Large-scale changes to the global food system could not only reduce greenhouse gas emissions, but also achieve net negative emissions by 2050, according to a new study published in the open-access journal PLOS Climate.
As the Earth’s human population grows, greenhouse gas emissions from the global food system will increase.
A new study by an international team led by Maya Almaraz of Princeton University in the US and Benjamin Houlton of Cornell University shows that improved agricultural technology and management could not only reduce that growth, but eliminate it entirely by creating a net. Negative emissions, that is, by reducing more greenhouse gases than are added by food systems.
In fact, using additional agricultural technology could result in more than 13 billion tons of net negative greenhouse gas emissions each year as the world tries to avoid dangerous weather extremes.
“Our study recognizes that the food system is one of the most powerful weapons in the battle against climate change,” said Ronald B. Lynch Dean Holden, dean of Cornell University’s College of Agriculture and Life Sciences. We need to move beyond silver bullet thinking. Rapidly test, validate and scale local solutions by leveraging market-based incentives.”
The global network of food systems generates 21% to 37% of the planet’s greenhouse gas emissions each year. As the world population approaches 10 billion by mid-century, greenhouse gas emissions from the global food system — if left unchecked — could rise by 50-80% by 2050, the document says.
Previous research has indicated that changing food systems around the world is key to reducing greenhouse gases in the food system sector, but Houlton and Almaraz believe the emissions reductions could be much greater.
If the entire human population adopts a so-called “flexitarian” diet by 2050 — as recommended by the EAT-Lancet Commission (a global group of experts that established a nutritious, healthy and sustainable diet) — the scientists calculated the total reduction. 8,200 million metric tons of greenhouse gas emissions, which is below the net negative emissions target.
“Our study examines both dietary change and agricultural technologies as different options for dramatically reducing emissions,” said Almaraz, a Princeton University research associate.
Dietary changes have little effect on carbon sequestration, in contrast to the significant benefit of agricultural technology in causing massive negative emissions across the sector, according to the study, which included scientists from Kenya, Denmark, Malaysia and the UK.
“We have only analyzed a dozen technologies, but there are many more in development that are very promising for the food system,” Almaraz says.
The most effective way to reduce new model emissions is to promote soil amendments for crops (biochar, compost and rock amendments), improve agroforestry, promote sustainable shellfish harvesting practices and promote the production of hydrogen fueled fertilizers.
For example, in a process called “enhanced weathering,” silicate rock dust can be added to crop soils every five years to accelerate the formation of carbonates. This process absorbs carbon dioxide, which can sequester billions of metric tons of carbon a year, according to the paper.
Agroforestry, by planting trees on unused agricultural land, can sequester 10.3 billion metric tons of carbon per year, while growing algae on the ocean surface and then burying it in the deep sea can remove 10.7 billion metric tons of carbon dioxide.
Adding livestock feed could reduce methane emissions by 1.7 billion metric tons, and applying biochar to farmland could reduce nitrous oxide emissions by 2.3 billion metric tons.
Environmental action in the food system must start at the regional level. Houlton points out that anaerobic digesters have been converting manure from New York dairy farms into electricity since the mid-1970s, reducing emissions, supporting energy self-sufficiency and improving water quality.
Biogas from waste is converted into energy that can be easily used by local power companies, but this approach must prevent gas leakage and financial incentives are still needed. “We need a portfolio of solutions that are effective locally but have a global impact,” he says.
“If people choose to switch to healthier diets, if they can afford it, as the EAT-Lancet suggests, great,” says Houlton, “but it is imperative to avoid a climate that is too dangerous to transport negative greenhouse gas emissions to the world. Implications – We need to improve agricultural technology and management techniques To rely heavily on.
