Surprising enough, nobody has brought up the latest theory for the mass extinction of mega-fauna in North America at the end of the last ice age, and the cause for the Younger Dryas. What I am talking about is the latest evidence leading to the theory, which is still theory, that a comet Impactor exploded in the upper atmosphere, causing the end of Clovis culture, and a large portion of fauna on the North American Continent.

In order to stimulate discussion on this interesting topic, I will post what I have recently written at Ai-Jane.org (http://www.ai-jane.org/forums/viewtopic.php?t=8249). I know that we all have our own idea as to what is vitally important to this planet and humans, but the thought of millions, even billions, of humans dying off immediately as a result of a large comet, or asteroid, leaves me very unsettled. In fact, this dwarfs the 'so called' thread of a warming planet, so much so that to be worried about the later, at the expense of the former, seems to be intellectual laziness 'par excellence'
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For many years now, the mystery of the vanishing fauna in post Pleistocene North America, has stumped paleontologists. How did so many species suddenly disappear. And this ranges from the giant bison, ground sloth, dire bear, smilidon, North American horse, mammoth, and many others.

Theories have ranged from viruses to human interaction, to haitat change. Yet none of them have really been carried the day, as all have been a real stretch of imagination. As a graduate student I have always believed that there had to be something other than invading humans responsible, because the diversity of extinctions and their suddenness just did not add up.

Now there is a new theory out, and it does not rely upon any of the above causes. This one is celestial in nature, and is currently under close scrutiny. It's also a new theory, having just been raised in 2007, so it will be disputed for years to come. But it makes sense, just as mass extinctions in the past, have almost all been the result of celestial Impactors as well.

As an anthropologist, I find this spellbinding, because the implications are Huge. The prospect of random Impactors, capable of causing such disruption, adds to the threat of cyclical Inpactors which can cause even more damage and extinction rates. In other words, the longer we continue to keep all of our eggs in one single basket, the greater the odds that we too will be made extinct by some Impactor in the future.

New Clovis-Age Comet Impact Theory (http://www.newswise.com/articles/view/530208/)

Newswise — Two University of Oregon researchers are on a multi-institutional 26-member team proposing a startling new theory: that an extraterrestrial impact, possibly a comet, set off a 1,000-year-long cold spell and wiped out or fragmented the prehistoric Clovis culture and a variety of animal genera across North America almost 13,000 years ago.

Driving the theory is a carbon-rich layer of soil that has been found, but not definitively explained, at some 50 Clovis-age sites in North America that date to the onset of a cooling period known as the Younger Dryas Event. The sites include several on the Channel Islands off California where UO archaeologists Douglas J. Kennett and Jon M. Erlandson have conducted research.



For a more detailed and close examination of the theory, you can read more here: THE CLOVIS COMET Part I: Evidence for a Cosmic Collision 12,900 Years Ago (http://allendale-expedition.net/publications/comet.pdf)

About Comets vs Asteroids

The thing that leaves me scratching my head is the frequency with which commentators, and even scientists use "asteroids" and "comets" so interchangably. There is a big difference, and an impact by one will not be akin to that of another.

Usually, the 'so called' experts will tell everyone that the dinosaurs were killed off 65 million years ago, by a huge asteroid. But the odds of that are very small, and a comet is a 90% certainty. Comets streak around the solar system at two to three times the velocity of asteroids. This means that the kenetic energy of a comet is far greater, and the time from atmosphere to impact will be much less, even coming in at a 30 degree angle, which is what the dinosaur killer most likely entered the atmosphere.

Also, comets are almost always much bigger than asteroids. Some of them are simply Huge, and if they were to Impact the earth, they would do far more damage than the 6 mile comet that struck 65 million years ago.

But the theory here of an air burst leads me to think that this may have been an asteroid, or a very loose, and small comet. It's hard to tell, but I have not read about any evidence of iridium as of yet. Comets will give off more iridium debris, so we shall have to wait and see what the debris layer shows on this.

But I am fairly certain that an Impactor is the reason for the mass extinction of certain fauna in North America . As a matter of fact, it is starting to look like ALL mass extinctions are the result of celestial intervention. This is why I am amazed with the Eco-Wackos's hysteria about something as benign as global warming, and totally oblivious to the REAL DANGER, which lies out in the Ort Cloud and Kuiper Belt. All it takes is for one of these Impactors to give us a personal visit, and we are Truely Screwed, Blued, and tatooed.

