Drier savannas and grasslands store more climate-buffering carbon than previously thought

We still know so little about climate, the earth, our oceans, and our sun!

Global Warming is a hoax and Climate Change a religion! Climate models are largely junk!

"The study estimates that soils in savanna-grassland regions worldwide have gained 640 million metric tons of stored carbon over the past two decades.

This is because over the last 20 years, fire suppression has led to smaller wildfires, and less burned area in drier savannas and grasslands. ...

The reduction in the size and frequency of wildfires in dryland savannas has led to an estimated 23% increase in carbon stored in topsoil. This increase was not foreseen by most of the state-of-the-art ecosystem models used by climate researchers. As a result, the researchers say, the climate-buffering impacts of dryland savannas are likely to have been underestimated. ...

But in more humid savanna-grassland regions covering 533,000 square miles (1.38 million square kilometers), more frequent wildfires and increased burned area resulted in an estimated 25% loss in soil carbon over the past two decades.

The net change during that time was a gain of 0.64 petagrams, or 640 million metric tons, of soil carbon. ..."

From the abstract:

"The determinants of fire-driven changes in soil organic carbon (SOC) across broad environmental gradients remains unclear, especially in global drylands. Here we combined datasets and field sampling of fire-manipulation experiments to evaluate where and why fire changes SOC and compared our statistical model to simulations from ecosystem models. Drier ecosystems experienced larger relative changes in SOC than humid ecosystems—in some cases exceeding losses from plant biomass pools—primarily explained by high fire-driven declines in tree biomass inputs in dry ecosystems. Many ecosystem models underestimated the SOC changes in drier ecosystems. Upscaling our statistical model predicted that soils in savannah–grassland regions may have gained 0.64 PgC due to net-declines in burned area over the past approximately two decades. Consequently, ongoing declines in fire frequencies have probably created an extensive carbon sink in the soils of global drylands that may have been underestimated by ecosystem models."

Drier savannas and grasslands store more climate-buffering carbon than previously thought | University of Cambridge Savannas and grasslands in drier climates around the world store more carbon than scientists previously thought and are helping to slow the rate of climate warming, according to a new study.

Soil carbon storage capacity of drylands under altered fire regimes (open access)

Extended Data Fig. 1: Distribution of semi-arid regions and savannah-grasslands.