Article Reflection: How to Kill (Almost) All Life: The End-Permian Extinction Event

A fossilized crinoid from Permian period.

Benton and Twitchett suggest that the End-Permian mass extinction was largely driven by massive volcanic eruptions in Siberia that disrupted Earth’s climate, according to Benton and Twitchett (2003). Their findings suggest that greenhouse gases from these eruptions caused severe global warming. One key piece of evidence they highlight is a sharp drop in carbon levels recorded in the rock layers from that time. Volcanic carbon dioxide by itself can’t explain the magnitude, but they propose that warming released methane from gas hydrates, creating a runaway greenhouse effect.

Figure 1. Sharp changes in carbon isotope values across the Permian–Triassic boundary, showing the major carbon cycle disruption linked to the mass extinction (Benton & Twitchett, 2003).

They also discuss the asteroid impact theory, which was a competing hypothesis at the time. Benton and Twitchett (2003) note that while some researchers pointed to iridium spikes or shocked minerals, this evidence was inconsistent or weak. On the other hand, accurate dating places the Siberian eruptions right at the extinction boundary. They further support their case with evidence of global temperature rise, ocean oxygen loss, and fossil data showing ecosystems collapsing rapidly in many regions.

What stood out to me was how the authors combined so many kinds of evidence into one story. I’m familiar with the End-Permian extinction event being that I am passionate about paleontology, but this paper educated me further on the evidence. The carbon isotope data gave me a better understanding of how past climate shifts are tracked. Overall, the paper helped me appreciate how interconnected Earth systems are (Benton & Twitchett, 2003).

Reference

Benton, M. J., & Twitchett, R. J. (2003). How to kill (almost) all life: The end-Permian extinction event. Trends in Ecology & Evolution, 18(7), 358–365.