Northern Hemisphere cooling 12,800 years ago generally thought to be caused by glacial meltwater; new geochemical evidence might support comet impact.

Analysis of ocean sediments has surfaced geochemical clues in line with the possibility that an encounter with a disintegrating comet 12,800 years ago in the Northern Hemisphere triggered rapid cooling of Earth’s air and ocean. Christopher Moore of the University of South Carolina, U.S., and colleagues present these findings in the open-access journal PLOS One on August 6, 2025.

During the abrupt cool-off—the Younger Dryas event—temperatures dropped about 10 degrees Celsius in a year or less, with cooler temperatures lasting about 1,200 years. Many researchers believe that no comet was involved, and that glacial meltwater caused freshening of the Atlantic Ocean, significantly weakening currents that transport warm, tropical water northward. In contrast, the Younger Dryas Impact Hypothesis posits that Earth passed through debris from a disintegrating comet, with numerous impacts and shockwaves destabilizing ice sheets and causing massive meltwater flooding that shut down key ocean currents.

However, the impact hypothesis has been less well supported, lacking any evidence from ocean sediments. To address that gap, Moore and colleagues analyzed the geochemistry of four seafloor cores from Baffin Bay, near Greenland. Radiocarbon dating suggests the cores include sediments deposited when the Younger Dryas event began. To study them, the researchers used several techniques, including scanning electron microscopy, single-particle inductively coupled plasma time-of-flight mass spectrometry, energy dispersive spectroscopy, and laser ablation inductively coupled plasma mass spectrometry.

The analysis detected metallic debris whose geochemistry is consistent with comet dust. These occurred alongside microscopic spherical particles whose composition indicates a mostly terrestrial origin, with some materials believed to be extraterrestrial—suggesting these microspherules could have formed when comet fragments exploded just above or upon hitting the ground, melting materials together. The analysis also uncovered even smaller nanoparticles with high levels of platinum, iridium, nickel, and cobalt, which can be signs of extraterrestrial origin.

Together, these findings indicate a geochemical anomaly occurring around when the Younger Dryas event began. However, they do not provide direct evidence supporting the impact hypothesis. More research is needed to confirm whether the findings are indeed evidence of impact, and to firmly link an impact to climate cooling.

Dr. Christopher R. Moore adds: “Our identification of a Younger Dryas impact layer in deep marine sediments underscores the potential of oceanic records to broaden our understanding of this event and its climatological impacts.”  

Dr. Mohammed Baalousha adds: “It is great to implement our unique nano-analytical tools in a new area of study, namely the analysis of nanoparticles generated or transported to the Baffin Bay core site during the Younger Dryas. We are always happy to implement our tools to support our colleagues and explore new frontiers.”

Dr. Vladimir Tselmovich adds: “Collisions of the Earth with comets led to catastrophes leading to climate change, to the death of civilizations. One of these events was a catastrophe that occurred about 12,800 years ago. Having studied in detail the microscopic traces of this disaster in Baffin Bay, we were able to find multiple traces of cometary matter, which was identified by the morphology and composition of the microparticles found. The amount of comet dust in the atmosphere was enough to cause a short-term “impact winter,” followed by a 1,400-year cooling period. The results obtained confirm the hypothesis that the Earth collided with a large comet about 12,800 years ago.”  

Citation: Moore CR, Tselmovich VA, LeCompte MA, West A, Culver SJ, Mallinson DJ, et al. (2025) A 12,800-year-old layer with cometary dust, microspherules, and platinum anomaly recorded in multiple cores from Baffin Bay. PLoS One 20(8): e0328347. https://doi.org/10.1371/journal.pone.0328347

From Fudan University and the “clustered climate science” department comes this inanity. They can’t show a trend in North Atlantic Hurricanes so they change the narrative to “clusters” of hurricanes. Of course, nobody could see such clusters before the satellite era, so what did they do? Make a “probabilistic framework” aka model of course – Anthony

