From a nutritional point of view, a balanced diet, like the Atlantic or the Mediterranean, presents multiple benefits for our health, as it helps mitigate and reduce the negative impact of various diseases.
Personal benefit can also be extended to the collective good and contribute to caring for the planet when we consume products that respect the environment, since it must be taken into account that the production and consumption of food carries a great environmental impact.
To elucidate the quantification of said impact, there are two indicators that we can use: carbon footprint and water footprint.
Carbon footprint and water footprint
The carbon footprint is a measure of greenhouse gas (GHG) emissions and is defined as the amount of carbon dioxide equivalent that a product generates in a period of time throughout its life cycle (extraction, production , packaging, transport, consumption and waste management).
Together with the energy and transport sectors, the food sector is one of the anthropogenic activities with the highest GHG generation.
Currently, the Paris Agreement tries to put a limit on all these emissions, so that each country commits to an effective reduction of them.
CO₂ emissions per capita in the world. The three main emission sectors: energy, transport and food. (Photo: Gumersindo Feijoo / CO2.Earth)
On the other hand, the water footprint quantifies the total volume of fresh water used throughout the entire value chain to produce the goods that we habitually consume.
The Food and Agriculture Organization of the United Nations (FAO) has established that a 70% of the world’s water footprint is related to food production.
The values of both footprints are quite variable depending on the production system and the type of food:
Fruits have mean values of 350 g CO₂ (eq) / kg and 900 L / kg for the carbon and water footprint, respectively. Legumes and vegetables present average values of 450 g CO₂ (eq) / kg and 250 L / kg. In milk and milk derivatives, values are observed in a higher order of magnitude, standing at averages of 1,500 g CO₂ (eq) / kg and 1,000 L / kg. Fish and meat show notable variations depending on the species. As an example, sardines are at 360 g CO₂ (eq) / kg, cod at 1,500 g CO₂ (eq) / kg, chicken at 3,000 g CO₂ (eq) / kg and veal at 9,000 g CO₂ ( eq) / kg.
Carbon footprint and water footprint of some of the foods that are part of the typical Spanish shopping cart. (Photo: Gumersindo Feijoo)
How to choose the most sustainable foods
Once the diet appropriate to our lifestyle, age and health status has been defined, we have a wide variety of foods with similar functionalities and nutritional properties.
Milk and derived dairy products use a considerable amount of fresh water for their manufacture. (Photo: Getty Images)
Then comes the time to introduce 5 basic rules that are easy to incorporate into our daily consumption that, in general terms, allow us to guarantee a minimization of the environmental impact of the food to be consumed.
1. Verify the origin of food
As more than 15 years ago a large French food distribution chain was advertising: Moins de transport, moins de CO₂ (Less transport, less CO₂).
Under this premise, the name of awareness of Km 0 has arisen, which consists of identify food produced within a 100 km radius to the point of consumption, thus being a call to promote the local product.
2. Analyze the container
Often the continent has a greater impact than the content.
Containers can have a high intensity of material (overpacked) and energy (consumption of fossil fuels in their manufacture).
Guide the purchase to products with minimal and biodegradable packaging it is always a good environmental option.
3. Respect the temporality of the products
It is associated with each season of the year and region of the planet, according to the natural cycles of production.
Coordination between climatic conditions and production systems entails a notable reduction in the carbon and water footprint.
4. Look for the presence of eco-labels
They can certify and guarantee that various ecological criteria are met, which in turn allows to enhance and encourage the incorporation of these strategies in marketing.
Although it is true that the application of these four rules will depend on the supply, it is ultimately about influencing it with our demand.
5. Reduce food waste
This fifth and final rule it depends exclusively on the consumer.
It is enough to think about the amount of matter and energy necessary for food to reach our refrigerators and cupboards, so that unfortunately it is not consumed and, therefore, it becomes directly waste.
Greater awareness in this regard would help reduce the current average waste in our homes.
Greater awareness of what it means to produce food can lead to greater use of it. (Photo: Getty Images)
A 50% reduction in the loss of food in households can lead to an annual emission of half a million tons of CO₂ (eq) in countries like Spain.
Taking into account that the average value in the CO₂ market during 2020 was € 24.75 / ton, it would represent bonds worth 12 million euros) and 510 Hm³ of water. Practically the annual water consumption of cities like Berlin and Madrid).
A simple spreadsheet is available at this link to estimate the environmental and economic impact produced by the waste of 64 most common foods in the consumer’s shopping cart.
It is time to become an active part of the planet’s environmental commitment, each of us can contribute our grain of sand.
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* This note was originally published on The Conversation. Click on this link to access the original article.
Gumersindo Feijoo Costa is Professor of Chemical Engineering at the University of Santiago de Compostela, Galicia, Spain.
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