The ‘deep root’ of the Anthropocene

The basis for the findings of the international team, which includes researchers from Germany, the Netherlands, and China, is a sediment core obtained in 2005 during an expedition with the research vessel SONNE in the Indian Ocean off the coast of East Java (Indonesia). Particles that are transported by rain into rivers and then into the sea accumulate on the ocean floor. These samples often contain unique information about the past that is preserved in the sediments for thousands of years.

This enabled them to demonstrate how soil erosion has changed and the reasons for this. To do this, they analyzed sediments dating back to 5,000 years. For the study, the team focused on molecular markers for soil erosion and fire events and compared them with reconstructions of vegetation and hydroclimate, i.e., humidity, in this region. They divided the past 5,000 years into periods in which soil erosion changed and compared them with the other parameters to find out what the respective driving factors were. It turned out that people in this region began cultivating the land around 3,500 years ago. Without any evidence of changing vegetation or hydroclimate, fire markers increased, indicating slash-and-burn practices to clear the land. “Such early farming practices likely made soils more susceptible to erosion,” explains lead author Yanming Ruan. This is a clear signal of human influence on nature – much earlier than researchers had previously thought.

Dr. Enno Schefuß from MARUM adds: "In order to assess the influence of humans on the climate and environment, one must compare the current situation with an uninfluenced period. Our results show that we need to look back much further. In this case, we are talking about the ‘deep root of the Anthropocene’, i.e. the period in which humans have had a major impact on the natural environment and climate."

According to Ruan, the data also show that the permanent, more intensive agriculture has led to the most severe soil erosion in around 500 years. This has been exacerbated by intense monsoon rains. In the future, progressive global warming could lead to more frequent and heavier rainfall in Indonesia. According to the study's conclusion, this could further accelerate erosion rates in the future, posing risks to natural resources.

 

Original Publication:

Yanming Ruan, Mahyar Mohtadi, Lydie M. Dupont, Dierk Hebbeln, Sander van der Kaars, Wenwen Chen, Ellen C. Hopmans, Stefan Schouten, Matthias Prange, Jens Hefter, Gesine Mollenhauer, Enno Schefuß: Late Holocene human impact on tropical soil erosion in the Maritime Continent. Geophysical Research Letters 2025. DOI: 10.1029/2025GL114695 [http://dx.doi.org/10.1029/2025GL114695]

Contact:

Dr. Yanming Ruan
Organic Geochemistry
Eail: yruan@marum.de

Dr. Enno Schefuß
Molecular Paleoclimatology
Email: eschefuss@marum.de

 

Participating institutions:

• MARUM – Center for Marine Environmental Sciences and Faculty of Geosciences, University of Bremen
• NIOZ Royal Netherlands Institute for Sea Research, Department of Microbiology and Biogeochemistry, Texel (Netherlands)
• State Key Laboratory of Marine Geology, Tongji University (China)
• School of Earth, Atmosphere and Environment, Monash University (Australia)
• Cluster Earth & Climate, Department of Earth Sciences, Faculty of Sciences, Vrije Universiteit Amsterdam (Netherlands)
• Department of Palynology and Climate Dynamics, Albrecht-von-Haller Institute for Plant Sciences, University of Göttingen
• Editorial Office of Journal of Ocean University of China (China)
• Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) Bremerhaven
• Department of Earth Sciences, Utrecht University (Netherlands)

 

MARUM produces fundamental scientific knowledge about the role of the ocean and the ocean floor in the total Earth system. The dynamics of the ocean and the ocean floor significantly impact the entire Earth system through the interaction of geological, physical, biological and chemical processes. These influence both the climate and the global carbon cycle, and create unique biological systems. MARUM is committed to fundamental and unbiased research in the interests of society and the marine environment, and in accordance with the Sustainable Development Goals of the United Nations. It publishes its quality-assured scientific data and makes it publicly available. MARUM informs the public about new discoveries in the marine environment and provides practical knowledge through its dialogue with society. MARUM cooperates with commercial and industrial partners in accordance with its goal of protecting the marine environment.

 

 

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