On the whole, I’m a fan of Barbara Kingsolver’s book Animal, Vegetable, Miracle, in which she documents her family’s experiment with a year-long local, seasonal diet. However, I disagree with her about bananas, which she portrays as a Fruit with a Massive Carbon Footprint, never again to be purchased or consumed by anyone who truly cares about climate change. Bananas aren’t perfect – commercial bananas available in North America are not diverse, as they are propagated asexually from just two related cultivars – but nor are they guilty, ripe or unripe, of completely failing the green, low-carbon lifestyle test. Not even close, as it turns out.
As a person who refuses to stop buying (and eating) bananas, I was intrigued by the title of a new book by Mike Berners-Lee: How Bad Are Bananas? The Carbon Footprint of Everything. Of course there are melting glacierloads of books, websites, and blogs that purport to calculate your carbon footprint, advise you on attaining a greener lifestyle, and/or smack you on the nose with a rolled-up recycled hemp newspaper, for your decadent and wasteful Global North lifestyle. But this book seemed different, so I purchased the KIndle version, and was pleasantly surprised by the fact that it is indeed different from the usual greener-than-thou reading fare.
Berners-Lee uses carbon dioxide equivalents (CO2e) to include a variety of greenhouse gases in calculating the carbon footprints of a diverse array of material goods, activities, comestibles, and events. Most of the book provides detailed accounts and comparisons of these calculations, divided into groups starting with “Under 10 g”, and ending with 100 tons to 1 million tons (+).” For example, you can send a text message, or drink a cup of tap water, for under 10 grams of carbon dioxide equivalents. Bananas and apples are worth 80 g each, while an orange is worth 90 g; these fruits are typically transported by ship, which is a fairly low-carbon alternative. Within the 10 kg to 100 kg range are things like a congested commute by car, 5 miles each way (22 kg), and a night in a typical hotel, including dinner and breakfast (24 kg). Shoes also fall within this range, with Crocs weighing in at 1.5 kg, and leather shoes at 15 kg, carbon dioxide equivalents.
The high-carbon items, above 100 kg carbon dioxide equivalents, are especially interesting, and somewhat depressing. A return flight between New York City and Niagara Falls incurs 500 kg, while taking the train for the same trip weighs in at 120 kg. Flying economy (return) between Los Angeles and Barcelona is worth 3.4 tons, while a return flight between New York City and London costs about half as much, in carbon dioxide equivalents. Basically, flying is an extremely carbon-intensive mode of transportation: the fossil fuel requirements are huge, and the altitude at which most emissions occur must be factored into the environmental damage rating. A heart bypass operation costs 1.1 ton, and a two-car accident that blocks a busy highway for several hours costs 50 tons. A community swimming pool, such as the one near my house where I exercise weekly, is worth 400 tons per year, and one space shuttle flight costs 4600 tons. The 2010 World Cup in South Africa weighed in at a massive 2.8 million tons of carbon dioxide equivalents.
One idea that Berners-Lee suggests is attempting to attain a 10-ton per year lifestyle. One return flight, even within the US, would make this goal very challenging. I have just one flight such planned this year, for a grant review session in Washington DC; for the same trip, I’ll also incur 3 nights in a hotel, with meals. I’ve consoled myself somewhat for the lack of time to travel for fun this year by joining knitting clubs, in which participants receive kits with hand-dyed yarn, patterns, beads, and accessories by mail. However, most of the yarn is wool-based, made from sheep which, like their ruminant relatives cows and goats, emit significant amounts of methane. Still, not as bad as flying around the country to attend workshops and meetings.
There are a lot of simple and relatively painless changes that can be made to reduce one’s carbon footprint, however, and those suggestions are one of the things I liked about Berners-Lee’s book. I also liked his descriptions of his calculations, and the inclusion of a section on “where the numbers come from.” I found the additional section on the carbon footprint of food especially instructive, with “low-carbon food tips”, and appreciated the analysis of the cost efficiencies of things such as attic insulation and offshore wind farms. I skipped over the section “for climate change skeptics” because, well, I accept the assumptions that climate change is a big deal, and that humans are causing it. I suspect that if you’re a climate change skeptic, you won’t like the book much – ditto if you’re locked into denial about the size of your own carbon footprint.