The Greatest Extinction Event in 66 Million Years? Contextualising Anthropogenic Extinctions

Area of Science:

• Paleontology
• Ecology
• Conservation Biology

Background:

• Biological communities face unprecedented change due to human activities.
• A high rate of vertebrate species extinction suggests a potential sixth mass extinction event.
• Past mass extinctions, like the Cretaceous-Paleogene event 66 million years ago, offer historical context.

Purpose of the Study:

• To compare the current extinction event's scale with past mass extinctions.
• To determine when Earth last experienced an extinction event of comparable magnitude.
• To assess if human activities are driving extinction rates to historically significant levels.

Main Methods:

• Literature review of extinction events over the last 66 million years (Cenozoic Era).
• Comparative analysis of extinction rates and magnitudes.
• Assessment of current biodiversity loss against geological records.

Main Results:

• The current extinction episode, while significant, has not reached the scale of the bolide impact 66 million years ago.
• The ongoing extinction likely surpasses most other Cenozoic extinction events in magnitude.
• The Eocene-Oligocene transition (34 million years ago) may rival the current event, but data remains uncertain.

Conclusions:

• The magnitude of the current extinction event is not yet comparable to the Cretaceous mass extinction.
• Human-driven extinction rates have likely exceeded most Cenozoic events.
• The future scale of this extinction event hinges on humanity's response and interaction with the biosphere.