This article has been written by Javier Santos, full professor at Tecnun (University of Navarra) and coordinator of MCUBO.

How soon we forget things! A couple of months ago the vicissitudes of a young activist filled the covers and positioned all of us in favor or against her feat of crossing the ocean in a catamaran to avoid the carbon footprint of her trip. I even read news stories that calculated the CO2 impact of every email we sent… Come on, that’s crazy.

What was clear to me in the news I read those days is the difference between icon and model. Although many young people see in Greta a role model, her approach to everyday situations is not extensible and, therefore, would never be a reference to imitate. Those of us who consider her an icon of the fight against climate change and the use of natural resources are more aware of the impact of our actions and try to mitigate it. But we cannot all be Greta.

Just the other day, I was in the supermarket to buy a vegetable stew and I thought for sure that it would be better for the planet to buy the products and make a stew at home instead of buying a ready-made jar, because we have all heard how much water the sector consumes, about 28,500 litres of water per tonne of vegetables and that is a lot of rubbish we cannot afford. So I thought about “going Greta” with the vegetable stew.

To prepare the vegetable stew just as it comes in the jar, you have to choose the vegetables: artichoke, peas, asparagus, green beans and carrots; then wash them carefully (although we all do it with a jet for comfort, 15 litres); blanch them in a pot (each vegetable has its time and we would do them separately, 15 litres); and clean the pot and tools (in a dishwasher shared with plates and glasses we put 20 %, 5 litres).

According to my calculations I would need about 35 liters of water for a pot for two people. If we take into account that from one ton of selected vegetables approximately 2300 jars of vegetable stew are obtained, the result could not be more evident. We would spend more than three times as much water at home as the company uses, and if we did that with the 2,300 jars we would use 80,000 litres of water!

Commenting on this situation with a friend, she corrected me by saying that it is not entirely true; that the cooking water can be made into delicious broths and taken advantage of… And she was right, although the company would still be more efficient because the governing liquid in the jars contains a good part of the nutrients and can be used in the cooking of vegetables or in the preparation of broths. In any case, we will continue to need icons like Greta to make us think about these issues and to protect our natural resources.