Toronto Star opinion writer
It's been interesting to read and follow everywhere about the supposed end of the world on Dec. 21. Of all the published pieces with their thoughts and explanations detailing how the Mayans may have earmarked 2012 and the 12th month and 21st day, the best I have seen really does present facts that there are good odds that our Earth as we know it very well could be destroyed again. It's happened before -- fossils prove it.
I watched a simulation documentary on TV once that explained the dinosaurs demise was a meteor, followed by a tsunami (drowning), followed by darkness and dust created by volcanoes and earthquakes, and finally no air to breath and no food to eat.
Anyway, here's the Toronto Star story:
()()()()()()()()()
Why worry about Mayan ‘apocalypse’? After all, bad things happened before
By Oakland Ross Toronto Star, Feature Writer
TORONTO -- Worried that the world will end today?
Join the club.
Most Canadians equipped with a brainwave pattern have probably heard by now that an ancient Mayan prophecy is being taken by some to mean that the apocalypse is nigh.
In fact, the end is (or was, if you are reading this later in the day) supposed to happen Dec. 21.
If accurate, the prediction is likely to put a significant damper on the festive season.
After all, even a cursory review of the scientific literature strongly suggests that the demise of a medium-sized, life-sustaining planet — were it to occur — would be a deeply unpleasant experience for most of its inhabitants
Not all the news is bad, however.
On the plus side, the fossil record clearly indicates that the Earth has tottered on the brink of outright destruction several times before, and our plucky little planet has managed to bounce back each and every time.
True, the recovery tends to take a while — up to 30 million years — so you would be wise to prepare for a wait. No harm in packing a sandwich or two, along with some light reading material. Try to use a flame-resistant container.
And remember this: should Armageddon occur, there’s a good chance that something will survive, even if it isn’t us.
After all, our wobbly blue planet has been down this parlous route before — this real-life video game of molten lava, wayward comets, and gamma ray bursts from outer space.
Among scientists, such natural hazards and their consequences are known as “mass extinctions.”
Although not exactly common, neither are they entirely rare. By some counts, serious mass extinctions have occurred at least 20 times since the Earth first incorporated itself from the cast-off material of stars, but most of those events were merely garden-variety catastrophes.
In order to qualify as a major mass extinction — at least in the minds of the scientific community — a particular disaster must result in the destruction of at least 50 per cent of the animal species that were resident on Earth when the asteroids crashed or the volcanoes blew.
It turns out that, during the 4.5-billion-year life span of the planet Earth, calamities on this scale have occurred precisely five times.
By far the most notorious such episode took place about 65 million years ago, and its principal consequence is probably familiar to anyone who has seen the movie Jurassic Park.
Known to experts as the Cretaceous-Tertiary extinction, this particular disaster may have been caused by a large asteroid striking the planet somewhere near the Yucatán Peninsula of present-day Mexico.
“By and large, the consensus is there was this one impact,” says Andrew Miall, a University of Toronto earth scientist.
As a result, almost all non-avian dinosaurs were destroyed, while roughly 70 per cent of all animal species were also wiped out, a cataclysm by any earthly standard.
But not the worst such setback this planet has suffered.
If we exclude the results of a certain Toronto mayoralty contest in 2010, the single worst catastrophe ever to befall our world was the Permian-Triassic extinction, which took place 251 million years ago and resulted in the permanent disappearance of 96 per cent of the planet’s animal species.
Ninety-six per cent.
The experts continue to debate the cause of that devastation — known to some as The Great Dying — but the main suspect is a huge “flood-basalt eruption” believed to have raged across much of what is now known as Siberia.
Think of this as a volcano on steroids.
A flood-basalt eruption causes a massive portion of the Earth’s crust to split apart, propelling vast quantities of molten lava to the surface and producing a blazing sea of fire that might easily burn, not for weeks or months or years, but for millions of years.
An event such as this may have triggered the Permian-Triassic extinction. Whatever its cause, the ensuing turmoil destroyed almost all life on the planet. Every creature that nowadays exists on Earth is descended from the 4 per cent of species that survived the smoke and horror of those times.
During the past 540 million years, the Earth has been struck by three other calamities on a comparable scale, all with catastrophic effects on the planet’s biodiversity — catastrophic but not quite terminal.
“There has been enough variety around that re-speciation proceeded fairly rapidly in geological terms,” says Miall at the University of Toronto.
What might seem “rapid” in geological terms counts as incomprehensibly slow by any other measure. Following the Permian-Triassic extinction, the planet’s trove of fauna eventually recovered its former complexity and variety, but it took about 30 million years.
This, to repeat, is the good news.
The bad news, according to many scientists, is that the Earth may now be perched at the threshold of a sixth mass extinction, a unique episode likely to unfold over the next three centuries or so.
Why unique?
Simple: this time the orgy of doom will result — not from huge tectonic shifts in the planet’s continental plates, or flood-basalt eruptions, or asteroid crashes — but from human activity instead.
Anthony Barnosky, a U.S. palaeobiologist cited recently by the British Broadcasting Corp., predicts that three-quarters of all extant mammal species will vanish during the upcoming 300 years, all victims of human activity and encroachment.
Such a disaster might not qualify as the end of the entire world, but it would surely spell a setback for some. Could it be that this is what the Mayans had in mind, except that their calculation was off by a century or two?
Or will our planet really come to an end today?
No comments:
Post a Comment