EATING A JUICY steak is worse for the surroundings than frying up some tofu: that a lot ought to come as no shock. Going vegan can dramatically reduce the carbon footprint of your food regimen. However what concerning the fewer energy, and decrease ranges of protein, present in most plant-based meals when put next with meat? That makes it onerous to match emissions of meals which are equally nutritious.
To make the relative carbon impression of meals simpler to digest, The Economist proposes a banana index (see our interactive chart beneath). It compares well-liked foodstuffs on three metrics—weight, energy and protein—listed to the standard banana, a fruit of middling local weather impression and dietary worth.
Indexing greenhouse-gas emissions to a single meals offers a way of how completely different foodstuffs rank. Sadly for carnivores, beef is unhealthy for the surroundings irrespective of the way you slice it. Producing one kilogram of mince causes as many emissions as 109kg of bananas (name it a “banana rating” of 109). Modify for dietary worth, and beef’s banana rating falls to 54 (one calorie of beef mice causes 54 occasions as a lot carbon emissions as one calorie of banana). By protein, it scores seven.
Poultry scores 11 bananas by weight and 4 by calorie. Nevertheless, as a supply of protein, it’s extra carbon-friendly than bananas: poultry protein emits simply three-fifths of the identical quantity of banana protein. The identical applies to salmon. Unsurprisingly, plant-based options to meat do even higher: a meat-free burger, for example, scores simply one-fifth of the emissions of bananas per gram of protein. (Different plant-based meals, equivalent to grapes, sugar and coconut milk, comprise barely any protein which sends their banana scores hovering.)
Some meals that out-emit bananas on one metric put them to disgrace on one other. The most important variance between emissions by weight and energy is in olive oil, which has a banana rating of six when measured by kilogram, however scores 0.7 when measured by energy. Others embrace breakfast cereals, cashew nuts and croissants—which all flip from unhealthy scores to good when measuring by calorie.
Our banana index depends on common emissions for a given meals. In the true world some producers are extra climate-friendly than others, and a few meals journey farther to customers. However usually, variations between meals are a lot better than these variables inside them. For all of the emphasis on regionally produced meals, transportation contributes lower than 10% of most meals’ whole emissions; for beef it’s normally lower than 1%. Our banana index additionally doesn’t seize different environmental impacts, equivalent to land and water use (although right here too, beef tends to fare poorly).
Polling in Europe by Ipsos for Yara, a fertiliser agency, suggests that the majority customers wish to be extra climate-friendly—and with meals manufacturing liable for maybe 1 / 4 of world emissions, consuming with the local weather in thoughts would make a distinction. The survey confirmed that simply 31% of respondents discovered it straightforward to make sustainable selections. Three-quarters stated they need labels that may clarify the local weather impression of their meals. Research have discovered that labels encourage customers to decide on lower-emission choices, though they don’t seem to be in widespread use. Within the meantime, our banana index may assist.■
Learn extra of our evaluation on meals and the surroundings:
Treating beef like coal would make a big dent in greenhouse-gas emissions
If everyone were vegan, only a quarter of current farmland would be needed
How much would giving up meat help the environment?
Meet the vegans having better sex than you
