Emissions from food production are vastly underestimated, a new study claims

A new global analysis concludes that about a third of our emissions can be traced to food production. The report, developed jointly by the UN Food and Agriculture Organization, NASA, New York University, and experts at Columbia University, finds that food is a significant contributor to climate change due to the amount of greenhouse gas emissions emissions generated within the farm and on agricultural land. Around a third (and potentially even more) of our emissions come from agriculture.

Image credits: Dan Meyers.

The more researchers look into food production, the more they realize that it’s actually a more integral part of our greenhouse gas emissions than we thought. It’s not uncommon for agriculture to be discarded as an afterthought in the climate debate, but in the past few years, studies have shown agriculture to be a far bigger player than we tend to give it credit for.

Global emissions from agriculture and associated land-use account for about one-fifth of all emissions — already a hefty amount. But that’s just food production — when we also consider all the other aspects involving agriculture (manufacturing, processing, storage, transport, waste disposal, and environmental impacts), the figure can get closer to 40%. In developing countries, they can amount to half of all emissions.

Based on this new analysis, previous reports (such as the one from the Intergovernmental Panel on Climate Change or IPCC) missed many important food-related emissions.

“Our new comparative mapping of food system categories and activities and improved data have shown that significant emissions are also contributed by non-IPCC agricultural and land sectors, such as on-farm energy use, domestic food transport and food waste disposal. Taken together, the global food system represents a larger GHG mitigation opportunity than previously estimated,” the researchers write in the study.

The lead author of the analysis, Francesco Tubiello, heads the environment statistics unit at the Food and Agriculture Organization of the United Nations (FAO). Tubiello explains that when countries report their emissions from food systems, they often underestimate their contribution to climate change. The study provides detailed, country-level datasets, considering all emissions associated with agriculture; the datasets will be discussed at the UN’s Food Systems Summit, to be held in July.

In a companion piece, researchers also discussed the importance of analyzing food emissions in more detail. This paper’s first author is Cynthia Rosenzweig, an American agronomist and climatologist at NASA Goddard Institute for Space Studies.

“Beyond calculating the emissions from fertilizer decomposition in the soil, from converting forests to pastures , from diesel combustion in tractors and fishing boats , and from cows and other ruminants , we need to cast a broader yet tighter net to better identify the myriad ways in which the food system generates emissions. For example, much of the work to address the impact of the food system on climate change globally has focused on crops and livestock, with less attention paid to aquaculture and fisheries and associated value chains,” the paper reads.

“The food system and the climate system are deeply intertwined,” said coauthor David Sandalow, a fellow at Columbia’s Center on Global Energy Policy. “Better data can help lead to better policies for cutting emissions and protecting the food system from a changing climate.”

An opportunity to cut emissions

The study also comes with some good news. Although total food emissions rose from 1990 to 2018, per capita emissions actually decreased, from the equivalent of 2.9 metric tons to 2.2 metric tons per person. This decrease is largely owed to changing technologies. But in developed countries, the per capita food emissions (3.6 metric tons per person) are almost twice as much as those from developing countries.

The study is also encouraging because it suggests that by changing our food consumption patterns, we could reduce a hefty amount of our emissions.

For instance, meat consumption is one of the main culprits on our plate, with researchers increasingly calling for a climate tax on meat in developed countries.

“Reduction in meat consumption, especially beef, can deliver health benefits, reduce greenhouse gas emissions from livestock production, and augment the potential to sequester carbon on land not used for grazing or for growing livestock feed,” the researchers argue.

It’s also important to note that as agriculture produces emissions that exacerbate climate change, this can create a feedback loop, with climate change putting more pressure on agriculture systems. It’s typically the world’s poorest that are most vulnerable to this, the researchers emphasize.

Ultimately, it will take an integrated approach to address our food production systems, focusing on activities both before and after farm production, and taking into consideration all the aspects around food production, from deforestation and land use to transport and refrigeration.

“Agriculture in developed countries emits large quantities of greenhouse gases, but their share can be obscured by large emissions from other sectors like electricity, transportation and buildings,” said Matthew Hayek, an assistant professor in environmental studies at New York University and coauthor of both pieces. “Looking at the entire food system can not only illuminate opportunities to reduce emissions from agriculture, but also improve efficiency across the whole supply chain with technologies such as refrigeration and storage.”

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