Banana Index

The Economist’s Banana index - first unveiled in the article "A different way to measure the climate impact of food". Updated yearly.

Methodology

The banana index gives the greenhouse-gas emissions of foods - by weight, calorie, or protein - by their equivalent in bananas. Greenhouse-gas emissions are in CO2-equivalents, with non-CO2 gases converted according to the amount of warming they cause over a 100-year timescale.

Mathematically, this means that for a given metric, the banana score is the ratio of emissions efficiency. For instance, strawberries bring about 5.18 kilograms of CO2-equivalents per 1000 kilocalories. Bananas bring about 0.88 kilograms of CO2-equivalents per 1000 kilocalories. Strawberries banana score, by calorie, is therefore equal to 5.18/0.88, which rounds to 6.

Sources

Our World in Data (2023). Data Explorer: Environmental Impacts of Food
M. Clark et al. (2022). Estimating the environmental impacts of 57,000 food products.
Poore, J., & Nemecek, T. (2018). Reducing food’s environmental impacts through producers and consumers. Science, 360(6392), 987-992.

Suggested citation

The Economist and Solstad, S. (corresponding author), 2023. The Economist's Banana index. First published in the article "A different way to measure the climate impact of food", The Economist, April 11, 2023.