My Carbon Footprint

My Carbon Footprint: 365 days of tracking my CO2 emissions aka Self-Portrait: 365 Days of Considered Consumption  New England Institute of Art, Brookline Climate Week Brookline, MA, 2012.

Project Statement

Over the last few years, we’ve been poked and prodded from so many directions to consider our own impact on the global ecosystem, that we cannot ignore how our individual actions have consequences on everything – from our families in our own homes, to our neighbors down the street, to the local wildlife in the forests behind our houses, to birds dropping out of the skies, to all the fish in the sea, and even to unknown strangers in distant lands in places we’ve never heard of. Sometimes, upon listening to the news or reading the statistics, I just want to bury my head in the sand. The problem just seems too big for me to get my mind around.

I pay a lot of attention to environmental issues and I like to consider of myself as fairly eco conscious. Yet, when I read statistics that the U.S. per capita CO2 footprint is about 20 tons per year, I just don’t know what to do with that information. What is a ton of seemingly weightless, invisible CO2 gas and where does it come from? How do I get my mind around that?

Well, a ton – 2000 pounds – of CO2 would fill the volume of a 25.3′ cube or about twice the cubic space of my studio. A ton is the same as 50 of the 40-pound bags of pellets that I move off of my truck to heat my studio (yes, that’s a lot of lifting at once). So, for me, a way to think about it is that, if I produce 20 tons of CO2 per year, it’s like moving 1000 of my 40-pound pellet bags (which is 5 years’ worth of pellets). That’s almost 3 bags per day.

But, how do I create that much CO2 gas?
Sure, in our society, burning fossil fuels is the lifeblood of activity, but what does that mean on a personal scale. To answer this enormous question, and to understand my own CO2 footprint, I photographed everything that I did over one year that generates CO2. As I began to dig deeper into my activity, I realized that, basically, everything that I did somehow contributes to CO2 emissions. After all, my day doesn’t begin before I burp out CO2 – literally – then I make a cup of coffee with a stove burner using electricity that has a CO2 cost. Moreover, it doesn’t stop there: the coffee, milk and sugar each have a footprint and I probably drove to the store to buy them while spewing out CO2 from my car tailpipe. Everywhere I look, there is another layer to consider and calculate.

After one year, more than 28,000 photographs, hundreds of bills and receipts, untold spreadsheets and calculations, I am just beginning to understand my own CO2 footprint. This installation is a work-in-progress, as is my actual CO2 footprint of 18.95 tons. Both will undoubtedly evolve as I dig deeper.

Why care about my CO2 footprint?

Climate science and carbon emissions are very complicated subjects. As a layperson, it’s difficult to understand the complex science and geologic time scales while also separating our personal experience of weather from climate. But, I’m just old enough to have witnessed and remember real, observable changes in climate trends in my lifetime. Spring reliably arrives 10 days earlier than when I was a kid. The running of maple sap is no longer reliable or predictable. Flowers bloom earlier. My honeybees emerge from the hives sooner. I plant my garden two weeks earlier than I ever used to. And, winter comes in later.

It’s indisputable that carbon dioxide emissions from fossil fuels have changed our climate. In 200 years, we have burned our way from 275 ppm to nearly 392 ppm CO2 in the atmosphere. That’s led to 1.4 degrees Fahrenheit rise in global temperature in the last 120 years. That means melting polar ice caps, smaller winter ice shelves, raising sea levels, disappearing island nations, animal and plant migration northward, droughts, extreme weather, hotter summers, colder winters, mass species extinction, changes in tropical disease vectors as mosquitos expand into new latitudes… All this is merely a sample of what we are already experiencing now. Even if we miraculously slow our current rate CO2 emissions today, with just the CO2 that we have already released into the atmosphere, we can expect another 3.5-10.8 degrees Fahrenheit increase in global temperature change by the end of the century.

Yet, we continue to pump more CO2 into the air – at an accelerating pace.

