Mountain erosion, a process long thought to be reducing carbon dioxide in the atmosphere, is apparently doing the opposite, according to the findings of a new study.
The study, led by researchers from the Woods Hole Oceanographic Institution, claims that mountain erosion actually produces carbon dioxide. Does the discovery have any effect on our understanding of climate change?
Mountain Erosion Reduces Carbon Dioxide
According to the long-standing hypothesis, mountain erosion and rock weathering can pull the carbon dioxide from the air, as newly exposed rocks trigger reactions with the atmosphere in the formation of calcite and other minerals.
However, WHOI researchers claimed that mountain erosion actually releases more carbon dioxide into the atmosphere than what it absorbs. The study, published in the Science journal, added that the source of the carbon dioxide is not geological.
The carbon dioxide being produced during mountain erosion comes from microbes in the soil that consume the ancient sources of organic carbon that are trapped in the rock before they erode. As the microbes metabolize the minerals, they create carbon dioxide.
The researchers made the discovery while studying Taiwan's Central Range mountains, which are some of the most prone mountains to erosion worldwide. Upon examining the soil samples at the Central Range, they found almost no organic carbon. This is because the microbes were quickly consuming them.
The bacteria that are behind the carbon dioxide production have not yet been identified, but the researchers said that determining the bacteria is the next step of the study.
Will This Change Our Understanding Of Climate Change?
The findings on mountain erosion raise questions on whether this changes things for climate change.
While the reversal of the hypothesis on carbon dioxide reduction caused by mountain erosion was an unexpected one, the researchers claimed that it will not mean much for climate change. The amount of carbon dioxide released by mountain erosion in the atmosphere is small, compared with the carbon dioxide emission caused by humans. In addition, the process of mountain erosion happens over millions of years.
The findings of the study, however, will help better understand how the carbon cycles in mountains work. The researchers are also looking to determine how mountain erosion contributed to stabilizing the amount of carbon dioxide in the Earth's atmosphere over the past millions of years.
"It allowed Earth to have the climate and conditions it's had - one that has promoted the development of complex life forms," said lead author and Harvard University postdoctoral fellow Jordon Hemingway.