How Bad Are Bananas? Summary

“How much does your cheeseburger, email, or cup of coffee truly cost the planet? The carbon footprint of everyday decisions may shock you.”

1. What is a carbon footprint, and why does it matter?

A carbon footprint measures the greenhouse gases—like carbon dioxide, methane, and nitrous oxide—linked to human activities. Each of these gases differs in its global warming power. For instance, methane traps 25 times more heat than carbon dioxide, while nitrous oxide traps 300 times more. When we calculate carbon footprints, we express them as carbon dioxide equivalent (CO₂e) for better comparison.

Carbon footprints reveal the unseen environmental price of goods and services. Developed countries often have far larger footprints. While a person in Malawi may be responsible for just 0.1 metric tons of CO₂e a year, North Americans average 28 tons. Alarmingly, in 2007, humanity collectively emitted 49 billion metric tons globally.

The author promotes a "10-tonne lifestyle," encouraging people to reduce their annual CO₂e from excessive levels to a more manageable 10 metric tons. This approach doesn’t necessitate dramatic sacrifices but relies on practical changes.

Examples

• Methane is 25 times worse for warming than CO₂, but human-led reductions could drastically limit emissions.
• In the UK, an average person emits 15 metric tons annually but is encouraged to target a 10-tonne lifestyle.
• The planet emitted some 49 billion metric tons of CO₂e in 2007, with human activity as the dominant contributor.

2. Even digital activities leave a footprint.

Digital tools like texting and emailing are part of our daily routines, but each contributes to CO₂e emissions. Texting is among the least impactful options, with one message contributing just 0.014 grams of CO₂e. Emails are slightly heftier at 4 grams each.

However, when computing becomes a global norm, these seemingly small actions accumulate. Manufacturing devices like a single iMac takes 720 kilograms of CO₂e. Beyond personal electronics, data centers storing internet content consumed enough energy in 2010 to emit 130 million metric tons of CO₂e. Their energy demands were projected to double by 2020.

This shows how even activities designed to reduce emissions can have unintended rebound effects. Emailing might replace meeting in person, but excess online communication nullifies some of its benefits.

Examples

• A single iMac’s production adds 720 kilograms of CO₂e in emissions.
• Texting generates 32,000 metric tons yearly with 2.5 trillion texts sent as of 2010.
• Data centers emitted 130 million tons of CO₂e in 2010, set to double by 2020.

3. Plastic may be bad, but paper isn't entirely better.

Plastic is infamous for its environmental harm, yet paper has its downsides too. Surprisingly, plastic bags emit fewer greenhouse gases compared to paper ones. A supermarket plastic bag contributes 10 grams of CO₂e, while a recycled paper bag typically accounts for 12 grams. The gap grows with thicker paper bags.

Paper’s ability to decompose adds another downside. As it rots in landfills, paper produces methane. The best solution is switching to reusable items like tote bags. Additionally, avoiding disposable goods, including junk mail and catalogues, would significantly help cut emissions.

Recycling paper helps considerably reduce its footprint. Recycling old paper uses half as much energy as manufacturing it from new resources.

Examples

• One regular supermarket plastic bag generates 10 grams CO₂e; a paper bag emits 12 grams.
• Junk mail contributes up to 1,600 grams CO₂e, depending on delivery and disposal methods.
• Paperback books add 1 kilogram CO₂e per book but can replace more carbon-intensive leisure activities.

4. Flying is the worst form of travel for greenhouse gases.

While traveling, different modes have different impacts. Surprisingly, fuel-efficient cars or even long train rides may beat short flights. For instance, a car emits 710 grams per mile, while a short flight from London to Scotland adds 500 kilograms per passenger—ten times more than cycling the same distance.

Why does flying rank so high? Jet fuel emissions exert more harm when released at altitudes where atmospheric conditions amplify their warming effects. International air travel often becomes the largest personal contributor to CO₂e for frequent fliers.

Reducing air travel even slightly can have an enormous positive impact compared to other smaller lifestyle adjustments.