Here are a couple more schollarly publications on the topic.

Evidence for an extraterrestrial impact 12,900 years ago that contributed to the megafaunal extinctions and the Younger Dryas cooling (http://www.pnas.org/cgi/content/full/104/41/16016)

Younger Dryas "black mats" and the Rancholabrean termination in North America, by C. Vance Haynes, Jr* (http://www.pnas.org/cgi/doi/10.1073/pnas.0800560105)

Exploding Asteroid Theory Strengthened by New Evidence Located in Ohio, Indiana
Was the course of life on the planet altered 12,900 years ago by a giant comet exploding over Canada? New evidence found by UC Assistant Professor of Anthropology Ken Tankersley and colleagues suggests the answer is affirmative.

Read more (http://www.uc.edu/news/NR.asp?id=8625)

Read more (http://www.uc.edu/news/NR.asp?id=8625)

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>>Read less

Well, i thought it was funny.
i don't know too much about it, but even i can figure out that the deposits as related to glacial activity.

“For several months following the comet strike, the skies rained precious stone and metals, the researchers speculate. Diamonds drizzled down by the tons.“

Source (http://www.livescience.com/strangenews/080707-canada-diamonds.html)

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>>Read less

Well, i thought it was funny.
i don't know too much about it, but even i can figure out that the deposits as related to glacial activity.

No, you misunderstood.
Orleander is just stating her personal life philosophy :D
The full version is: "Read less, ask more".

Mmmmm.... maybe 2012 AD seems more plausible... ask me if you want to know why...

The comet may have been responsible for much more than the extinctions mentioned. The Laurentide ice sheet was several miles thick and covered a vast area of North America. An airburst of this magnitude could have melted hundreds of cubic miles of ice more or less instantly. In the process, it would have vaporized cubic miles of melt water super-saturating the Earth’s atmosphere. The ice sheet was thousands of feet in height. The out-rush of water from the former ice sheet would have created a mega flash flood of vast height and proportion. In many areas it could have been well over a thousand feet in height and hundreds of miles wide. As the mega flood rushed from the Colorado Plateau to the Gulf of Mexico, it would have carved out hundreds of miles of landscape on an unbelievable scale. This could account for many of the spectacular canyons, mesas and other land formations now visible in the American Southwest.
As hundreds of cubic miles of water reached the Gulf of Mexico, it would have caused sea levels to rise hundreds of feet world wide. For those who entertain such ideas, this could also account for Plato’s legend of Atlantis. Plato wrote that Atlantis sunk into the sea during a day and a night of unbelievably torrential rainfall. What might have actually happened was that the super saturated atmosphere released it’s water vapor within a very short time span creating unprecedented epic level rainfall around the globe. As global sea levels suddenly rose, the survivors of Atlantis would have been unable to distinguish this from their island sinking into the sea.
Mega event theories have, until the last few years, been viewed with disdain by the scientific community. Now, however, many such mega events have come to light such as the Montana scablands mega flood, the catastrophic flooding of the Black Sea the super volcano about 70,000 years ago that wiped out about 99% of the human gene pool and many others.
We now know that the slow and gradual processes, that we previously thought shaped the Earth alone, have been punctuated again and again by many mega events of unimaginable proportions.

[size="2"] In fact, this dwarfs the 'so called' thread of a warming planet, so much so that to be worried about the later, at the expense of the former, seems to be intellectual laziness 'par excellence'Both are serious problems. Both could destroy not only civilisation, but - at the extreme end of the spectrums - all life on Earth. Trying to compare the two, which are so different in character, is an exercise in futility, an unwelcome distraction, and might even be characterised as intellectual presumptuousness par excellence. Let's just agree it is a serious issue and move on.
But it makes sense, just as mass extinctions in the past, have almost all been the result of celestial Impactors as well.No they haven't. You have been watching the Discovery channel too much rather than reading the literature. OK, thats a cheap shot, but really, consider the data.

Holocene Event ........ That one is down to us.
KT Boundary ............ An impactor is strongly implicated, but its central role as the primary cause is still disputed.
Triassic/Jurassic....... No impactor.
End Permian........... Cause unknown, but probably related to land distribution and possibly H2S release. No impactor.
Late Devonian....... No Impact evidence.
Ordovician....... No impact evidence.

