A team led by LMU geologist Aaron Bufe has investigated how erosion and weathering affect the CO2 budget over millions of years.
A team led by LMU geologist Aaron Bufe has investigated how erosion and weathering affect the CO2 budget over millions of years.
For many hundreds of millions of years, the average temperature at the surface of the Earth has varied by not much more than 20° Celsius, facilitating life on our planet. To maintain such stable temperatures, Earth must have a ‘thermostat’ that regulates the concentration of atmospheric carbon dioxide over geological timescales, influencing global temperatures. The erosion and weathering of rocks are important parts of this ‘thermostat.’ A team led by LMU geologist Aaron Bufe and Niels Hovius from the German Research Centre for Geosciences has now modeled the influence of these processes on carbon in the atmosphere. Their surprising result: CO2 capture through weathering reactions is highest in low-relief mountain ranges with moderate erosion rates and not where erosion rates are fastest.
Weathering occurs where rock is exposed to water and wind. "When silicates weather, carbon is removed from the atmosphere and later precipitated as calcium carbonate. By contrast, weathering of other phases – such as carbonates and sulfides or organic carbon contained in rocks – releases CO2. These reactions are typically much faster than silicate weathering", says Hovius. “As a consequence, the impact of mountain building on the carbon cycle is complex.”
Read more at Ludwig-Maximilians-Universität München
Image: Aaron Bufe investigates the weathering of rocks. (Credit: © C. Trepmann via Ludwig-Maximilians-Universität München)
