Whenever I go backpacking, I choose a flask of liquor over beer, even though I prefer beer. Why? Because the flask is lighter than a few bottles of beer. But in the ecological backpack, beer is among the lighter items you can bring! An ecological backpack, or rucksack if you prefer, measures a product’s impact by expressing its natural resource consumption in ratio of how many kilograms of natural resources are used to make one kilogram of the product. This concept helps to communicate the complex world of ecological impacts of our food decisions. Many products’ backpacks are heavier than the product itself, like beef; it needs 40 kg of natural resources per kilogram of beef. Cheese, butter, margarine, pork are the next four most “heavy” products. But beer? Delicious, wonderful beer? It is on the lower end of the scale, requiring around two kilograms of resources per one kilogram of beer. This is still high – we need to improve resource efficiency so that products get as close to a 1:1 resource use to product ratio as possible. In beer, people are highly motivated to do so – in fact, there is a new enzyme which allows direct barley to brew, which skips the malt step, lowering the ecological footprint. So for now, cheers to beers!
You may be familiar with the concept of footprinting instead – our ecological footprint, carbon footprint, water footprint, etc. An ecological footprint is defined by the Global Footprint Network as “how much land and water area a human population requires to produce the resource it consumes and to absorb its carbon dioxide emissions, using prevailing technology.” Under the water footprinting concept, beer has a global average water footprint of 75 liters of water for one glass of beer. This certainly seems like a higher impact than the backpack concept would lead one to believe. And this is the current debate; which assessment method is the best? Certain assessments are better in various situations; all have drawbacks. Those who favor footprinting point out that ecological footprint calculations include land-use indicators, while the ecological backpack does not.
As Lettenmeier explained in his presentation, “Application of the ecological backpack for the communication on sustainable nutrition“, the ecological backpack is a more easily understood method for educating the public about natural resources use in the area of food and nutrition. The resource-to-product ratio can be easily understood. Food products can be labeled with their ecological backpacks, either in text or diagrams. These backpacks could be shown in public spaces, in cookbooks, and more, to help influence more sustainable eating decisions.
Are you familiar with either concept? Which one do you find more helpful in conversations about sustainability?