Aug 14, 2025 09:31 PM
(This post was last modified: Aug 14, 2025 09:45 PM by C C.)
Climate models reveal human influence behind stalled pacific cycle
https://www.eurekalert.org/news-releases/1094690
INTRO: A new CU Boulder-led study has revealed that recent changes in North Pacific Ocean temperatures—long believed to be the result of natural variability—are in fact being driven by human-generated greenhouse gas and industrial aerosol emissions. These oceanic shifts are directly linked to the prolonged megadrought gripping the American Southwest, and this research published August 13th in Nature suggests it may not ease for another 30 years.
“Our results show that the drought and ocean patterns we’re seeing today are not just natural fluctuations—they’re largely driven by human activity,” said Jeremy Klavans, postdoctoral researcher in CU Boulder’s Department of Atmospheric and Oceanic Sciences and lead author of the study... (MORE - details, no ads)
The ‘deep root’ of the Anthropocene
https://www.marum.de/en/The-deep-root-of...ocene.html
PRESS RELEASE: 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.
PAPER: http://dx.doi.org/10.1029/2025GL114695
https://www.eurekalert.org/news-releases/1094690
INTRO: A new CU Boulder-led study has revealed that recent changes in North Pacific Ocean temperatures—long believed to be the result of natural variability—are in fact being driven by human-generated greenhouse gas and industrial aerosol emissions. These oceanic shifts are directly linked to the prolonged megadrought gripping the American Southwest, and this research published August 13th in Nature suggests it may not ease for another 30 years.
“Our results show that the drought and ocean patterns we’re seeing today are not just natural fluctuations—they’re largely driven by human activity,” said Jeremy Klavans, postdoctoral researcher in CU Boulder’s Department of Atmospheric and Oceanic Sciences and lead author of the study... (MORE - details, no ads)
The ‘deep root’ of the Anthropocene
https://www.marum.de/en/The-deep-root-of...ocene.html
PRESS RELEASE: 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.
PAPER: http://dx.doi.org/10.1029/2025GL114695