... paper in the journal Nature suggested it was possible for a truly vast
amount of frozen methane to be released over just 10 years – a blink of an
eye in geological terms. ... This melted vast amounts of methane that had
been trapped in the permafrost and sea floor, causing temperatures to soar
even further to levels “lethal to most life on land and in the oceans”.
“Based on measurements of gases trapped in [the mineral] calcite, the
release of methane … is deemed the ultimate source and cause for the
dramatic life-changing global warming … observed at the end Permian.
“Global warming triggered by the massive release of carbon dioxide may be
catastrophic, but the release of methane from hydrate [its frozen state]
may be apocalyptic. ...
Earth's worst-ever mass extinction of life holds 'apocalyptic' warning
about climate change, say scientists - Ian Johnston, Environment
Correspondent - Runaway global warming saw the planet's average
temperature hit about double what it is today about 250 million years ago
- 24 March 2017
http://www.independent.co.uk/environment/earth-permian-mass-extinction-apocalypse-warning-climate-change-frozen-methane-a7648006.html
Researchers studying the largest-ever mass extinction in Earth’s history
claim to have found evidence that it was caused by runaway global warming
– and that the “apocalyptic” events of 250 million years ago could happen
again.
About 90 per cent of all the living things on the planet were wiped out in
the Permian mass extinction – described in a 2005 book called When Life
Nearly Died – for reasons that have been long debated by scientists.
Competing theories have been put forward, including meteor strikes, huge
volcanic eruptions and climate change.
Now a team of researchers from Canada, Italy, Germany and the US say they
have discovered what happened and that their findings have “an important
lesson for humanity” in how we deal with current global warming.
According to a paper published in the journal Palaeoworld, volcanic
eruptions pumped large amounts of carbon dioxide into the air, causing
average temperatures to rise by eight to 11°C.
This melted vast amounts of methane that had been trapped in the
permafrost and sea floor, causing temperatures to soar even further to
levels “lethal to most life on land and in the oceans”.
“Based on measurements of gases trapped in [the mineral] calcite, the
release of methane … is deemed the ultimate source and cause for the
dramatic life-changing global warming … observed at the end Permian.
“Global warming triggered by the massive release of carbon dioxide may be
catastrophic, but the release of methane from hydrate [its frozen state]
may be apocalyptic.
“The end Permian holds an important lesson for humanity regarding the
issue it faces today with greenhouse gas emissions, global warming, and
climate change.”
The paper said the average global temperature would have reached “well
above 29°C”. Today’s average is about 15°C.
“The emission of carbon dioxide from volcanic deposits may have started
the world onto the road of mass extinction, but it was the release of
methane from shelf sediments and permafrost hydrates that was the ultimate
cause for the catastrophic biotic event at the end Permian,” the
researchers added.
Professor Peter Wadhams, head of the Polar Ocean Physics Group at
Cambridge University, suggested a major methane pulse was possible.
However he said this would be “maybe not apocalyptic, but catastrophic”.
“If there were a large methane release, which is now possible because of
the instability of the methane hydrates underneath the Arctic continental
shelves, the off-shore waters, that could quite easily give rise to a very
large pulse,” Professor Wadhams said.Researchers studying the largest-ever
mass extinction in Earth’s history claim to have found evidence that it
was caused by runaway global warming – and that the “apocalyptic” events
of 250 million years ago could happen again.
About 90 per cent of all the living things on the planet were wiped out in
the Permian mass extinction – described in a 2005 book called When Life
Nearly Died – for reasons that have been long debated by scientists.
Competing theories have been put forward, including meteor strikes, huge
volcanic eruptions and climate change.
Now a team of researchers from Canada, Italy, Germany and the US say they
have discovered what happened and that their findings have “an important
lesson for humanity” in how we deal with current global warming.
According to a paper published in the journal Palaeoworld, volcanic
eruptions pumped large amounts of carbon dioxide into the air, causing
average temperatures to rise by eight to 11°C.
This melted vast amounts of methane that had been trapped in the
permafrost and sea floor, causing temperatures to soar even further to
levels “lethal to most life on land and in the oceans”.
“Based on measurements of gases trapped in [the mineral] calcite, the
release of methane … is deemed the ultimate source and cause for the
dramatic life-changing global warming … observed at the end Permian.
“Global warming triggered by the massive release of carbon dioxide may be
catastrophic, but the release of methane from hydrate [its frozen state]
may be apocalyptic.
“The end Permian holds an important lesson for humanity regarding the
issue it faces today with greenhouse gas emissions, global warming, and
climate change.”
The paper said the average global temperature would have reached “well
above 29°C”. Today’s average is about 15°C.
“The emission of carbon dioxide from volcanic deposits may have started
the world onto the road of mass extinction, but it was the release of
methane from shelf sediments and permafrost hydrates that was the ultimate
cause for the catastrophic biotic event at the end Permian,” the
researchers added.
Professor Peter Wadhams, head of the Polar Ocean Physics Group at
Cambridge University, suggested a major methane pulse was possible.
However he said this would be “maybe not apocalyptic, but catastrophic”.
“If there were a large methane release, which is now possible because of
the instability of the methane hydrates underneath the Arctic continental
shelves, the off-shore waters, that could quite easily give rise to a very
large pulse,” Professor Wadhams said. ...
...
--------
The Permian Collapse: 250 million years ago, long before dinosaurs roamed
the Earth, the land and oceans teemed with life. This was the Permian, a
golden era of biodiversity that was about to come to a crashing end.
Within just a few thousand years, 95% of the lifeforms on the planet would
be wiped out, in the biggest mass extinction Earth has ever known. What
natural disaster could kill on such a massive scale? It is only in recent
years that evidence has begun to emerge from rocks in Antarctica, Siberia
and Greenland.
The demise of the dinosaurs, 65 million years ago (at the so-called K/T
boundary), was nothing as compared to the Permian mass extinction. The K/T
event killed off 60% of life on Earth; the Permian event 95%.
The documentary features paleontologists and other scientists as they try
to find clues to the great extinction. It is argued that the Permian
extinction came in 3 stages; the first was caused by volcanic activity in
the great Siberian Traps. This is proposed to have caused global warming,
which in turn killed much of the life on land. Second, it warmed up the
sea, which killed much of the marine life. As the sea became warmer, the
ocean floor released a massive amount of methane. As the methane reached
the atmosphere, the earth became even warmer, which led to the extinction
of even more lifeforms on land. Here is a short preview:
The day the Earth nearly died (BBC), Documentary length: 49 min
http://www.youtube.com/watch?v=YNQdL5uQy90
