Changing your diet in 3 key ways could fundamentally affect climate change

Climate change — and what to do about it — is an overwhelming problem.

And for some, it can seem like small gestures don't make much of a difference against the rising tide of issues that climate change causes around the globe.

But in two new studies published this week, scientists identify three key ways we can do something to impact climate change for good.

Together, the pair of studies lay out how humans have altered land use, and the major food changes we can make — both to our agricultural and food production systems and our individual behavior — that will ultimately work to protect the planet.

Changes the scientists are calling for involve 3 steps:

1. Creating more efficient and sustainable food production and trade
2. Reducing food waste
3. Following more eco-friendly diets, including eating fewer animal products

But shifting our diets and systems toward sustainable eating will take a significant uptick in the amount of effort we're putting in, the researchers say. And some will need to do more work than others. The researchers argue that people living in medium- and high-income countries are best poised to make these major changes, without sacrificing health.

Eating differently — Both new studies address the ways people can change their diets to benefit the environment. One study appeared on Monday in the journal Nature Sustainability. It looks at the ways our food systems are changing the climate.

The study authors found that food sourced from animals takes up 83 percent of the planet's agricultural land. In turn, all that farming cuts back on the amount of forest and natural vegetation in an area.

To get at solving the problem, the researchers suggest eating plant proteins — beans, nuts, lentils — in lieu of meat and dairy, as a way to bolster forests, which sequester carbon and curb climate change. That shift could theoretically remove as many as 16 years' worth of global carbon emissions from fossil fuels.

The researchers have ideas for which countries are best suited to make these sweeping changes.

"The greatest potential for forest regrowth, and the climate benefits it entails, exists in high- and upper-middle income countries, places where scaling back on land-hungry meat and dairy would have relatively minor impacts on food security," study lead author Matthew Hayek, an assistant professor at New York University, said in a statement.

Changes to diet also bore out in the second study, published on Wednesday in the journal Nature. In it, the research focuses on biodiversity.

As humans have pushed into natural places, species have suffered: Since 1970 alone, wildlife populations have dropped by an average of two-thirds, report the authors, which include the World Wildlife Fund.

The report uses computer models to show that global biodiversity's decline is set to continue if humans don't take more action toward protecting habitats.

In addition to changing the way we eat, reducing food waste and changing the way food is produced and traded are important for conservation, the researchers argue.

Food bridges environmental goals — The two studies focusing on wildlife and climate change meet at a point relevant to every living person: the food system.

Still, making dietary changes is only part of the plan.

In addition, researchers call for cutting fossil fuels and an energy system overhaul.

"We can think of shifting our eating habits toward land-friendly diets as a supplement to shifting energy, rather than a substitute," Hayek said. "Restoring native forests could buy some much-needed time for countries to transition their energy grids to renewable, fossil-free infrastructure."

Nature Sustainability Abstract: Extensive land uses to meet dietary preferences incur a ‘carbon opportunity cost’ given the potential for carbon sequestration through ecosystem restoration. Here we map the magnitude of this opportunity, finding that shifts in global food production to plant-based diets by 2050 could lead to sequestration of 332–547 GtCO₂, equivalent to 99–163% of the CO₂ emissions budget consistent with a 66% chance of limiting warming to 1.5 °C.

Nature Abstract: Increased efforts are required to prevent further losses to terrestrial biodiversity and the ecosystem services that it provides1,2 . Ambitious targets have been proposed, such as reversing the declining trends in biodiversity3 ; however, just feeding the growing human population will make this a challenge4 . Here we use an ensemble of land-use and biodiversity models to assess whether—and how—humanity can reverse the declines in terrestrial biodiversity caused by habitat conversion, which is a major threat to biodiversity5 . We show that immediate efforts, consistent with the broader sustainability agenda but of unprecedented ambition and coordination, could enable the provision of food for the growing human population while reversing the global terrestrial biodiversity trends caused by habitat conversion. If we decide to increase the extent of land under conservation management, restore degraded land and generalize landscape-level conservation planning, biodiversity trends from habitat conversion could become positive by the mid-twenty-first century on average across models (confidence interval, 2042–2061), but this was not the case for all models. Food prices could increase and, on average across models, almost half (confidence interval, 34–50%) of the future biodiversity losses could not be avoided. However, additionally tackling the drivers of land-use change could avoid conflict with affordable food provision and reduces the environmental effects of the food provision system. Through further sustainable intensification and trade, reduced food waste and more plant-based human diets, more than two thirds of future biodiversity losses are avoided and the biodiversity trends from habitat conversion are reversed by 2050 for almost all of the models. Although limiting further loss will remain challenging in several biodiversity-rich regions, and other threats—such as climate change—must be addressed to truly reverse the declines in biodiversity, our results show that ambitious conservation efforts and food system transformation are central to an effective post-2020 biodiversity strategy.