Terrestrial evidence for volcanogenic sulfate-driven cooling event ~30 kyr before the Cretaceous–Paleogene mass extinction


Summary

Researchers analyzed lignite samples from the Western Interior of the United States to reconstruct mean annual air temperatures (MAATs) leading up to the Cretaceous-Paleogene (K-Pg) boundary. They found a long-term warming trend of ~3°C over the last 100 kyr of the Cretaceous, followed by a transient cooling event of 2-5°C, coinciding with the peak of the Poladpur "pulse" of Deccan eruption ~30 kyr before the K-Pg boundary.

Highlights

  • Reconstructed MAATs using the MBT'5me proxy calibration developed for peats.
  • Found a long-term warming trend of ~3°C over the last 100 kyr of the Cretaceous.
  • Identified a transient cooling event of 2-5°C, coinciding with the peak of the Poladpur "pulse" of Deccan eruption.
  • The cooling event was likely caused by the aerosolization of volcanogenic sulfur.
  • Temperatures returned to pre-event values before the mass extinction.
  • The study suggests that volcanogenic climate change was not the primary cause of K-Pg extinction.
  • The findings support both models of climate change induced by Deccan volcanism.

Key Insights

  • The study provides the first terrestrial evidence for a transient cooling event linked to Deccan volcanism, which was previously recognized in marine records.
  • The cooling event was likely caused by the conversion of volcanogenic sulfur into sulfate aerosols, which would have reflected sunlight and cooled the planet.
  • The long-term warming trend of ~3°C over the last 100 kyr of the Cretaceous was likely driven by Deccan CO2 emissions.
  • The study highlights the varying tempo of Deccan volcanism-induced climate change, with both longer-term warming and shorter-term cooling events.
  • The findings suggest that the primary cause of the K-Pg extinction was not volcanogenic climate change, but rather another factor, such as the Chicxulub meteorite impact.
  • The study emphasizes the utility of lignite and coal records as sensitive archives of deep-time terrestrial climate change.
  • The research provides a new perspective on the role of Deccan volcanism in shaping the Earth's climate and ecosystems during the Cretaceous-Paleogene transition.



Mindmap

Volcanogenic sulfate-driven cooling event found
Occurred 30 kyr before K-Pg boundary
Terrestrial Evidence
Tested models of volcanogenic air temperature change
Found long-term warming and transient cooling
Climate Change Models
Primary trigger for K-Pg mass extinction
Models suggest volcanic outgassing of carbon and sulfur
Deccan Volcanism
Reconstructed mean annual air temperatures
Found long-term warming of 3°C
Temperature Records
Transient cooling event of 2° to 5°C
Coincided with peak of Poladpur "pulse" of Deccan eruption
Cooling Event
Greenhouse effects of CO2 emissions
Organic carbon played minor role in warming
Causes of Warming
Volcanogenic sulfur emissions caused cooling
Aerosolization of sulfur led to cooling event
Sulfur Emissions
Ecological stress caused by rapid climate change
Not primary cause of K-Pg extinction
Environmental Impact
High-resolution terrestrial paleotemperature records
Provided new insights into K-Pg boundary event
Paleoclimate Records
High-precision geochronological model used
Constrained timing of Deccan eruptions and K-Pg boundary
Geochronology

Citation

O’Connor, L. K., Jerrett, R. M., Price, G. D., Lyson, T. R., Lengger, S. K., Peterse, F., & van Dongen, B. E. (2024). Terrestrial evidence for volcanogenic sulfate-driven cooling event ~30 kyr before the Cretaceous–Paleogene mass extinction. In Science Advances (Vol. 10, Issue 51). American Association for the Advancement of Science (AAAS). https://doi.org/10.1126/sciadv.ado5478

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