As people’s incomes increase, they tend to switch from “starchy foods” such as cereals, potatoes and tubers to meat and dairy products. “You would think there would be huge cultural differences between human populations in different regions of the world,” said Thomas Tomich, a food systems economist at the University of California, Davis, who was not involved in the new paper. this model. “Have some, But what’s surprising is how nearly universal this change is: the rise in incomes, especially from the poor to the middle class, actually affects the consumption of livestock products by What are the people like?”
However, livestock and dairy products are particularly important to the climate conversation because they are such a large source of methane emissions. Ivanovich’s model shows that by 2030, ruminant meat alone could be responsible for a third of the warming associated with food consumption. Milk will account for 19% more and rice 23% more. Together, these three groups will be responsible for three-quarters of the warming from the global food system.
However, there is a silver lining: The team suggests we could avoid half of this warming by improving our food systems and diets. That starts with eating less cows and other ruminants—the less stomach ferment the better. New food technologies can certainly help, such as plant-based imitation meat like Impossible burgers or meats grown from cells cultured in the laboratory, also known as cellular agriculture. Researchers are also testing cow feed additives reduced methane in their burps.
In the field, rice growers can significantly reduce their methane emissions by switch between wetting and drying the field, instead of waterlogged plants. Researchers are also developing crops fix their own nitrogen, in an effort to reduce nitrous oxide emissions. (legumes do this automatically thanks to symbiotic bacteria that live in their roots.) One team has created rice plants. biofilm development acts as a home for nitrogen-fixing bacteria, thereby reducing the need for synthetic fertilizers. Producing such fertilizers is extremely energy intensive, so reducing our reliance on them will further reduce emissions.
But Ivanovich stressed that wealthy nations certainly cannot force economically developing nations to adopt a methane-conscious diet. In some parts of the world, a cow is simply food and milk, but for a subsistence farmer, it can be a labor or monetary animal. “What is really needed is no change to the composition of the diet that is culturally inappropriate and supportive of local production practices and how they contribute to food,” she said. economic livelihood.
Ivanovich’s 1 degree figure is an estimate, not a prophecy. For one thing, she can’t intricately model how new food and farming technologies could reduce emissions in the coming decades. And environmental scientist Adrian Leip, lead author of last year’s study IPCC report on climate mitigation, pointed out that while these technologies are promising, it’s unclear when—or how quickly—people will adopt them. “At a certain point, one of those technologies—I don’t know if it will be mobile agriculture or if it will be plant-based analogues—will be very cheap. It will be so delicious and nutritious that people will start thinking: Why would I eat an animal?“Leip, who was not involved in the new paper, said. “I believe it has to happen, because I really don’t see a good reason Are not happen. And so if social norms start to change, it can happen very quickly.”
Complicating matters further is an additional feedback loop: As the food system increases global temperatures, crops will experience more heat stress than ever before. More severe drought. “This is really a dynamic interplay of two-way change, where the agriculture we produce affects our climate change, and our climate change,” says Ivanovich. we really influence how well we can produce crops and support our global population. “
But she offers a note of hope: Methane decrease rapidly once people stop producing it. It disappeared from the atmosphere after a decade, while CO2 lasted for centuries. “If we reduce emissions now, we will experience those reductions in future warming pretty quickly,” she said.
