London: The largest
study yet of the Permian-Triassic mass extinction, or the Great
Dying, ties it to catastrophic greenhouse gas emissions.
According to new research, staggering quantities of carbon dioxide
and methane gas, from the largest volcanic eruption sent
temperatures soaring, causing wildfires that destroyed forests and
turned fertile land into deserts. This eradicated 95 percent of
marine life and 70 percent of life on land.
With time, life was beginning to gain momentum on earth,
four-limbed vertebrates had started to diversify into groups that
included amphibians, reptiles and the primitive ancestors of
mammals, the journal Science reported.
The new research is based on a variety of dating techniques and
analysis of sedimentary rocks from China and Tibet. It pinpoints
the extinction event at 252.28 million years ago, the Telegraph
Scientists believe that it was set off by a massive eruption from
the Siberian Traps, a system of volcanoes in what is now Russia.
The whole event lasted less than 200,000 years, with most species
dying out over a period of 20,000 years.
"Our information narrows down the possibilities of what triggered
the massive extinction and any potential kill mechanism must
coincide with this time," said Charles Henderson, researcher,
University of Calgary in Canada.
Researchers said the timing and pace of the mass extinction
indicated that both land and marine ecosystems collapsed suddenly,
leading to continental aridity and widespread wildfires and rapid
"The geological record tells us that 'change' happens all the
time, and from this great extinction life did recover," Henderson