Examples

• London-to-Hong Kong flights: A single round trip generates 4.6 metric tons of CO₂e.
• Cars burn 3.15 kilograms of CO₂e per liter of gas across average commutes.
• One cycling mile, fueled by cereal, could emit 90 grams of CO₂e.

5. Local foods are greener than imported ones.

Food choices amplify or shrink your footprint depending on how far they've traveled. For example, a locally grown apple averages 10 grams CO₂e, while apples shipped to another country can hit 80 grams. Certain fruits, like bananas, fare relatively well—even when imported—since they grow without artificial light or additional packaging.

Meat also poses challenges since ruminant animals, like cows, release methane. Nonruminant meats, such as pork, have a smaller carbon burden. By comparing options based on emission data, it’s clear local and seasonal produce dominates in sustainability.

Examples

• Bananas and local apples each measure around 80 grams of CO₂e per fruit.
• Airfreighted asparagus from Peru leaves a footprint of 3.5 kilograms.
• Sheep and cow meat doubles pork’s footprint due to methane production.

6. Beverages carry their share of emissions.

Even what you drink has environmental costs. Bottled water has over 1,000 times the footprint of tap water, largely from production and transport. Similarly, coffee and wine add significantly to personal carbon footprints due to factors like dairy and packaging.

Switching to tea or black coffee without milk dramatically reduces carbon costs. Opting for locally brewed beers or boxed wine lowers emissions, as transport and heavy glass bottling contribute to higher footprints.

Examples

• Bottled water emits 160 grams per liter, tap water only 0.14 grams.
• Coffee shop lattes can add 340 grams CO₂e per serving.
• Imported beer may leave a 900-gram footprint, while local options fall to 300 grams.

7. Domestic chores have hidden costs for emissions.

Every household appliance uses electricity, contributing to emissions. For instance, drying laundry by hand emits substantially less CO₂e compared to electric tumble dryers. Similarly, dishwashers are more efficient than handwashing only when used with precision.

Showers generally beat baths for carbon efficiency. Installing aerated showerheads, which conserve water, can cut a family’s footprint over time.

Examples

• A 60°C laundry wash with tumble drying emits 3.3 kilograms CO₂e.
• Hanging laundry saves half a metric ton of emissions annually.
• Aerated showerheads cut footprints from 0.5 kilograms to just 90 grams per session.

8. Some natural emissions are far smaller than man-made ones.

Natural events like volcano eruptions or bushfires do contribute emissions but on a scale dwarfed by human contributions. For instance, global volcanoes annually emit about 300 million metric tons of CO₂e, while humans are responsible for 49 billion tons.

Deforestation further escalates emissions by releasing stored carbon dioxide from trees—a single hectare emits as much as 500 metric tons. Concerted efforts to preserve forests would drastically cut global emissions.

Examples

• All volcanoes combined contribute less than 1% of human global emissions yearly.
• Deforestation releases 9 billion metric tons of CO₂e annually.
• Bushfires in Australia in 2009 emitted 165 million metric tons—still less than human impacts.

9. Dietary adjustments bring meaningful changes.

Food creates a fifth of an individual’s overall carbon footprint. Reducing waste and shifting consumption choices—like eating less meat and opting for local goods—can slash emissions considerably. Eliminating food waste alone provides a 25% reduction.

Cooking efficiently also lessens impacts. Covering pots while boiling and reevaluating oven usage are simple ways to make meaningful changes inside your home.

Examples

• Cutting back on beef and dairy could reduce diet-related emissions by 25%.
• Using a microwave beats stovetops for energy efficiency in some recipes.
• Choosing misfit vegetables helps markets minimize food waste and earn profits simultaneously.

Takeaways

1. Reduce air travel whenever possible, as it makes an outsize contribution to your footprint.
2. Eliminate food waste by buying only what you will eat and storing perishables properly.
3. Use reusable bags, tap water, and energy-efficient household practices to immediately see reductions.