We know that food weighs heavily in the carbon footprint of humanity. But what exactly does this represent? And what solutions would reduce these emissions? Authors deliver new answers.
” Emissions from food transportation account for nearly half of direct emissions from on-road vehicles “, deplores Mengyu Li. With his team, they are at the origin of research work aimed at quantifying the carbon impact of the production and transport of food around the world. The results, published on June 20, 2022 in nature foodbring striking figures.
Of all the emissions produced by humanity, food accounts for almost a third. The mere phase of transportation weighs 3 gigatonnes of carbon dioxide emissions each year. The import principle is also in question: high-income countries represent 12.5% of the world’s population, but 46% of food-related emissions.
“Our study estimates that global food systems, through transport, production and land-use change, contribute about 30% of total human-produced greenhouse gas emissions. Thus, the transport of food, which represents about 6%, constitutes a significant proportion of global emissions. »
Beyond these figures which depict an unencouraging ecological landscape, the study also provides elements for action by trying to answer the question: what would happen if we ate locally and in season?
What would local food change?
According to the researchers’ calculations, local power would reduce the transport footprint by 0.27 gigatonnes (0.24 gigatonnes in rich countries alone), and the production footprint by 0.11 gigatonnes. That is 0.38 gigatons in all.
However, there are regions where local food is difficult to implement. In these cases, the authors evoke the possibility of new mechanisms: “ there is considerable potential for peri-urban agriculture to feed city dwellers “, for example. Not to mention mitigation solutions: investing in cleaner energy sources for transport vehicles; encourage food companies to use lower-emitting production and distribution methods, such as natural refrigerants “.
The solution is us
Although the mechanisms evoked by the authors of this work are mainly at the macro level, since they must be put in place by governments and companies, an important part of their conclusion concerns the population itself. In the sense that supply evolves from demand. As with ultra-processed food, which should be avoided as much as possible, food production and transport methods also play a role in everyday choices.
“Changing consumer attitudes and behavior towards sustainable food can have huge environmental benefits writes one of the authors, David Raubenheimer. We are used to looking for the same fresh foods all year round, when most of them have seasonality, and that is a mistake. ” An example is the habit of consumers in rich countries to demand non-seasonal foods all year round, which must be transported. “It is better to opt for” local seasonal alternatives, as we have done for most of our species’ history “.
All of these adaptations are, after all, intended to provide a healthier planet to future generations, remind the authors (and it is also a question of curbing the sixth extinction).
And the meatless diet?
What about food production methods? ” Prior to our study, most of the attention in sustainable food research has focused on the high emissions associated with animal-based foods, relative to plants. “, specify the authors. And indeed, the industrial production of meat is one of the highest current sources of greenhouse gas emissions (14.5% of the total).
It has now been scientifically proven that plant-based food, without meat therefore, is 10 to 50 times less emitting and that it is therefore a key in the fight against climate change. Not to mention the problem of land use. The 5th report of the IPCC (2018) thus evoked the importance of moving towards diets where meat would have a much lower share than at present.
The authors of this new study dedicated to sustainable food believe that it would ultimately be a question of combining the approaches: “ Our study shows that in addition to moving towards a plant-based diet, eating local is ideal, especially in wealthy countries. »