Rising CO2 Speeds the Growth of Grasses on the African Savanna

Rising CO2 Speeds the Growth of Grasses on the African Savanna - Yale E360

← →

Search Search

E360 Digest

August 21, 2026

Rising CO2 Speeds the Growth of Grasses on the African Savanna

Kruger National Park in South Africa. Åse Elin Langeland

On the arid African savanna, grasses are growing faster than they were a generation ago, boosted by rising levels of carbon dioxide from the burning of fossil fuels. That is the finding of a new study that warns that faster growth could fuel larger wildfires and alter the distribution of wildlife. Since the dawn of the industrial age, the amount of carbon dioxide in the atmosphere has grown by half, which is helping to speed photosynthesis and cause many plants to grow faster. The phenomenon, known as “carbon fertilization,” has been well documented in forests, and some experts believe it may be responsible for the greening of drylands around the globe. It was long assumed, however, that grasses on the African savanna gain little from the extra carbon dioxide, as they already employ a highly efficient form of photosynthesis. But researchers are now finding otherwise. An analysis of three decades of data gathered from experiments and observations across Kruger National Park in South Africa shows that rising carbon dioxide levels are prompting faster growth. Between 1989 and 2021, grass production rose by 28 percent, a shift that could not be explained by changes in rainfall, temperature, grazing, fire, or other drivers, according to the study, which was published in Nature. Researchers say that extra carbon dioxide is allowing grasses to use water more efficiently, which is helping them to grow more quickly, even through dry spells. Modeling suggests that savanna grasses will continue to benefit from the surplus carbon dioxide even as warming intensifies heat and drought. The faster growth brings new risks, however. Researchers say more grass means more fuel for wildfires. It also means more forage, which could boost the number of grazing animals. And there is no guarantee that the additional carbon drawn down by grasses will stay locked away. “The wider impact depends on where the extra grass ends up,” said lead author Kimberley Simpson, an ecologist at the University of Sheffield. “If it is eaten by animals or burned in fires, much of the carbon is quickly released back into the atmosphere.” ALSO ON YALE E360 After Decades of Drought, Water Is Rising in the African Sahel

E360 FILM CONTEST

A Bicycle Journey Across Brazil to Find a Vanishing Savanna

OPINION

For America’s Rarest Wildlife, Survival May Hinge on a Single Word

By Ted Williams

E360 Film Contest

Who Gets to Decide the Fate of a Pristine Alaskan Rainforest?

Rising CO2 Speeds the Growth of Grasses on the African Savanna

Related Articles

Incident with Github.com

(no title)

Scientists reverse brain aging, with a nasal spray

NHS apologises and admits Palantir have access to identifiable patient data

Cursor Origin