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Posted on 07/09/2009 11:19:06 AM PDT by BGHater
One fine day about 74,000 years ago, a giant volcano on Sumatra blew its top. The volcano, named Toba, may have ejected 1000 times more rock and other material than Mount St. Helens in Washington state did in 1980. In the process, it cooled the climate by at least 10°C, causing a global famine. But could the aftermath have been even worse? A new study puts to rest questions about whether Toba plunged Earth into a 1000-year deep freeze and whether an equivalent event today could jump-start a new, millennia-long ice age.
Giant volcanic eruptions such as Toba briefly cause the opposite of global warming. Although eruptions do emit greenhouse gases such as carbon dioxide, volcanoes also spew sulfur dioxide. Combined with water vapor, sulfur dioxide forms sulfate aerosols, which can spread around the globe, blocking solar radiation and chilling the air before becoming acid rain and snow.
Paleoclimate evidence suggests that the Toba eruption, which occurred during the last ice age, emitted lots of sulfur dioxide--vastly more than Mount St. Helens did. The eruption also seems to have coincided with the start of a 1000-year period of even colder temperatures. Some scientists have suggested that Toba caused the deep freeze and that perhaps such an event happening today could bring on a new ice age. But models developed by NASA and the National Center for Atmospheric Research in Boulder, Colorado, argue otherwise.
Researchers led by climatologist Alan Robock of Rutgers University in New Brunswick, New Jersey, ran scenarios that featured eruptions producing up to several times more sulfur dioxide than Toba. The result, published 27 May in the Journal of Geophysical Research—Atmospheres, was a cooler climate that lasted only a few decades. So the 1000-year cold spell was probably part of the natural cycle that has produced more than a dozen ice ages over the past couple of million years.
"The results virtually eliminate mega volcanic eruptions as one of the key drivers of global-scale glaciation," says climatologist Ellen Mosley-Thompson of Ohio State University in Columbus, who was not involved in the study. So, paleoclimatologists should focus on more likely climate coolers, she says, such as changes in ocean circulation or cyclical variations in Earth's orbit around the sun.
Still, if Toba erupted today like it did in the past, the results would be catastrophic. Although the volcano isn't expected to blow its top for thousands of years, Robock and colleagues estimate a megaeruption could lower global temperatures by as much as 17°C for several years, followed by a recovery to normal conditions that could take decades. That would hit the human population with the double whammy of dramatically reduced agricultural production and widespread loss of vegetation, leading to widespread food shortages and starvation.
Catastrophe, not our fault ping
Too bad Al Gore and Michael Moore weren’t around 74K years ago!
You know... Indonesia is really beginning to P*ss me Off!!
What is with all their volcanoes being so savagely destructive????
Krakatoa and now Toba and who knows what else!!!!
They need to come to the Big Island on Hawaii to see how nice well raised well behaved volcanoes behave!
Still, if Toba erupted today like it did in the past, the results would be catastrophic. Although the volcano isn't expected to blow its top for thousands of years, Robock and colleagues estimate a megaeruption could lower global temperatures by as much as 17°C for several years, followed by a recovery to normal conditions that could take decades. That would hit the human population with the double whammy of dramatically reduced agricultural production and widespread loss of vegetation, leading to widespread food shortages and starvation.
What you won't hear from the media or politicians today is that we're still in an Ice Age and warming should be the least of our concerns.
Can’t be true since the earth is much less than 74,000 years old. /sarcasm
One of the effects of this volcanic event was the elimination of all but a few thousand humans.
ping
Maybe Al Gore and Obama can build us one of these mo-fos to solve our overheatin’ issues. Yo.
:’) but alas...
Ancient Supervolcano’s Eruption Caused Decade Of Severe Winters
ScienceDaily | July 2, 2009 | Unknown
Posted on 07/03/2009 5:39:20 AM PDT by decimon
http://www.freerepublic.com/focus/chat/2284760/posts
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A thousand times as much as St. Helens?
Try TEN THOUSAND!!
Global temps crashed like 7-10 degrees Celsius for a thousand years, worldwide, human population is estimated to have fallen to about 5,000 individuals.
Unless I’m mistaken, this was the largest supervolcano event in like the last 500,000 years or so.
This is one of Blam’s faves, ask him about it.
Amazingly, the Hobbits on nearby Flores Island survived this catastrophe.
So why don’t you guys fight it out about the truth of the ‘Toba bottleneck’, and get back to the rest of us.
We were hoping you'd contribute something.
I don't mean to butt in here, but I will.
As one who has become increasingly suspicious, even cynical of output from the Scientific Community™, I suspect much of the snipe hunting by the Scientific Community™ is nothing more than an effort to keep the grant moneys flowing, primarily from Uncle Sugar. Consider there apparently has not been a concensus reached on something that happened in our own back yard ~12,000 years ago, that is, the extinction of the Northern Hemisphere's megafauna, along with a goodly number of humans probably, at least in North America. And this happened like, yesterday! The upshot I suppose is once concensus is reached the research dollars likely fall off to a trickle. Of course the proper concensus must be reached or the funds will flow until it happens. Again, call me cynical...
Not an expert, but what I’ve heard about genetic drift, implying that there was a real shortage of Homo sap. back in those years to be rather convincing, so would be interested in hearing it explained in some other way. Don’t really have an apeman in this fight!
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