Ancient climate research links past ocean acidification to current trends

A research team led by Professor Li Mingsong from Peking University has provided new insights into the Paleocene-Eocene thermal maximum (PETM) and its impact on ocean chemistry.

The study, published in Nature Geoscience and titled “Coupled decline in ocean pH and carbonate saturation during the Paleocene-Eocene thermal maximum,” reconstructs ocean acidification during this ancient climate phenomenon. and shows similarities with current trends related to human CO2 emissions.

The Paleocene-Eocene Thermal Maximum (PETM) 56 million years ago was a massive carbon release event that led to rapid global warming and significant ocean acidification. This study highlights similarities with current climate change and emphasizes the need to understand past events to predict future impacts. The findings highlight the urgency of addressing human CO2 emissions to protect marine ecosystems, especially fragile regions like the Arctic.

ocean acidification

The research team used paleoclimate data assimilation (DA) and integrated proxy data and Earth system model simulations to reconstruct ocean carbonate chemistry. During PETM, atmospheric CO2 increased dramatically from 890 ppm to 1980 ppm. Acidification is most intense in high latitudes, similar to the current trend in the Arctic where aragonite saturation is decreasing.

PETM was caused by massive carbon emissions, causing rapid warming and ecosystem destruction. The ocean’s pH dropped by 0.46 units from 7.91 to 7.45, causing widespread disruption to marine life. Ocean acidification has wiped out 30% to 50% of benthic foraminifera, resulting in significant loss of marine biodiversity.

Current CO2 emissions are increasing faster than during the PETM period, threatening marine ecosystems and highlighting the need for urgent climate action.