Only one of the six major extinction event is closely tied to an impactor.
The thing that leaves me scratching my head is the frequency with which commentators, and even scientists use "asteroids" and "comets" so interchangably. Please cite a single instance in which a scientist has used the terms interchangeably. Note that for some impacts we do not know which was responsible, comet or asteroid. For these situations the general term bolide is preferred.
Also, comets are almost always much bigger than asteroids. I agree this is true by a couple of orders of magnitude, but there are still some big asteroids out there, fortunately in stable orbits. A hit by Ceres would be embarassing.

But I am fairly certain that an Impactor is the reason for the mass extinction of certain fauna in North America . As a matter of fact, it is starting to look like ALL mass extinctions are the result of celestial intervention.
You seem to be confusing fashion with facts, the opinions of scientists with the findings of science.
This is why I am amazed with the Eco-Wackos's hysteria about something as benign as global warming, I'm sorry, I should have read the whole thread before I started my reply. I didn't realise you had an agenda.

Triassic/Jurassic....... No impactor.


For real? Gulf of Mexico crater debunked?

The Chicxulub crater in the Gulf of Mexico is the KT(Cretaceous-Tertiary) boundary event. The crater is very real, it undoubtedly led to extensive extinction, but whether it was the primary cause remains the subject of debate.

As a graduate student I have always believed that there had to be something other than invading humans responsible, because the diversity of extinctions and their suddenness just did not add up.Why do you say that? The settling of the Western Hemisphere was a unique event in human history.

Humans originally evolved in Africa. All of the advances in our hunting technology occurred with agonizing slowness, and the prey species had plenty of time to react to them and evolve new instincts and behaviors.

Humans migrated to Asia fifty or sixty thousand years ago, when we were still limited to Paleolithic technology: even clothing was a recent invention. We fanned out very slowly across the new continents, and once again the animals had a chance to adapt their behavior to the risk our presence posed.

Even Europe: 25,000 years ago. Still the Paleolithic. Neanderthals were already there, but given that we quickly outcompeted them to extinction, they presumably did not have high technology. Homo sapiens spread very slowly across Europe, following the receding glaciers. We can be classified as simply one component in the changing ecosystem. The only animals who were able to make the migration with us and define the new post-glacial ecosystem were the ones who were able to survive in a hostile environment full of hungry humans with spears and clever hunting strategies.

Humans came to the Americas only 13,000 years ago, with more sophisticated technology than their ancestors had, including the complex language that was one of their most effective tools for organization. Didn't humans spread rapidly, covering the entire New World in less than a millennium? Those animals didn't know what hit them.

No, Humans were present in America a lot earlier. Mitochondrial DNA research suggests about 30,000 years. I'll link later

But the most compelling evidence literally is a piece of s***

http://www.sciencemag.org/cgi/content/abstract/sci;320/5877/786

We establish that humans were present at Paisley 5 Mile Point Caves, in south-central Oregon, by 12,300 14C years B.P., through the recovery of human mitochondrial DNA (mtDNA) from coprolites, directly dated by accelerator mass spectrometry. The mtDNA corresponds to Native American founding haplogroups A2 and B2. The dates of the coprolites are >1000 14C years earlier than currently accepted dates for the Clovis complex.

Note that carbon dates need calibration using the INTCAL04 table (http://www.radiocarbon.org/IntCal04.htm)

12,300 radiocarbon years ago is about 14,150 Calendar years ago.

No, Humans were present in America a lot earlier. Mitochondrial DNA research suggests about 30,000 years. I'll link later

But the most compelling evidence literally is a piece of s***

http://www.sciencemag.org/cgi/content/abstract/sci;320/5877/786



Note that carbon dates need calibration using the INTCAL04 table (http://www.radiocarbon.org/IntCal04.htm)

12,300 radiocarbon years ago is about 14,150 Calendar years ago.

And that's with searching the high country. During the ice-age, the sea shore areas where people would have inhabited the most were some 100 meters lower, and are now flooded, making their s--- undetectable! So when does underwater archaeology begin exploring those old sea-shore areas?

Humans came to the Americas only 13,000 years ago,

False. New finds have humans coming much earlier than that.

I'm sorry, I should have read the whole thread before I started my reply. I didn't realise you had an agenda.

No real surprise there; the forum he linked to is a notorious right wing haven. The biggest asshole I've ever encountered on line used to frequently post there.