The world will be a remarkably different place in less than 100 years. The maple trees that I tap in New Hampshire will be extinct. Heat and midsummer droughts will eliminate some crops from my garden, while I will be able to grow others more successfully if I irrigate. Sea level will reshape my coastline, likely to the point of making the very spit of land upon which I live just a bit too soggy to stay. The “once-in-a-hundred-years” catastrophes of floods, hurricanes and snowstorms will occur every season and overwhelm our already outdated infrastructure. What happens to the breadbasket of the nation, when the Midwest doesn’t see rain again? What happens to the Southwest when there isn’t anymore snowpack to irrigate the unnaturally verdant cities of the desserts? What happens to the millions of people that no longer have drinking water when the world’s glaciers melt by mid century? What happens when millions of people living along Asian coastlines become homeless?

While I will keep my ‘what happens’ speculation to myself, I feel compelled to share why I care about my CO2 footprint. At the same time, however, I struggle to try to make the best choices, to not get complacent or to indulge in overconsumption – but it is a struggle and many times there are not always low impact options. Sometimes something just needs to be done – a flight to California, driving my truck to Massachusetts, or even a medical procedure. The point isn’t that we need to eliminate our impact, to stop producing CO2 at all, but to bring down those personal and national numbers to something that the global ecosystem can handle without spiraling out of control. It means that each one of us has to be individually conscious. Yes, that means making some sacrifices. All of us.

I felt uncomfortable the other day when my sister excitedly described an SUV that she had just bought. When I asked about its gas mileage, she replied, “I don’t know.” I realize that she doesn’t understand the connection between lifestyle and climate change – so many of us don’t think about these issues and I understand why. It’s just too daunting. But, regrettably, the time has come where we can no longer afford to look away. As uncomfortable as it is, we need to collectively and individually look into our own lives because we are not talking about theoretical things happening way off into some intangible future in a foreign land anymore. We are talking about serious things that my own daughter will bear witness to firsthand.

My sister has daughters, too.


Calculating one’s CO2 footprint is a surprisingly complex task – there is the obvious direct impact of a given activity, but almost everything also has some indirect cost. There are many elements to consider as layers are peeled back. For example, if I bought groceries at the local store, there is: driving to the store; the cost of growing the food which includes fuel, fertilizer and pesticides; the packaging; the transportation of the products to the store, the utilities to keep food fresh; electricity for my own refrigerator; and finally, the disposal of the remaining packaging. Some details are nearly impossible to assess, but most importantly, how do I resolve the question of where my own CO2 footprint ends and someone else’s begins?

So, once I got into deciphering these multiple layers of my energy use, I realized that I needed to document virtually all that I did, as most everything somehow contributes to the big picture of my personal CO2 footprint. To do this, I primarily kept a photo diary of my activities, but also kept receipts, bills and notes to capture as much information as possible. While this documentation is about one year’s activity, I did include a two-month overlap, to gain some year-to-year comparison.

For this installation

I compiled the data and photos from the year, then analyzed one day of each month in minute detail. From there, I could extrapolate my one year CO2 footprint and cross check this against known year total values for such things as gallons of oil used, miles driven, kWh’s of electricity used, etc. For each of the fourteen months included in the analysis, I chose the same day of the month, the midpoint of the 15th, in order to provide as much accuracy to the method of averaging and to avoid the temptation to cherry pick the most interesting days.

After calculating the CO2 impacts of the various activities of each day, I generalized these into four impact categories to be represented by differently sized photographs. While not to scale, the differences in image size suggest the proportion of impact of each activity: largest (Air Travel), large (Heating), medium (Car Travel, Trash, Calories, Office Printing, Mail), small (Electricity, Water, Breathing, Telephone). The fourteen days are represented by over 1,250 images. The remaining 6,000 smallest size photographs that fill out the installation are not weighted for CO2 impact but document CO2 generating activity occurring on the 1st, 5th, 10th, 20th, 25th and 30th of each month.

While this analysis is far from perfect, it is a methodical approach to be consistent, accurate and honest. While many specific subcategories require considerable further analysis, this exhibit is the beginning of analysis. For, the purposes of this installation, supported averages values have been used where necessary.

Apples to apples?

