How global warming sparked biggest mass extinction in history of Earth’s life

By Mark Waghorn via SWNS

Global warming sparked the biggest mass extinction in the history of life on Earth, according to new research.

More than 90 percent of marine species and over two-thirds of land animals were wiped out 250 million years ago - setting the stage for the rise of the dinosaurs.

The ecological disaster has implications for climate change today.

An analysis of fossilized plants preserved in rocks identified sunscreen-like chemicals in pollen.

It reveals UV (ultraviolet) radiation played a part. The exact causes behind the "Great Dying" have been much debated. Scientists say it is a warning for humanity.

Co-author Professor Barry Lomax, of the University of Nottingham, explained: "Plants require sunlight for photosynthesis but need to protect themselves and particularly their pollen against the harmful effects of UV-B radiation.

"To do so, plants load the outer walls of pollen grains with compounds that function like sunscreen to protect the vulnerable cells to ensure successful reproduction."

The catastrophic loss of biodiversity was a response to a climate emergency sparked by volcanic eruptions.

They released huge amounts of carbon into the atmosphere - generating severe warming and collapsing in the ozone layer.

The study in the journal Science Advances found an abundance of malformed spores and pollen grains that testify to an influx of mutagenic UV irradiation.

Lead author Professor Liu Feng of Nanjing Institute of Geology and Palaeontology in China, said: "We have developed a method to detect these phenolic compounds in fossil pollen grains recovered from Tibet.

"We detected much higher concentrations in those grains that were produced during the mass extinction and peak phase of volcanic activity."

The Permian-Triassic mass extinction bears parallels to what's happening to the planet now.

A sixth mass extinction has already started, with species disappearing at unprecedented rates - unlike anything seen in tens of millions of years.

Overconsumption, unsustainable practices and the release of greenhouse gases from the burning of fossil fuels are altering our life-sustaining climate at a dangerous pace.

Elevated UV-B levels can have far-reaching and long-lasting impacts on the entire Earth system.

Recent modeling studies show they reduce plant biomass and terrestrial carbon storage - which would exacerbate global warming.

Phenolic compounds are produced in the acid of plants. Increased concentration also makes tissue less easily digestible.

It would make a hostile environment even more challenging for herbivores, say the international team.

Dr. Wes Fraser of Oxford Brookes University said: "Volcanism on such a cataclysmic scale impacts on all aspects of the Earth system, from direct chemical changes in the atmosphere, through changes in carbon sequestration rates, to reducing volume of nutritious food sources available for animals."

Experts say historical episodes like this flag up what can happen when ecosystems change too fast for life to keep up.

Currently, CO2 in the atmosphere is increasing 100 times faster than it naturally should. The planet is warming ten times quicker than in the last 65 million years.

Oceans are acidifying 100 times faster with 'oxygen dead zones' increasing tenfold since 1950.

Given the similarities and what is at stake today, digging into the causes and impacts of the Great Dying can open up a window into a possible dire future.

It may also elucidate what urgent action is needed to avoid ecosystem and societal collapse.