idw – Informationsdienst Wissenschaft

Nachrichten, Termine, Experten

Grafik: idw-Logo
Science Video Project
idw-Abo

idw-News App:

AppStore

Google Play Store



Instanz:
Teilen: 
20.09.2022 12:20

Geoengineering Could Destabilize Tropical Peat Soils

Kai Uwe Bohn Hochschulkommunikation und -marketing
Universität Bremen

    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


    Originalpublikation:

    https://doi.org/10.1038/s43247-022-00544-0


    Bilder

    Measurements being performed on the Maludam, a tropical peat-draining river in Malaysia. The typically dark color of the water indicates a high levels of dissolved carbon, which is why peat-draining rivers are also known as blackwater rivers.
    Measurements being performed on the Maludam, a tropical peat-draining river in Malaysia. The typical ...
    Alexandra Klemme
    Alexandra Klemme University of Bremen


    Merkmale dieser Pressemitteilung:
    Journalisten, Lehrer/Schüler, Studierende, Wirtschaftsvertreter, Wissenschaftler, jedermann
    Biologie, Geowissenschaften, Meer / Klima, Physik / Astronomie, Umwelt / Ökologie
    überregional
    Forschungsergebnisse, Forschungsprojekte
    Englisch


     

    Measurements being performed on the Maludam, a tropical peat-draining river in Malaysia. The typically dark color of the water indicates a high levels of dissolved carbon, which is why peat-draining rivers are also known as blackwater rivers.


    Zum Download

    x

    Hilfe

    Die Suche / Erweiterte Suche im idw-Archiv
    Verknüpfungen

    Sie können Suchbegriffe mit und, oder und / oder nicht verknüpfen, z. B. Philo nicht logie.

    Klammern

    Verknüpfungen können Sie mit Klammern voneinander trennen, z. B. (Philo nicht logie) oder (Psycho und logie).

    Wortgruppen

    Zusammenhängende Worte werden als Wortgruppe gesucht, wenn Sie sie in Anführungsstriche setzen, z. B. „Bundesrepublik Deutschland“.

    Auswahlkriterien

    Die Erweiterte Suche können Sie auch nutzen, ohne Suchbegriffe einzugeben. Sie orientiert sich dann an den Kriterien, die Sie ausgewählt haben (z. B. nach dem Land oder dem Sachgebiet).

    Haben Sie in einer Kategorie kein Kriterium ausgewählt, wird die gesamte Kategorie durchsucht (z.B. alle Sachgebiete oder alle Länder).