A new study led by the University of Oxford has challenged the belief that natural rock weathering acts as a CO2 sink. Instead, the study suggests that it can actually be a significant source of CO2, comparable to volcanoes. These findings, published in the journal Nature, have important implications for climate change modeling.
Rocks contain a vast amount of carbon from the remains of ancient plants and animals. This means that the “geological carbon cycle” plays a role in regulating the Earth’s temperature.
During chemical weathering, rocks can absorb CO2 when certain minerals react with the weak acid in rainwater. This process helps counterbalance the continuous release of CO2 from volcanoes worldwide and is part of the Earth’s natural carbon cycle, which has sustained life on the planet for billions of years.
However, this new study has measured an additional natural process of CO2 release from rocks into the atmosphere. It has found that this process is as significant as the CO2 released by volcanoes globally. Currently, most models of the natural carbon cycle do not account for this process.
This process occurs when rocks that formed on ancient seafloors, where plants and animals were buried in sediments, are uplifted to the Earth’s surface, such as during the formation of mountains like the Himalayas or Andes. This exposes the organic carbon in the rocks to oxygen in the air and water, leading to the release of CO2. Therefore, weathering rocks could be a source of CO2, contrary to the commonly held belief that they act as a sink.
2023-10-04 23:48:02
Article from phys.org
