Favoring plant-based proteins like those found in nuts, legumes, and grains over meat and dairy products could make drastic changes in how Earth's atmosphere accumulates carbon dioxide, research by Oregon State University finds.

The findings, published in the journal Nature Sustainability by OSU's William Ripple and experts at Harvard University, Colorado State University, and New York University explain how agricultural land aimed at producing animal-sourced food can put a strain on forests and other native vegetation well suited to absorbing CO2.

"Plant protein foods provide important nutrients while requiring a small percentage of the farm and ranch land needed to generate animal products like beef, pork and milk," said Ripple.

Through photosynthesis, trees and other plants produce energy from sunshine, water, and carbon dioxide, retaining some of the carbon in the form of wood, foliage, and oxygen releases.

According to research collaboration led by New York University's Matthew Hayek, the land needed to meet current global demand for meat and dairy-based products constitutes more than 80% of the Earth's agricultural acreage. If processing is moved to more land-friendly crops, the door opens up for the regrowth of natural vegetation capable of scrubbing away years of climate-changing fossil fuel pollution.

The researchers analyzed areas where substantial animal-sourced food production is likely to destroy the forests and other native vegetation. They identified areas amounting TO more than 7 million square kilometers - roughly Russia's size - with conditions such that forests will regenerate and flourish alone if agricultural stress was eliminated.

Atmospheric carbon dioxide has increased by 40% since the start of the industrial era, contributing heavily to a warmer world. According to the National Atmospheric and Oceanic Administration, the global average atmospheric carbon dioxide density in 2018 was 407.4 parts per million, higher than at any time in at least 800,000 years.

Fossil fuels like coal and oil contain carbon that plants have for millions of years taken out of the atmosphere by photosynthesis. In a matter of hundreds of years, the same carbon is added to the atmosphere when fossil fuels are used for oil.

According to NOAA, the average rate of rising atmospheric CO2 over the past six decades is around 100 times higher than changes occurring from natural causes, such as those that arose since the last ice age more than 10,000 years ago.

In comparison to oxygen or nitrogen, which compensates for much of the atmosphere, greenhouse gases steadily consume heat and emit it over time. If these greenhouse gases were not present, the average annual temperature of the planet would be below zero rather than around 60 degrees Fahrenheit, but the high amounts of greenhouse gases would allow the energy supply of the Earth to become unbalanced.

In comparatively affluent countries, the greatest opportunity for climate-benefiting forest regrowth lies. In those countries, reductions in meat and dairy production will have comparatively mild impacts on food security, the researchers add, while greatly helping to restrict climate change at 1.5 degrees Celsius over pre-industrial age levels as required by the Paris Agreement of 2016.

A majority of climate scientists believe that reducing warming to 1.5 degrees will conserve significant biodiversity proportions while improving human health and economies as well.