The geological record of ocean acidification

Area of Science:

• Paleontology
• Marine Biology
• Climate Science

Background:

• Ocean acidification poses severe risks to marine ecosystems.
• Laboratory and field studies have limitations in assessing long-term impacts.
• The geological record offers insights into past environmental changes and biotic responses.

Purpose of the Study:

• To review past geological events of ocean acidification and associated environmental changes.
• To compare past events with current projections of ocean acidification.
• To understand the long-term consequences of elevated atmospheric CO2 on marine calcifiers.

Main Methods:

• Review of geological records spanning the past 300 million years.
• Analysis of evidence for elevated atmospheric CO2, global warming, and ocean acidification.
• Examination of contemporaneous extinction and evolutionary turnover events.

Main Results:

• Several past geological events show evidence of increased atmospheric CO2, warming, and ocean acidification.
• Some of these events coincided with marine calcifier extinctions and evolutionary changes.
• No past event perfectly matches the projected speed and scale of current CO2-driven ocean chemistry disruption.

Conclusions:

• Past geological events provide valuable context for understanding ocean acidification.
• The current rate of CO2 release is unparalleled in Earth's history.
• Future impacts on marine carbonate chemistry and ecosystems may be more severe than previously understood.