How many CO2 emissions does a food emit during its life cycle?
There are few human activities whose balance in terms of greenhouse gas emissions is zero or negative. Food production is no exception. The emission of greenhouse gases is not the only impact of producing food, but it is the one that we are going to focus on in the following lines.
From beginning to end
To understand the impact of a product, in this case a food, we must know the entire process carried out so that we can eat it at a certain time and place. Each food is different in terms of the stages of that process, and each part of the process also changes between some foods and others.
The following stages are the usual ones in most of the things we consume, especially if we live in a city:
1-Cultivation of the land or animal husbandry.
This first step includes activities such as land use change with all the impacts it entails, both on the surface and below it. Also the emissions associated with those of the growth process of the plant or animal itself, such as the methane emitted by a cow during its life, or by rice while growing. And we use fertilizers, machinery and energy to be more productive, something that we cannot ignore in terms of greenhouse gas emissions. In addition, in the case of animals they require to be fed, and that food must also be cultivated.
Usually food requires some kind of treatment. Less if they are fresh, but more if they are treated, chopped, prepared for preservation, or cooked (among other possibilities). This will be done in a factory, slaughterhouse, etc., and will require energy to produce heat, cold, move machinery, etc.
Many times what we eat has not been grown and processed near us, and to a greater or lesser extent it requires transporting it to us. Sometimes this transport is short distance and using a low-emission medium, in others it is quite the opposite. The impact of transporting vegetables from Tordesillas to Valladolid in a van is not the same as cherries from Chile to Spain by plane; in the latter case, transport can have a considerable impact on the total emissions of a food.
We already have the food in the wholesale market, or even in the neighborhood store. We will usually need to have it refrigerated somehow, in addition to having the lights on all day if it is a store. All this so that the client finds it in the best conditions, both aesthetic and hygienic.
To all this we must add that normally each food has some kind of packaging. Sometimes from the factory, where they have arranged it on a plastic tray, or inside a cardboard box. And other times the seller himself wraps it or uses a bag, to which he may then add another if we do not bring one from home.
All these stages constitute the life cycle of a food, and all of them are responsible for emissions.
Each type of food is different, and the distribution of emissions between stages also changes. For example, beef has the greatest impact on animal husbandry, both in land use change and in the emissions of these animals themselves. But if we go to pork, we see that the most important impact is associated with the feeding of these.
And one more…
What happens to the remains of what we don’t eat? The waste needs to be picked up by the garbage truck, sorted, and treated in some way in a landfill, when not simply deposit them and wait for them to decompose. All this has associated greenhouse gas emissions, by the fuels used, or by the methane emitted into the atmosphere during decomposition.