Ozone depletion and acid rain was responsible for the Permian extinction 250 million years ago, researchers find.
The mass extinction that took place at the end of the Permian era 250 million years ago is often referred to as the most traumatic species die-off in Earth's history. For years now, scientists have speculated over the reason for the extinction with many stating it was the contemporaneous volcanic eruptions in Siberia that caused it. However, a new study says that the extinctions were greatly affected by the atmospheric effects of these eruptions, according to a press statement.
Researchers from the Carnegie Institution conducted a study which tested the theory that held these eruptions responsible for the extinction. For this, they used 3-D modeling techniques to predict the impacts the gas released from the so-called Siberian Traps would have had on the atmosphere at the time.
Researchers found that the effects of these eruptions were catastrophic. The amounts of carbon dioxide and sulfur dioxide released during the volcanic eruptions were so large that it triggered highly acidic rain. This stripped the soil of its nutrients that led to the death of both plants and other vulnerable terrestrial organisms. Along with this, the halogen-bearing compounds such as methyl chloride that were also released created a global ozone collapse.
They also found that these volcanic eruptions were episodic and contributed majorly to acid rain and ozone depletion. This led researchers to conclude that the drastic fluctuations in pH and ultraviolet radiation, combined with an overall temperature increase from greenhouse gas emissions, could have contributed to the end-Permian mass extinction on land.
The Permian mass extinction was so severe that it led to the sudden loss of more than 90 percent of marine species and over 70 percent of terrestrial species. It can also be held responsible for paving the way for the rise of the dinosaurs. Due to the massive loss of bidiveristy, according to the fossil records, recovery took several million years. Nearly 10 million, according to some estimates.
