The Southern Andes, a tectonically active and volcanically rich mountain range, play a vital role in the global carbon cycle by acting as one of Earth’s natural long-term carbon sinks. Research conducted over the last decade indicates that this subcontinent-sized region sequesters approximately 1% of the world’s carbon dioxide (CO₂) emissions annually. This occurs through a natural process known as weathering. The Southern Andes have distinctive geological properties that store an important reservoir of CO₂ emissions. The sea-salt/organic balance has a major influence on atmospheric chemistry on a global scale.
Sheering storms In the Southern Andes, a slow weathering process is wearing down their shells. This breakdown sets off series of familiar chemical reactions that rapidly sequester CO₂ from the atmosphere. Weathering processes, including rainfall and glacial melt, continuously expose fresh rock surfaces. This exposure increases the weathering process as the rocks chemically react with water and air. Consequently, the Southern Andes are responsible for a significant fraction of global weathering fluxes and carbon sequestration.
Weathering Processes and Carbon Sequestration
The weathering processes that take place in the Southern Andes are rich and multifaceted. These processes result in millions of tons of carbon being pulled out of the atmosphere and stored in oceanic systems. Hydrothermal systems, like the famous hot springs that dot the Teton region, accelerate chemical reactions that boost CO₂ drawdown.
In the Southern Andes, silicate weathering export rates are more variable. They vary from 30 to 400 tons per square kilometer per year. This immense production speaks to the region’s ability to shape global carbon cycles. The natural weathering of silicate minerals works to bring CO₂ into solid form through chemical interactions, essentially combating atmospheric CO₂ build-up.
“Illustrative representation of weathering processes in the Southern Andes leading to carbon sequestration from the atmosphere and storage in the oceans.” – Peña-Echeverría et al, 2025
The interaction between geological activity and atmospheric conditions is key to understanding how these dynamic natural processes work. There is no hiding from the dynamic force of tectonic activity, which constantly exposes new rock. This opens up new surfaces as they are constantly created through weathering, increasing the region’s capacity for sequestering carbon.
The Role of Hydrology and Geography
Hydrological factors greatly influence the weathering processes active in the Southern Andes. Supplemental Figure S6 Hot water circulating through volcanic rock can more than double the silicate load of catchment rivers. This increase is part of a trend that is making the weathering process ever more effective at capturing atmospheric CO₂.
Rainfall and glacial melt are more than just easily measurable climatic changes. They literally eat away at the surface layer, unearthing ancient rock formations that play off of all sorts of ethereal elements. This long-term, dynamic process is what makes weathering a unique and powerful long-term climate regulator.
The Southern Andes hydrological system is deeply connected to its complex geography. The mountain range’s elevation and topography create unique microclimates. These conditions favor precipitation as well as glacial activity, which enhances the weathering process. From these interrelationships, researchers can collect informative insights. Learning this information has allowed them to more effectively estimate the impacts of climate change on this region’s ability to sequester carbon.
Global Implications of Southern Andes Weathering
The implications of weathering in the Southern Andes go well beyond regional boundaries, having important global ramifications. Rivers in this region export an estimated 0.0013 petagrams of carbon annually. This picture casts a clear light on the rivers’ integral role in carbon cycles across the globe.
Atmospheric CO₂ concentrations are increasing due to anthropogenic forces. More than ever is it important for us to learn from these natural mechanisms, particularly those well-represented throughout the Southern Andes. The consistent impact that this mountain range has on atmospheric chemistry underlines their importance as a natural climate change mitigation strategy.
“Relationship between the rates of silicate chemical weathering and CO2 consumption in the rivers of this study (red circles) and globally.” – Peña-Echeverría et al, 2025
Some of this research is still ongoing, probing into these Southern Andean weathering processes. Their research collects meaningful data, which inspires and informs broader strategies to combat carbon emissions around the world. The findings can provide valuable lessons on how to better harness natural processes to regulate climate.