Tropical cyclone cluster events over the North Atlantic. This image from NOAA’s GOES-16 satellite on September 14, 2020, shows five tropical systems spinning in the Atlantic basin at one time. From left to right: Hurricane Sally in the Gulf of Mexico, Hurricane Paulette east of the Carolinas, the remnants of Tropical Storm Rene in the central Atlantic, and Tropical Storms Teddy and Vicky in the eastern Atlantic. A total of 10 named storms formed in September 2020 — the most for any month on record. (Image credit: NOAA)

Tropical cyclones, commonly known as typhoons or hurricanes, can form in clusters and impact coastal regions back-to-back. For example, Hurricanes Harvey, Irma and Maria hit U.S. sequentially within one month in 2017. The Federal Emergency Management Agency failed to provide adequate support to hurricane victims in Puerto Rico when Maria struck because most rescue resources and specialized disaster staffers were deployed for the responses to Hurricanes Harvey and Irma.

A new study published in Nature Climate Change confirms these hurricane clusters are becoming more frequent in the North Atlantic in recent decades—a trend projected to continue in the near future.

Tropical cyclone clusters describe the event that two or more tropical cyclones present simultaneously within the same basin. This phenomenon is not rare, as historically only 40% of tropical cyclones appeared alone. Beyond the combined impacts of individual storms, tropical cyclone clusters can cause disproportionate damage as coastal communities and infrastructures need time to bounce back from the impact of the first storm. Understanding tropical cyclone clusters and their future is thus important for coastal risk management.

Analysing the historical observation of tropical cyclones, the authors found that during the past few decades, the chances for tropical cyclone cluster decreased in the Northwestern Pacific basin, while increased in North Atlantic basin. “We tried to develop a probabilistic framework to understand this trend” said Dazhi Xi, a climatologist at HKU who co-led the study and developed the methodology, “If tropical cyclone clusters are formed by chance, then only storm frequency, storm duration, and storm seasonality can impact the chance. So, as a first attempt we simulate the formation of tropical cyclone clusters by probabilistic modelling, considering only these three mechanisms, and hoped we could find why tropical cyclone clusters changed in the past decades”.

However, the probabilistic model is only partly successful. For some years, it significantly underestimates the chance of tropical cyclone cluster. It is because some storms coexist with other storms not simply by chance, rather, they have physical linkage. “The previously seemed failed statistical model now soon becomes a powerful tool that can distinguish physical-linked tropical cyclone cluster with those by pure chance” said Wen Zhou, a climatologist at Fudan University and the corresponding author of the study. For those years that the probabilistic model fails, the authors find that synoptic scale waves, a series of train-like atmospheric disturbances, enhance the chance of tropical cyclone cluster formation.

The study further discovered that the La-Nina-like global warming pattern, characterized by slower warming in the Eastern Pacific compared to the Western Pacific, is the reason behind the observed shifts in tropical cyclone cluster hotspot. “The warming pattern not only modulates the frequency of tropical cyclones in the North Atlantic and Northwestern Pacific basins, but also impacts the strength of the synoptic scale waves, together causing the shift of tropical cyclone cluster hotspot from Northwestern Pacific to North Atlantic basin” said Zheng-Hang Fu, a PhD student at Fudan University who co-led the study.

The research establishes a probabilistic baseline model for investigating tropical cyclone cluster events and their underlying physical mechanisms. This framework not only explains the observed shift of tropical cyclone cluster hotspot from the Northwestern Pacific to the North Atlantic basin, but also provides a transferable methodology applicable to other ocean basins worldwide. Importantly, the authors identify the North Atlantic as an emerging hotspot for tropical cyclone clusters in recent decades. This finding calls for heightened attention from Atlantic coastal nations, urging them to develop proactive strategies against these compounding hazards.

References:

Fu, Z.H., D. Xi, S.-P. Xie, W. Zhou, N. Lin, J. Zhao, X. Wang, and J.C.L. Chan, 2025: Shifting hotspot of tropical cyclone clusters in a warming climate. Nature Climate Change, 15. https://doi.org/10.1038/s41558-025-02397-9