Growing evidence suggests that volcanic eruptions and the high emission of gases and ash, although lasting only a few days, can impact the climate for years. One important effect is a disruption of the earth's radiative balance when the aerosol clouds created by the particulate matter absorb terrestrial radiation and scatter incoming solar radiation. Volcanic eruptions have now been linked to the Permo–Triassic mass extinction approximately 250 million years ago, when up to 90 % of marine species and 75 % of terrestrial vertebrates disappeared forever. The EU-funded DECRYPT project is studying ultraviolet (UV)-B-absorbing compounds in the fossil remains of pollen for evidence of elevated UV-B radiation that may be related to this near-annihilation of life on Earth. Enhanced understanding could be important to addressing the challenges of climate change facing us today.
The Permo–Triassic mass extinction (PTME) was the most catastrophic extinction in the last 541 million years. There is now a robust temporal link between the PTME and Siberian Traps volcanism, which injected massive amounts of greenhouse gases and hydrothermal organohalogens into the atmosphere. This likely caused acute disruption of the stratospheric ozone balance, resulting in elevated harmful ultraviolet radiation (UV-B, 280–315 nm), but to date this possible key driver of the near-annihilation of life remains unquantified. A growing body of research demonstrates that UV-B absorbing compounds (UACs) contained within fossil pollen act as a reliable, independent proxy for changes in solar irradiance.
In this project I will develop a cutting-edge interdisciplinary framework that integrates high-resolution palaeoecological, stratigraphic, and palaeobiological data with new biogeochemical signatures from Permo–Triassic pollen and spores. This project will deliver a case study for proof-of-concept to address my key research objective: understanding the drivers of terrestrial ecosystem collapse across the PTME. As this ancient extinction is similar in many respects to current, anthropogenically-forced global changes, improving our understanding of ecological breakdown in the past is crucial to address a major societal challenge facing humanity today: accurately contextualising the rate and magnitude of modern species losses, in order to best direct conservation efforts and preserve essential ecosystem services.