Many of the online CO2 footprint calculators are too vague and broad to be useful in their specifics. This is somewhat illustrated in the range of 6 to twenty-four tons of my own footprint as calculated by some of the most popular online sites which can be seen in the included screen captures. I’ve come to realize that the number that I have generated for my own footprint is somewhat misleading as compared to these generalized numbers – it is comparing apples to oranges. I also believe that the US per capita footprint of 20 tons is a misleading and inaccurately low number. However, it is helpful to have a sense of what that these averages are. When I try to compare apples to apples using EPA methodology, my CO2 footprint seems to be about 9.36 tons vs. 20.3 per capita. Additionally, since my daily work life as an artist is included as a significant part of my analysis, my numbers are difficult to compare to another person’s that does not also include energy use while at work. For an office worker spending the day inside a climate-controlled building, where do those emissions get charged? For my postal carrier driving all over town, are those emissions hers or partially mine?


In many ways, much of the data available is comes from Europe, and the UK in particular. As a result, many calculations do not make sense for US-based analysis. For example, our food production system is entirely different and the use of UK-based would be erroneous. Additionally, in the US, there is little available data on the CO2 impact of food production and a lot of attention to the impact of food miles. Thus, most US calculations seem to rely on this data but ignore production – which then makes the comparison of US and UK numbers incompatible because they are looking at different things. Also, one must be diligent in converting metric numbers to American standard, in particular tonnes to tons. Some calculators have been discovered to improperly weight CO2 footprints due to these issues.


Breathing: the human body produces about 2.3 pounds CO2/day with 12-20 breaths/minute. For this calculation, I used average CO2/day and adjusted up for instances of vigorous exercise. Exercise breathing can increase to 40 breaths/minute and I estimated about twice the CO2 impact for exercise breathing (which may be slightly low). My CO2 generated from breathing is only included as a point of interest and for reference – this CO2 is not ordinarily considered as part of our CO2 footprints as this CO2 is considered part of the closed loop natural system in which plants use the CO2 to fix O2. Therefore, there is no reason to feel badly about breathing and I do not advocate stopping.

In these specific fourteen days examined, only one day contained includable exercise. This does raise questions both about the method of using averages for analysis with sporadic activities and my general fitness. Draw your own conclusions.

Calories/Food: estimates for food impact for the average American diet range from 2 to 6 tons/year depending upon the source. For my lacto-ovo vegetarian diet, estimates average about 1.15 tons/year. I weighted my impact slightly higher at 1.47 tons to accommodate the occasional animal product. For the purposes of this installation, I have used these averages only. Future analysis will include adjustments for daily variation in calorie consumption and breakdowns for levels of processing.

Electricity: this was measured by noting daily kWh’s used on each of three electric meters, referencing monthly utility bills and the observation of my use of appliances. Power requirements (watts) of each appliance have been take from equipment specifications or kil-o-watt meters. Estimates of appliance use (time) have been recorded by the time stamp of photos taken to document when I used the various appliances. New Hampshire has an unusually low CO2 emissions rate of .00834 lbs/kWh (compared to 2.24 lbs/kWh in North Dakota), which makes my electricity generated CO2 footprint surprisingly low. For my use of electricity, I generally documented only my direct use – i.e. when I turned on an appliance – however, for the purposes of my footprint, I have relied on meter reading to capture household use.

Heating: includes gallons of oil for hot water and space heating, therms of natural gas for my Button Factory studio, and pieces of wood for my home. While I include a category for wood pellets used to heat my barn studio, I have not found a satisfactory value for this fuel. Both wood and wood pellets are considered carbon neutral fuel sources as they derive from plants that up until recently actively removed CO2 from the atmosphere. In burning wood, that CO2 is just released back into the atmosphere to be taken up again by more trees and therefore is part of the closed loop. If the wood were to rot in the forest, it would still release the same amount of CO2, albeit more slowly. Especially for wood pellets, which are just compressed sawdust, it is a waste product coming from forestry slash or manufacturing rather than being harvested specifically as fuel. However, it does require some manufacturing to process, package and, ultimately transport to my house. So, in fairness, I believe wood pellets deserve some CO2 value, though possibly negligible compared to my fossil fuel use.

Calculating the cost of burning wood is especially complex to consider. First, manufacturing and transportation are negligible for cordwood, possibly only amounting to 40 lbs/cord by the time it arrives in my yard. Then, while burning wood releases 1.6 lbs CO2 for each pound of wood, that CO2 is technically carbon neutral. But, there are other things to consider: it takes an average newly planted tree 100 years to absorb 1 ton of CO2, seeming like a long time for that CO2 to linger. On the other hand, I’ve also read that, for each tree cut, another six take its place – so, it’s not just one tree taking up that CO2, at least initially. Therefore, in order to acknowledge both the slowness of that CO2 absorption and the consequence of fossil fuel use in harvesting my cordwood, I have elected to apply a 25% value to its CO2 emissions, not considering wood burning completely carbon neutral.

