170 Bison Herd Could Offset CO2 Equal To 2 Million Cars, Study Finds

Researchers studying European bison in Romania have found that these large herbivores may be a powerful tool in the fight against climate change. A herd of just 170 bison could store an amount of carbon dioxide (CO2) equivalent to taking nearly 2 million cars off the road for a year, according to a new model developed by scientists at the Yale School of the Environment.

The study, which has not yet been peer-reviewed, highlights the importance of wildlife conservation in maintaining healthy ecosystems. The model calculates the additional CO2 that animals like bison help capture and store in the soil through their natural behaviours.

"Bison influences grassland and forest ecosystems by grazing grasslands evenly, recycling nutrients to fertilise the soil and all of its life, dispersing seeds to enrich the ecosystem, and compacting the soil to prevent stored carbon from being released," explained lead author Professor Oswald Schmitz of Yale to The Guardian.

"These creatures evolved for millions of years with grassland and forest ecosystems, and their removal, especially where grasslands have been ploughed up, has led to the release of vast amounts of carbon. Restoring these ecosystems can bring back balance, and 'rewilded' bison are some of the climate heroes that can help achieve this."

Alexander Lees, a reader in biodiversity at Manchester Metropolitan University who was not involved with the study, said it "makes a convincing case for European bison reintroduction as a nature-based climate solution-one with major biodiversity conservation co-benefits.".

The research team studied a herd of European bison reintroduced to Romania's Arcu Mountains in 2014. The species had been absent from the region for nearly 200 years, but today the Arcu Mountains boast one of the largest free-roaming bison populations in Europe.

Oswald Schmitz, the lead author of a recent study, previously estimated that protecting and restoring just nine types of animals-marine fish, whales, sharks, gray wolves, wildebeest, sea otters, musk oxen, African forest elephants, and American bison-could result in the capture of an additional 6.4 billion tons of carbon dioxide annually. This amount is roughly equivalent to the yearly emissions of the United States.