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Our Carbon Footprint in the Archives

September 9, 2019
Morning commute in Los Angeles, December 2017

From the Papal encyclical Laudato Si, to the work of Fossil Free PC(USA) at the last General Assembly, to climate crisis activist Greta Thunberg sailing to New York, the costs and consequences of the global fossil-fuel economy continue to bear on our minds, and--though you may not have thought of it--on our work in the archives. From how and why we maintain paper-based texts, to how we contend with the after-effects of our digital life, a reckoning with the carbon costs of our work is due. Here, in broad strokes, is the carbon footprint of the National Archives of the Presbyterian Church (U.S.A.). 

Let's first talk about paper. Depending on a number of factors, and sources for these claims differ, the emissions cost to use a thousand sheets of paper as text for the life of the paper is between 5 and 8kg of CO2. We hold 34,000 cubic feet of archival material in our building, the bulk of which is text on paper, something to the tune of 90,000,000 pages. Taking the high-end carbon cost of 8kg per thousand pages, the archives as constituted cost about 720,000kg of CO2.  

The great thing about paper as a carrier of text is that once it's produced, it's relatively stable, and doesn't require additional energy to maintain. In common storage conditions, text on acid-free paper will persist for 500 years. So break that out and our 90 million pages amount to 1,440kg of CO2 per year, equivalent to the carbon footprint of one person driving to work over four months.

And so Princeton Theological Seminary's 1597 edition of Calvin's Institutes, which is about 1,000 pages, had a fixed carbon cost (arguably less than our current cost, and mostly to do with the number of trees felled and so no longer able to sequester carbon), and then spent most of the last 400 years in blessed tranquility, before landing in the Internet Archive:

The preservation copy of this text--full-size individual images in jpeg2000--is about 1GB in storage. If maintaining 1GB of content in internet-accessible storage costs somewhere between 0.2 and 7kWh (there are a lot of variables involved), let's say 3.5kWh/GB, and a kWh can be produced and transmitted on the US electrical grid at a carbon cost of 2.25kg of CO2, that one version of the Institutes runs to 7.87kg of CO2 per year. The total text in our holdings, if digitized and stored remotely, could then amount to an annual emission of more than 700,000kg of CO2.

So what does ballpark archival storage cost in carbon? A good archives space probably runs between 100,000 and 200,000 Btus per square foot per year to maintain its climate: we're chillier than an ordinary office building, but not as chilly as the refrigerated section of a supermarket. (The above link is a five-year-old source, and newer buildings will do even better.) Here are CO2 emissions per Btu burned by source; here a New York Times feature on energy mixes by state.

For example, Pennsylvania's mix is comprised of 22% coal and 34% gas. Some quick math (coal makes 90kg of CO2 per million Btus, which means 9kg per 100,000 times 0.22 [proportion of coal in my electricity mix]) shows that about 1.98kg of CO2 is emitted for each square foot of space per year. The gas portion of my mix (another 1.7kg of CO2 per square foot per year) shows me that a Pennsylvania archives will run between 4 and 6kg of CO2 per square foot per year. The PC(USA)'s storage space is about 10,000 square feet, so we’ll give off approximately 36,800kg of CO2 per year. To put that in context, the average US driver puts 4,600kg of CO2 into the air every year. So our archival storage produces about eight car’s worth of CO2.

PHS Archives Annex, where most archival materials are stored, 2019.

Despite having seen incremental changes occur in the past decade--not so long ago Pennsylvania's energy mix was more than 50% coal--the specter of consistently underestimating global heating haunts many archivists, and makes us reconsider our approaches to collecting and preserving material.

For enlightened thoughts on libraries and archives in the climate crisis, see Dying Well In The Anthropocene (2019) by Sam Winn and  Libraries, Sustainability and Degrowth (2016), by Edgardo Civallero & Sara Plaza.