Context: The End-Permian Mass Extinction that killed 80% of life on Earth 250 million years ago may not have been quite as disastrous for plants, new fossils hint. Scientists have identified a refuge in China where it seems that plants weathered the planet’s worst die-off.

Background: –

• The end-Permian extinction is particularly interesting to scientists because it was driven by greenhouse gases, much like climate change today. The situation was far more extreme then: The polar ice caps melted completely — a situation that would cause sea levels to rise a staggering 230 feet (70 meters) today.

Key points

• The End-Permian Mass Extinction, also known as “The Great Dying”, is considered the most severe extinction event in Earth’s history.
• Occurring approximately 252 million years ago, it marked the boundary between the Permian and Triassic geological periods. This event led to the extinction of about 90% of all species, including 95% of marine species and 70% of terrestrial species.

The exact causes are still debated, but several factors likely contributed:

• Siberian Traps Volcanism: Massive volcanic eruptions in what is now Siberia released enormous amounts of lava and greenhouse gases (CO2 and methane). This led to global warming, ocean acidification, and environmental disruption.
• Climate Change: The release of greenhouse gases caused a dramatic increase in global temperatures, possibly by 8-10°C. This disrupted ecosystems and made many habitats uninhabitable.
• Ocean Anoxia: Warming oceans and changes in circulation led to widespread oxygen depletion in marine environments. This caused the collapse of marine ecosystems.
• Methane Hydrate Release: Warming may have triggered the release of methane hydrates from ocean sediments, further exacerbating global warming.
• Ozone Depletion: Volcanic emissions may have damaged the ozone layer, exposing life to harmful ultraviolet radiation.
• The recovery of ecosystems after the extinction was slow, taking 5-10 million years. The survivors, including early dinosaurs, mammals, and reptiles, diversified and eventually gave rise to new ecosystems in the Triassic Period.

Source: Live Science