Electronic textbooks, often lauded as a cheaper alternative to hard copies, may also seem like a perfect way for colleges to reduce their greenhouse-gas emissions. Many institutions encourage use of e-books, and one state, California, has required that all textbooks used in college classes be made available electronically by 2020. In a sign of growing campus interest in cutting carbon emissions, nearly 700 institutions have signed the American College & University Presidents’ Climate Commitment, pledging to reduce their footprint and to promote education and research on climate change.
On the surface, this transition to digital media makes perfect sense: After all, purchased materials of all kinds make up a quarter of most colleges’ carbon footprints, and textbooks (in hard-copy form) represent about a quarter of emissions from purchased materials.
However, the reality is not so simple. E-textbooks require electricity to operate, and if students print out many pages from them, the resulting carbon footprint may actually be greater than that of the hard-copy textbooks they are replacing.
With so much uncertainty, we set out to answer the question: Which is more climate friendly—hard-copy textbooks or e-textbooks? We compared the greenhouse-gas emissions of both throughout their life cycles, including creation, distribution, student usage, and disposal, using existing emissions-related data and the results of a survey we conducted of 200 students in six undergraduate classes.
Our findings might surprise you. We discovered that when we consider all greenhouse-gas emissions over the life cycle of the textbook, from raw-material production to disposal or reuse, the differences between the two types of textbooks are actually quite small. Measured in pounds of carbon-dioxide equivalent (CO2e), a common unit used to measure greenhouse-gas emissions, the use of a traditional textbook resulted in approximately 9.0 pounds of CO2e per student per course, versus 7.8 pounds of CO2e for an e-textbook.
More importantly, we discovered that the ways that hard-copy and digital textbooks are used have a huge effect on emissions. Colleges that are serious about reducing their carbon footprint, then, should realize that the behavior of students, faculty members, and administrators plays a crucial role.
Most emissions from traditional textbooks come from manufacturing and distribution, adding up to about 12.8 pounds of CO2e per book. However, any subsequent reuse (for example, selling a hard copy to a used bookstore) spreads this burden, thus reducing emissions by about half, per copy, per semester, for a textbook that is reused two times. A hard copy that is resold four times reduces emissions per individual user by 80 percent. Approximately 78 percent of the students we surveyed said they resold their hard copies at the end of the semester. At the end of a book’s life, reuse also reduces the effective greenhouse-gas emissions related to landfill or incineration.
Reuse is by far the most effective way to reduce greenhouse-gas emissions associated with traditional textbook use. However, reuse is only partially under students’ control. Faculty members and administrators can encourage the practice by standardizing textbook choices across multisection classes and spreading out course offerings over the academic year (for example, offering sections of a class in the fall and spring as opposed to offering two sections only in the fall).
The behavior of students, faculty members, and administrators is hugely influential, meanwhile, in determining the greenhouse-gas footprint of e-textbooks, which is affected by two critical factors: electricity consumption and printing practices. On average, emissions from online reading account for more than two-thirds of the total e-textbook footprint. But there is a lot of variability. The amount of electricity consumed by e-textbook users depends on what devices they use to do online coursework or reading. Low-wattage systems such as laptop computers use four to five times less electricity than older desktop systems. Dedicated e-readers like the Amazon Kindle or Apple iPad use even less electricity than the laptop systems.
Some 76 percent of e-textbook users we surveyed did their online work and reading using a laptop. Using the U.S. average for greenhouse-gas emissions per kilowatt hour of electricity generated, 50 hours of reading using a typical desktop system results in nearly five times the emissions of a laptop and more than 18 times that of a dedicated e-reader. Encouraging migration to laptops and other mobile devices is an effective tool in reducing emissions associated with e-textbooks.
An important corollary is the greenhouse-gas footprint of electricity, which varies by geographic region depending on the mix of carbon-based fuels versus hydroelectric, nuclear, or other less carbon-intensive sources. For example, because some regions rely heavily on coal, a single kilowatt-hour of electricity produced in the Midwest or Rocky Mountain states results in two to three times more greenhouse-gas emissions than the same amount produced in California, upstate New York, or the Pacific Northwest, which rely more on cleaner sources like hydroelectric power. (To look up your region, go to www.epa.gov/egrid.)
Electronic-textbook users who live in areas where electricity is more carbon-intensive, then, should be encouraged to use laptops or other devices that use less electricity. And all users should make an effort to limit printing.
The average e-textbook user generates 1.8 pounds of CO2e over a single course simply by printing pages from the text. These emissions are from the production of paper used in printing (we exclude the electricity consumption of the printer which is too small to be material). However. emissions vary widely depending on how (and how much) students print. The printing-related emissions of a student who prints on virgin paper, single sided, with one textbook page per printed sheet, are five times those of a student who uses recycled paper, prints on both sides, and prints two textbook pages per side.
Faculty members and administrators should consider educating students on how to print more efficiently, either through classroom instructions or more comprehensive campus-awareness campaigns. Administrators should also purchase campus printers that are capable of double-sided printing, and should consider making that the default setting on campus printers.
A related and unexpected insight is that a small minority of students print out a majority of pages. Educating these students should be part of a good greenhouse-gas management campaign. Our data show that an average e-textbook user printed approximately 12 percent of the 500 pages of assigned reading. However, that average is misleading. Some 78 percent of those surveyed printed no pages, while the remaining 22 percent printed an average of 276 pages. The carbon footprint of e-textbook users who printed out the assigned reading pages was approximately 75 percent of that of a brand-new hard-copy textbook that is never reused. From an emissions perspective, it would have been better for these students to buy a new or used hard copy and resell it at the end of the semester.
Faculty members and administrators should make sure students understand that opting for an e-textbook and then printing a huge number of pages from it is environmentally unfriendly. Faculty members should also recognize that forcing students who prefer the printed page to buy e-textbooks is unwise.
The answer to the question of which is best, then, is that it depends. More precisely, it depends on the behavior of our students—and that is something that faculty members and administrators can strongly influence.