that once it asks you your home country, it also asks you for your climate region. It’s nice to know that my footprint assessment won’t be the same as a person living in Southern California: clearly I require a lot more greenhouse gas emissions just to stay warm through my New York winters. It also asks for a lot more precise information: you must be able to estimate the number of miles you travel by all different means of transportation. Unlike the GFN tool, this probably pushed me to make a clearer estimate of my actual automobile travel, because it is a lot easier to estimate the total miles I traveled on a couple of vacations than to amortize all that mileage to a weekly estimate.

The details in the CSE footprint tool also extend to a variety of energy-saving habits, the kind of city or town you live in, whether you purchase organic foods, how frugal you are, and how much you use items until they are fully worn out. But I ran into the same problem in categorizing my new row house, which has the insulative character of a small apartment building despite being technically a single-family home. All of these calculators would be better if the idea of a row house — which is a very common urban home in the United States — was included in their menu of housing categories.

So with all these differences in the details of what I was asked, you would think that my CSE-estimated footprint would end up being somewhat different than my GFN-estimated footprint. But it was not!:


With all their differences in what they asked, both footprint calculators came up with about the same estimate of my impact. And they both agree: my shift to a larger house has some serious ecological consequences (almost a full earth’s worth!).

Here’s how the CSE-estimated footprint broke down my impacts:


For the first time ever, one of my impact categories exceeds the national average. My housing impact is a lot higher, and that makes some sense. I am living in nearly twice the square footage of my previous home, so not surprisingly the resulting fooprint is nearly double what I had in the past. This is a very sobering reality: housing energy costs account for such a major portion of our footprint that any increase in living area just boosts up one’s ecological footprint. At first I thought that this had to do with the operational impacts of our house. For a variety of reasons, we are going to have to get down to some serious energy efficiency improvements around this new house soon, and I am going to look into whether a solar-thermal water system might work here. The grim reality of “we heat our water and our house with natural gas, and there’s no true alternative” really sets in when you look at my mammoth increase in footprint this year. Or does it?

According to the CSE FAQ page, the housing footprint actually doesn’t have anything to do with energy at all. This footprint has to do with the land area the home takes up (which is tiny for our row house!), the forest area needed to provide the wood to construct the house and the watershed to supply the house with water, and the carbon footprint of the house’s construction. While it makes total sense that as the new homeowner of this nearly 100-year-old house I would be “charged” with some of this impact, that it would comprise my largest category of impact is a bit surprising. I know that new home construction is very environmentally impactful, but the house is really old. It’s hard to believe that my share of impact would end up being this high if the calculator took the details of my house’s history into account. But estimates based on national averages are a key feature of these calculators, and apparently one’s share of the construction costs of a home can be pretty impactful.

This does beg the question “why do these calculators come up with such different estimates of my energy impacts?”. My “carbon footprint” according to CSE is way lower than my “energy land” according to GFN. And there’s something else here that’s a bit disturbing: CSE says my lifestyle requires 133.79 global acres, whereas GFN says my lifestyle only requires 15.8 global acres. Either the acres don’t match between calculators or what they estimate as productive earth surface area differs by nearly a factor of ten, because it makes no sense that both calculators would suggest that my lifestyle requires three-and-a-half earths while producing such different estimates of my actual footprint area. Here’s where I wish these calculators were more transparent in their calculations, because I would really like to know what’s going on with this discrepancy.

While it is is great that both calculators agree on my overall footprint, what’s a little disconcerting is that the actual estimate of where my impacts accrue vary quite a bit between footprint calculators. Whereas the biggest chunk of my GFN-estimated footprint was in the general “services” category, the CSE-estimated footprint suggests that housing is my largest category of impact. The difference in how each calculator portrays my footprint almost makes me think that the quantitative similarity of their final estimate was just coincidental. I know all of these calculators use slightly different metrics, make different assumptions, and take different kinds of shortcuts in making their estimates. But that they have such different ideas of where my impacts occur is disconcerting.

What’s more unsettling is that the CSE calculator displays the following breakdown of my “areas of impact”:


Perhaps I am misinterpreting the meaning of this land and what it actually does, but unless the “pastureland” and “marine fisheries” areas are actually absorbing my greenhouse gas emissions (which they very well could be!), the size of these numbers makes no sense given that I am vegan and don’t eat meat from either land or sea. I have to imagine that the “carbon sink” use of these areas can be the only explanation of their magnitude.

I want in future years to track down a more detailed and transparent footprint calculator so that I can get a better estimate of my actual footprint. I should be keeping better records of my energy-c0nsuming activities such as driving and traveling by plane and rail. And I would like to find a calculator that takes better advantage of more specific information that I have in hand, particular the number of kilowatt hours of electricity and cubic meters of natural gas that my household consumes. Perhaps after the long winter I will take stock again to see if I can get a better estimate of my real footprint.

But here’s one thing I don’t question even as I struggle to interpret the differences between these footprints: my life is far from sustainable. This year my family made a decision that made our lifestyles even less sustainable. Over the coming years I hope to tinker with ways to lower the impact of living in our new home; I think that there are many energy efficiency steps that we could take, and I am also interested in the possibility of some sort of renewable-energy-based heating system. But I also think that these footprints always point out that changes to personal lifestyle alone will not be enough. We need a more sustainable country, which means changing energy policy in a way that forces us to move away from fossil fuels. If I want to reduce my ecological footprint, it’s as important that I lobby for a low-carbon economy as it is that I make changes to my own lifestyle.

A Major Post, Anthropogenic Change, Biodiversity Loss, Climate Change, Ecological Footprinting, Ecology Education, Environmental Justice, Ethics, Habitat Destruction, MSCI-270, Ecology, Pollution, Sustainability, Teaching Tools

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