idw – Informationsdienst Wissenschaft
Nachrichten, Termine, Experten
Nachrichten, Termine, Experten
The earth is warming up at an increasing rate. A contributing factor is carbon dioxide (CO2), a greenhouse gas, prompting researchers to investigate methods to reduce levels. In her dissertation at the University of Bremen, Dr. Alexandra Klemme discovered that the “enhanced weathering” strategy – which, until now, has been considered a promising method – is not suitable for removing CO2 from tropical peat soils. The research findings have now appeared in a renowned scientific publication.
What can we do to limit global warming? “Various strategies for extracting carbon dioxide (CO2) from the atmosphere are being discussed around the world. One of these methods is enhanced weathering,” explains Dr. Alexandra Klemme. She studied the effects of enhanced weathering on tropical peat soils as part of her PhD thesis, concluding that this approach is not suitable for reducing CO2 in these areas. Dr. Klemme conducted her research at the Institute of Environmental Physics at the University of Bremen (Dr. Thorsten Warneke, Professor Justus Notholt) in close cooperation with the Bremen-based Leibniz Centre for Tropical Marine Research (Dr. Tim Rixen) and Swinburne University in Malaysia (Dr. Moritz Müller). Her findings have now been published in the renowned nature research journal “Communications Earth & Environment.”
Why “Enhanced Weathering,” and Why Tropical Peat Soils?
Weathering is a natural process in which a chemical reaction binds CO2 with rock and water, thereby removing it from the atmosphere. “This happens extremely slowly, and a reduction in atmospheric CO2 is only noticeable when we look at the trend over thousands of years,” says Dr. Klemme. The enhanced weathering method involves crushing rocks into powder. “This increases the surface area where the chemical reaction takes place, which accelerates the weathering process. Spreading pulverized rock over land – for example agricultural land – is being discussed as a possible method for reducing atmospheric CO2.”
Warm and humid conditions further accelerate the weathering process, making tropical peatlands one of the possible target areas for enhanced weathering. About half of these peatlands are located in Southeast Asia. They store huge amounts of carbon and, in their natural state, absorb CO2 from the atmosphere. Today, a large proportion of these peatlands have been converted into agricultural land. “In most cases, this is associated with drainage and leads to peatland transforming from CO2 sinks into CO2 sources,” explains Dr. Klemme. It is hoped that using enhanced weathering in these regions will counteract these CO2 sources. “In addition, enhanced weathering would increase the pH value in the acidic soils. The agricultural industry would welcome this because it increases plant growth.”
Increased pH Value Destabilizes Peat Soils
However, this approach will not have the desired effect, because increasing the pH value through enhanced weathering would destabilize the peat soils. Beyond increasing CO2 emissions from peat soils, Dr. Klemme discovered that this technique resulted in more carbon leaching into rivers, thus raising CO2 emissions from rivers and coastal areas. The research was based on measurements from peat-draining river flows in Indonesia and Malaysia. The Institute of Environmental Physics, the Leibniz Centre for Tropical Marine Research, and Swinburne University have been taking the measurements over the past 10 years. The study shows that an increased pH value could lead to total CO2 emissions exceeding the expected CO2 uptake through enhanced weathering. “Therefore, this method can be ruled out,” says Dr. Klemme.
Original Publication:
Klemme A., Rixen T., Müller M., Notholt J., Warneke T. 2022, “Destabilization of carbon in tropical peatlands by enhanced weathering,” Communications Earth & Environment, https://doi.org/10.1038/s43247-022-00544-0
Contact:
Dr. Alexandra Klemme
Institute of Environmental Physics (IUP)
University of Bremen
Tel.: +49 421 218-62174
Email: aklemme@uni-bremen.de
https://doi.org/10.1038/s43247-022-00544-0
Measurements being performed on the Maludam, a tropical peat-draining river in Malaysia. The typical ...
Alexandra Klemme
Alexandra Klemme University of Bremen
Criteria of this press release:
Business and commerce, Journalists, Scientists and scholars, Students, Teachers and pupils, all interested persons
Biology, Environment / ecology, Geosciences, Oceanology / climate, Physics / astronomy
transregional, national
Research projects, Research results
English
Measurements being performed on the Maludam, a tropical peat-draining river in Malaysia. The typical ...
Alexandra Klemme
Alexandra Klemme University of Bremen
You can combine search terms with and, or and/or not, e.g. Philo not logy.
You can use brackets to separate combinations from each other, e.g. (Philo not logy) or (Psycho and logy).
Coherent groups of words will be located as complete phrases if you put them into quotation marks, e.g. “Federal Republic of Germany”.
You can also use the advanced search without entering search terms. It will then follow the criteria you have selected (e.g. country or subject area).
If you have not selected any criteria in a given category, the entire category will be searched (e.g. all subject areas or all countries).