Heating oil and natural gas are easier to measure. Oil generates 22.377 lbs/gallon and gas 12.01 lbs/therm. Unlike most CO2 calculations, I did not divide my home heating by the number of occupants. Perhaps I should, but my initial thought was that I would be heating my home to the same level regardless of the number of people living there. So, the energy to heat my home represents an example of the total energy used to heat a home.

Mail/Shipping: for first class mail, the assumption is 1.10 lbs/piece of mail delivered. For packages delivered by truck CO2 emissions are .65 lbs/ton mile. For packages delivered by air CO2 emissions are 3.37lbs/ton mile.

Telephone: emissions are calculated based upon an estimate of .00056 lbs/call related to utility switching equipment and cell towers. This assumes .014 kWh’s/cell minute and an average of 5 minutes calls.

Transportation, Car/Truck: gasoline releases 19.6 lbs/gallon, diesel releases 22.4 lbs/gallon, and B50 biodiesel releases 14.11 lbs/gallon. This equates to 1.04 lbs/mile in my truck and .32 lbs/mile in my car at 45 mpg.

Transportation, Air: Flying is by far the largest single activity responsible for CO2 emissions. For long flights, I used .88 lbs/mile. This does not include an extra weighting to account for radiative forcing (RFI) – it would certainly be more accurate to include this, but since it is not commonly used in general calculations, I have opted not to at this time. A suggested RFI by the IPCC of 2.7 would raise air travels CO2 emissions significantly. In my case, .88 lbs/mile * 2.7 = 2.38 lbs/miles. This factor would raise the CO2 cost of my 2,668 mile flight to 6,339 lbs.

Trash: the EPA estimates CO2e emissions at .94 lbs per pound of landfilled trash and .62 lbs per pound of recycling. CO2 emissions result from decomposing garbage as well as energy used in hauling, burying or recycling.

Product Consumption: this category requires further research in order to calculate.


The Observer Effect.
The very act of observing a system, phenomenon, trend or habit alters the very outcome of the act.

  • Did the act of observing your own habits, change your behavior?
    Yes, by the vary nature of documenting my own habits, I began to alter those habits.
  • Do those changes compromise the integrity of your project?
    I don’t think the changes compromise the more scientific process of this project, My goal was not to do this work in a vacuum, but ultimately to learn about and modify my own habits. I took on this project with the idea of altering my behavior to reduce my personal impact. Moreover, understanding my own CO2 footprint to this level of depth and intricacy is extraordinarily complex. As it turns out, many of the insights I’ve gained have come more from the later analysis of the documentation and data rather than during the yearlong recording period.
  • Did you record & document everything?
    Yes, with minor exception. There are a few instances where I just forgot to make a note or take a photograph and there are some moments or data lost, but I sincerely attempted to be comprehensive. On several occasions, I dropped and broke my camera and was without the ability to record photographs until I was able to replace it.
  • What changes in have you made to reduce your CO2 footprint since you started this project?
    Almost immediately upon starting this documentation, I started to move away from using oil wherever possible. I started to heat my house with wood as the primary fuel. I switched my car from B10 (biodiesel) to B50-100 (depending upon the season). I replaced most of my light bulbs with compact fluorescents. I removed vampire electric appliances from ‘always on’ by unplugging or putting them on power strips. I started a very large garden from which I have been able to grow a significant amount of my family’s food. There are also less obvious acts, such as in making choices about purchasing products based on their manufacture, acquisition or use impacts. I began to reduce my air travel. After the year of documentation, I have continued to do some other significant things, such as: removing my oil furnace and installing a pellet boiler, installing a solar hot water system, installing a solar photo-voltaic electrical system, plus raising honeybees and chickens.
  • What’s the simplest change that you’ve made that has a big impact?
    I switched from making my morning coffee with a stovetop espresso maker, to using a cold brew system. I now make my coffee once a week and it doesn’t require any electricity to make.

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