Which Is The Most Carbon Intensive Food?
I was in Harrods this weekend and I was transfixed by a punnet of air freighted strawberries from Japan at a cost of £180. . . I thought that was horrific. Then in my linkedIn feed on the Monday morning, I saw Cathay Cargo advertising their ability to air freight wagyu beef, or king crab from one side of the planet to the other. But which is worst?
Air Freighted Wagyu Beef from Japan to USA 84kg/co2e/kg meat
Why is Air Freighting So Bad for Global Warming?
Essentially, air freighting food has a big carbon footprint because airplanes burn a lot of fuel. This releases a lot of greenhouse gases into the air, much more than ships or trucks do. Because many air-freighted foods are things that spoil quickly, they need to be moved fast, which means planes are used even though they’re bad for the environment. Also, emissions from airplanes at high altitudes are more harmful than those at ground level.
How Much Carbon Dioxide is Emitted?
Based on a 0.3 x 0.3 x 03 box weighing 4kg, the airfreighting of this crab would be 24kgCO2e.
The actual meat itself has a carbon footprint of 3kg between and 8kg CO2e per kg. The 3kg example here is not valid, because they have included the whole animal weight, and of course the shell so the footprint is about 5 times higher. So actual the footprint is somewhere between 8kg and 15kg.
Sneaky Reporting
Lukes Lobster report that there lobster (analogos of crab) is one of the lowest carbon protein sources. Look at the below graph from Lukes Lobster (used under fair use).
“3.13 LB FOR EVERY POUND OF LIVE LOBSTER WE SOURCE”
That include the shell, which discarded and weighs 80% of the animal. So the footprint is 5 times higher.
Luke’s Lobster have also cherry picked their protein sources so these lobster come out as lowest. There are several sources of vegetable protein that come out lower:
Calories vs Carbon
Crab Meat is around 143 calories per 100g. A 4kg crab will contain around 0.8kg of meat, so about 1200 calories.
The total footprint for air freighted crab, from Alaska to Japan (as advertised by Cathay Cargo) would be 40kg.
So looking at the below graph, airfreight crab is on par with ground transported beef in terms of it carbon intensity per calorie. However, this pales in comparison to Wagyu Beef, with a carbon footprint of 78kgCo2e/kg.
So Crab meat has a carbon intensity similar to lamb, and the air freighting is dominating factor in its overall footprint.
Beef is Still the Worst
Whilst air freighted crab has an incredibly carbon intensive, on a per calorie basis. Beef is still king. A 1kg Beef Steak Air Freighted from Japan to the USA would have footprint of about 55kg, niche varieties such as Wagyu can have a footprint of 78kgCo2e/kg so adding in a further 6kg for airfreight, we arrive at a whopping footprint of 84 kgCO2e/kg.
Wagyu beef is famously calorific so how does it compare with crab on a per calorie basis? 218-264 calories per 100 grams for Wagyu beef. So one kg is approx 2500. Roughly double that of crab. But it also has double the footprint.
So given the inaccuracy of the method used here, we can estimate that on a per calorie basis air freighted beef and air freighted crab have similar, very high carbon footprints.
One error might be portion sizes. Does one really eat a whole king crab, or a whole kilo of Wagyu? Probably not. But at over 10x the footprint of cheese, and 20x of eggs, air freighted beef and crab are food we should learn to live without.