WELLINGTON: Soil, the top layer of “skin” on the Earth’s surface, might be produced at twice the speed previously thought, New Zealand scientists said on Friday, revealing research that could have implications for the battle against climate change.
Researchers from New Zealand’s Lincoln University and the University of Washington, in the U.S. made the discovery after testing soil samples from the western slopes of the South Island’s Southern Alps.
The findings were important as eroding mountainous regions accounted for more than half of the world’s sediment production, said a statement from Lincoln University.
If that sediment was produced by the formation of soil, rather than just slabs of bedrock collapsing off slopes as landslides, there was much greater potential for atmospheric carbon to be stored.
“This is significant because mountains play the role of carbon sinks — natural reservoirs that can accumulate and store atmospheric carbon,” it said.
The findings had implications for the global carbon cycle—a biogeochemical sequence of events whereby carbon as exchanged throughout the planet’s natural spheres. Higher soil production favored higher chemical weathering. The chemical weathering of the minerals in the soil used atmospheric carbon dioxide, thereby contributing to climate cooling.
Some scientists had previously suggested that with rapid uplift in mountains, soil production could not compete with landslides, so these landscapes lacked the soil chemical reactor needed to consume carbon dioxide.
The research showed that in the Southern Alps where rock was being pushed up at around 10 mm per year in places, which was considered rapid in geological terms, soils still formed fast enough to allow for good soil cover.
Lincoln University Associate Professor Peter Almond said the research raised new questions with regard to the rate of soil formation and chemical weathering in other mountainous regions around the world that displayed rapid geological uplifting.
“Since the dinosaurs became extinct our planet has cooled, and that cooling culminated in the ice age of the last 2.6 million years. Mountain uplift and its effect on soil weathering has fallen in and out of favor as one of the big contributors to the cooling. It might now be back in favor, though don’t look to mountains to save us from the massive amounts of fossil fuel carbon we are putting into the atmosphere,” he said in the statement. PNA