According to scientists at the American Union of Concerned Scientists what we put on the table accounts for one fifth of the environmental impact of an average family. This means that when we do our shopping we can choose to exploit the environment or, conversely, to respect it. But what are the parameters to take into account in order to become sustainable consumers?

1 Organic: it saves and absorbs CO2

As well as consuming less energy and emitting fewer greenhouse gases, organic farming acts as a carbon sink: every hectare cultivated in this way absorbs one and a half tonnes of CO2. The Fao, in its report "Agricoltura biologica e sicurezza alimentare", writes that "the strengths of organic farming are its independence from fossil fuels and its reliance on locally available means of production. By working with natural processes, organic farming increases the resilience of ecosystems in the face of difficult climatic conditions." Organic livestock farming is also less impactful because, thanks to the type of diet given to animals and reduced overcrowding, it generates lower emissions.

2 In season costs less. For the environment too

For the conscious consumer, expecting to eat everything all year round is anachronistic, as well as costly and lacking in flavour. Vegetables grown out of season grow in heated greenhouses, where recreating ideal growing conditions artificially requires a great deal of energy and a great deal of chemistry, with unsustainable environmental costs. And there's more. Often, even the most energy-hungry greenhouses are not enough to supply us with what we want, and so we are forced to import food from other countries. Products grown in the "right" season are tastier, richer in nutrients and beneficial active compounds, and less impactful on the environment. They grow under natural atmospheric conditions, without forcing or wasting energy; as well as undergoing fewer treatments with chemical substances, they require less work with mechanical equipment and lower energy expenditure.

3 The neighbour's fruit is always greener

Food that comes from far away requires complex supply chains and long-distance transport, which makes it unsustainable. The so-called "short supply chain" is one that connects farmer and consumer directly, reducing transport, packaging and costs, all to the benefit of the environment. Products grown in one's own geographical area, especially if organic, are therefore the preferred emission-free shopping choices for keeping carbon dioxide in the atmosphere — responsible for the greenhouse effect — in check. It is also important to consider that very often food that comes from far away is only apparently fresh: in reality it is harvested unripe, stored in special modified-atmosphere refrigerators, treated with pesticide gases, and has lost most of its vitamin content and flavour.

4 Less meat helps the environment

According to research by Stockholm University, a meal with meat and other imported ingredients generates nine times the CO2 of a vegetarian meal prepared with local foods. This is because every kilogram of meat "eats up" as many as ten kilograms of grain and fodder, consuming ten times more land than is needed for the caloric equivalent of a plant-based diet. The production of one kilogram of meat involves, on average, the emission into the atmosphere of 30.4 kilograms of equivalent carbon dioxide, whereas for the same quantity of pulses the average emission is 26 times lower. And water consumption for one kilogram of meat is 15,500 litres, compared with an average of 100 litres for one kilogram of vegetables. Finally, the waste produced by cattle emits a considerable quantity of methane and nitrous oxide, harmful greenhouse gases.

5 Packaging: no, thank you

Where possible, it is always better to buy food that is not packaged. Wrappings and packaging have an environmental impact that should not be underestimated, and according to recent studies they contain chemical substances that are potentially harmful and can easily migrate into food. If packaging is truly indispensable, we should take care to choose it in recycled material, in bio-plastic or in paper certified from sustainably managed forests, designed to save space and raw materials.

6 Fresh beats preserved and processed

It is better to always read labels carefully and buy foods that are less processed and contain fewer additives. The more a food has been treated, flavoured, coloured or irradiated, the more it is depleted of nutrients and laden with potentially harmful additives. In addition, the energy consumption required to produce fresh foods is lower.

7 Use your car intelligently

Let's be honest: we go shopping by car most of the time, especially if we live far from the shops. To pollute less and save time, let's try to plan our shopping trip by combining it with some other errand for which the car is needed. Let's prepare a shopping list so we don't risk having to go back to buy something we forgot. And if we have friendly neighbours, or friends whose schedules align with ours, let's do carpooling with them to our trusted retailer.