Researchers have mapped the world’s food production footprint on climate and environment

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Livestock farming is often said to have the most negative impact on the environment, but it is not the worst. Is locally produced food always best for the environment?

The food we eat has come a long way from production, processing and distribution to all consumers before it reaches our table.

“The food system is one of the biggest threats to biodiversity and one of the worst contributors to the climate crisis,” says Daniel Moran, a researcher in NTNU’s Department of Energy and Process Engineering.

Moran was the lead author of a large study that produced a digital map of the environmental and climate pressures of the global food system.

“Nobody had done this before, and mapping was a huge undertaking,” say the researchers. Moran has worked with 16 of his researchers, including the University of Leeds and the University of California, Santa Barbara.

Improving eco-efficiency

“There are many different foods on the planet and many ways to produce them. Their environmental impacts are manifold and difficult to calculate. We can achieve production, and by doing this we help protect the environment and ensure that the world’s population has enough to eat,” 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 this research was to map the environmental impacts caused by international trade.

five major criminals

According to the study, five countries – China, India, the United States, Brazil and Pakistan – account for nearly half of the global environmental impact of food production. There’s a simple reason why researchers haven’t “crowned” the country with the least environmental impact. These countries are poor countries suffering from food shortages and hunger.

Researchers have obtained data on 99% of all reported water and land food production in 2017.

A unique feature of this study is that the research group considered the main types of pressure that food production exerts on the environment.₂ Emissions, water consumption, habitat destruction and pollution.

They also traced the entire “lifecycle” of food, from sowing grain to the birth of piglets, to bread and bacon on the consumer’s table, to determine their overall impact on the environment.

Soil depletion, pesticides, toxin run-off, animal feed, irrigation, diesel for transport, emissions from fertilizer production, etc. are all included in the big environmental accounting.

lots of food miles

Mapping the “kilos traveled” of food is not easy.

Frozen pizza can contain ingredients from multiple countries. For example, Denmark, which exports a large amount of pork, also imports pig feed.

There is also not always a direct route for dairy products from the cow to the breakfast table. In some countries, a simple product like yogurt may contain both imported milk powder and dried fruit.

This study considers the sea, water and land as a whole. Pigs and poultry leave their mark on the marine environment as they eat herring, anchovy and sardines. Also, in salmon farming, salmon feed on vegetables grown on land.

Geographic overview

Using all the data collected, researchers created a number of specialized maps that could be combined to study different effects. The map provides a simple picture that allows direct comparison of nearly all foods from different regions.

The study shows that 90% of all food production occurs on 10% of the world’s land area.

Dairy and beef production accounts for 25% of agricultural land. Animal husbandry has often been portrayed as having the most detrimental impact on the environment, as it occupies the most pasture land, uses the most water, and emits the most methane.

However, research shows that farming with pigs poses a greater environmental burden, mainly due to the large amount of resource used in the production of fodder.

surprisingly variable

“Locally produced food is generally the greenest option, but we were surprised that the production footprint of the same product varies so much from country to country,” says Moran. Soybean production in the United States, for example, was found to be twice as eco-efficient as in India.”

no super diet

Researchers don’t single out a particular diet as the best for their environment.

The optimal diet varies greatly from country to country. Moran says that local food is often sustainable, but people may want to find a balance between the desire to be self-sufficient in all types of food and the most eco-efficient production possible. I point out that it does not.

At the COP27 climate conference in Egypt, Daniel Moran learned that a research project he had been involved in was already being used.

The Nature Conservancy will use this research to advise global food giants on how to find the most eco-efficient solutions.

reference:

Halpern et al. “Environmental Footprint of Global Food Production”, natural sustainability,roll. DOI: 10.1038/s41893-022-00965-x Summary.