Mapped the footprint of food production on climate

When the food we eat arrives on our table, it has traveled a long journey: from production, processing and distribution to all of us consumers. “The food system is the biggest threat to biological diversity and one of the worst drivers of the climate crisis,” says Daniel Moran, a researcher in the Department of Energy and Process Engineering at the Norwegian University of Science and Technology (NTNU).

Moran co-authored a large study that produced digital maps showing the pressure the global food system is exerting on the environment and climate. “No one had ever done this before and the mapping was a gigantic task,” explains the researcher. Moran collaborated with 16 researchers, including those at the University of Leeds and the University of California, Santa Barbara.

“There are many foods on the planet and numerous ways to produce them. The consequences are equally numerous and difficult to calculate. By better understanding negative impacts, we can achieve more environmentally efficient food production . In this way we will protect the environment and help ensure enough food for the world’s population,” says Moran.

When the researcher uses the word efficiency, he refers to the lowest possible environmental impact per kilogram of food produced. Moran’s contribution to the study was to map the environmental impact that international trade causes.

The five worst offenders

The study shows that five countries – China, India, the United States, Brazil and Pakistan – are responsible for almost half of the global environmental impact of food production. The researchers did not “crown” the countries with the lowest environmental footprint for one simple reason: they are poor countries that live with food shortages and hunger. The researchers obtained data on 99% of all water and land-based food production recorded in 2017. What is unique about this study is that the research team considered the main types of pressures that food production exerts on the environment: CO2 emissions, water use, habitat destruction and pollution .

They also followed the entire “ life cycle ” of food – from the sowing of the grain and the birth of the farmed animal to the bread and slice of meat on the consumer’s table – to determine the total environmental impact. Soil depletion, pesticides, toxin runoff, animal feed, irrigation, diesel fuel for transportation, and emissions from fertilizer production—all are factored into their grand calculus. Mapping the “travel kilometers” of foods was not easy.

For example, a frozen pizza may contain ingredients from different countries. Denmark, which exports pork in large quantities, imports pig feed at the same time. Even the journey of the cattle, passing through the dairy where the milk is processed, up to the breakfast table is anything but direct. In some countries, a simple product such as yoghurt may include both dried milk and imported dried fruit. The study considers the sea, water and land as a whole. Pigs and poultry have a footprint on the marine environment because they eat herring, anchovies and sardines. And on salmon farms, the latter consume land-grown vegetable feed.

Geographic overview

Using all the data collected, the researchers created a large number of specialized maps that can be combined to study the different effects. The maps provide a simple picture that allows you to directly compare almost any food from different regions.

The study shows that the production of dairy products and beef occupies 25% of the agricultural area. Livestock farming has often been portrayed as having the most damaging environmental impact , because it occupies the majority of grazing land, uses a lot of water, and produces large methane emissions. However, the survey shows that pig farming carries a higher environmental burden, mainly due to the large amount of resources used for feed production.

“In general, locally produced foods are the most environmentally friendly option, but we were surprised by how much the production footprint of the same product varies in different countries,” says Moran. “A food product can be sustainable if it is produced in one country, but not in another. For example, soybean production in the United States has been found to be twice as environmentally efficient as that of India.”

The good news is that during the COP27 climate meeting in Egypt, Daniel Moran learned that the research project he participated in has already been put to good use. The Nature Conservancy will use the study to advise the world’s food giants on how to find the most environmentally efficient solutions.

• The environmental footprint of global food production (nature.com)