How Bad are Bananas?

How Bad are Bananas: The carbon footprint of everything by Mike Berners-Lee, 2020, Profile Books.

This book, “How Bad Are Bananas? The Carbon Footprint of Everything” by Mike Berners-Lee, sets out to answer the questions of a carbon-conscious shopper and many more besides, aiming to provide a sense of the carbon impact of everyday activities and thoughts. The author wants to cultivate a “carbon instinct” in readers, enabling them to make reasonable estimations of the footprint of various things they encounter.

The book covers a wide range of items, from the seemingly insignificant, such as a text message or a cup of tap water (under 10 grams of CO2e), to much larger impacts like a volcano or the World Cup (1 million tons and beyond). It delves into the carbon footprints of food, travel, household activities, and even broader concepts like data centers and war.

Berners-Lee clearly defines his use of “carbon footprint” as a metaphor for the total climate change impact, using “carbon” as shorthand for all global warming greenhouse gases. He acknowledges the impossibility of measuring the true carbon footprint with perfect accuracy due to the complexity of factors involved, such as farming, transport, storage, and related processes. However, the book adopts a pragmatic approach, aiming to provide the most realistic estimates possible while being transparent about the inherent uncertainty. The author emphasises getting the orders of magnitude clear rather than absolute precision. He encourages readers to view the numbers as “best estimates” with a likely range and welcomes feedback on potential improvements. He argues that even with uncertainty, these estimates are good enough to differentiate between high-impact and low-impact choices, making decisions more informed than having no guidelines at all. The book is presented as an “early map,” acknowledging potential inaccuracies but hoping to be better than what the reader had before, and aiming to improve the “carbon map” in the reader’s mind.

The book is not intended as a prescriptive list of actions but rather as a tool to help readers “pick their battles” and understand where they can get the best return for their effort in reducing their carbon footprint. The author hopes that by the end, readers will have identified a few things that can improve their lives while significantly cutting their carbon impact. He respects that the level of action is a personal decision.

Berners-Lee attempts to make the abstract concept of carbon more tangible by introducing the idea of a “10-ton lifestyle” as a unit of measure. He illustrates how easily this budget can be consumed by activities like car commutes, daily cheeseburgers, and flights.

The writing style appears accessible and engaging, encouraging readers to “dip in,” “keep this book by the loo,” or read it cover to cover. The author uses analogies (like comparing carbon costs to financial costs and the difficulty of footprinting to sailing with an old map) to aid understanding. He also injects personal anecdotes, such as his supermarket experience with the journalist and his office’s milk-free drink experiment. The author encourages readers to engage with the material, talk about it, and even take issue with it.

Specific examples highlighted in the excerpts include:

• Bananas: Found to be a “fine low-carbon food” when imported, and zero carbon if grown in one’s own garden.

• Tap water: A cup has a very low carbon footprint.

• Web search: Estimated to have a minimal carbon impact.

The author touches upon the importance of considering the full life cycle of products, including emissions from extraction, production, transportation, and disposal. He also notes that seemingly “green” choices, such as organic eggs, might not always be the lowest-carbon option.

Ultimately, the book encourages readers to develop a “carbon awareness” alongside other considerations in their lives and to identify areas where cutting out “junk” can improve both their quality of life and reduce their carbon footprint.