False. New finds have humans coming much earlier than that.We've got this same discussion going on in another thread. Of course there have always been adventurers, and there's clear evidence that bands of humans managed to explore the New World long before the Paleoindians settled here. But there's no convincing evidence that they established communities that survived and contributed in any meaningful way to either the DNA or the culture of the people we regard as the aboriginal Americans. People came, traveled around, lived off the land, and some of them may have managed to have children who grew up and had children of their own. But at some point the colonies failed and died off. The new generation of research technology has facilitated an enormous amount of DNA analysis in just the last couple of years. The rather ample population samples of New World ethnic groups tested consistently show that they are descended from a couple of waves of migrants whose relatives stayed behind in Siberia, and they've even located the descendants of those relatives who are still in Siberia. Links to the material were posted in the "Out of Africa" thread some months back.

I guess we'll see what studying the new Mexican skeletons brings to light.

We've got this same discussion going on in another thread. Of course there have always been adventurers, and there's clear evidence that bands of humans managed to explore the New World long before the Paleoindians settled here. But there's no convincing evidence that they established communities that survived and contributed in any meaningful way to either the DNA or the culture of the people we regard as the aboriginal Americans. People came, traveled around, lived off the land, and some of them may have managed to have children who grew up and had children of their own. But at some point the colonies failed and died off. The new generation of research technology has facilitated an enormous amount of DNA analysis in just the last couple of years. The rather ample population samples of New World ethnic groups tested consistently show that they are descended from a couple of waves of migrants whose relatives stayed behind in Siberia, and they've even located the descendants of those relatives who are still in Siberia. Links to the material were posted in the "Out of Africa" thread some months back.

You may be unaware of the considerable evidence and study on the settlement of NA that disproves the 'land bridge', and the history of a Clovis point technology from Europe. Via the Solutreans. Bear in mind this is not the work of some crackpots looking to garner attention, but of a Smithsonian Archaeologist Dennis Stanford and colleague Bruce Bradley in 2002. The dig at Cactus Hill alone certainly opens some questions up some valid questions.

There are question about is, and those that criticize the work. But there are always many critics of new theories, for many reasons including simple human ego.

The classical 'land bridge' approach, north to south, west to east, while being tried and true as far as academia goes,(which means if you actually want to get published and move ahead in academia you better stay with the program), is full of holes and research done in the last five years continues to poke more holes in it.

From the digs and dating in western Mexico and South America. To the new examination of the European source of Clovis technology.

You may be unaware of the considerable evidence and study on the settlement of NA that disproves the 'land bridge', and the history of a Clovis point technology from Europe.So why don't you fix that and post a URL. Better yet, use the book report skills they forced us all to learn in grade school and post a brief abstract for us.Via the Solutreans.I read the Wikipedia article and it appears to be good science and in accordance with the Rule of Laplace we are obliged to treat it with respect. But this short writeup leaves it with a lot of very difficult unanswered questions.There are questions about it, and those that criticize the work. But there are always many critics of new theories, for many reasons including simple human ego.The reason most new theories are criticized is that they violate the Rule of Laplace: Extraordinary assertions must be accompanied by extraordinary evidence before we are obliged to treat them with respect. This is what identifies the crackpot: He does not see his hypothesis as extraordinary because he has been living with it for so long and it may even be consuming him and defining his life.The classical 'land bridge' approach, north to south, west to east, while being tried and true as far as academia goes,(which means if you actually want to get published and move ahead in academia you better stay with the program), is full of holes and research done in the last five years continues to poke more holes in it.The "water bridge" hypothesis has been proposed and it works just as well. The people in many Mesolithic East Asian societies were amazingly skillful sailors, and working in their favor was the phenomenon of shorter distances to navigate in an ice age due to lower sea levels and wider land masses. The Paleoindians could just as easily have sailed over.From the digs and dating in western Mexico and South America. To the new examination of the European source of Clovis technology.I found the remarks on DNA most interesting. The relationship between the indigenous Americans and the modern remnants of a Siberian tribe is too close to gainsay. But perhaps there was a substratum of European DNA and culture that has left its telltales in both the biological and archeological record.

This is why I am amazed with the Eco-Wackos's hysteria about something as benign as global warming, and totally oblivious to the REAL DANGER, which lies out in the Ort Cloud and Kuiper Belt. All it takes is for one of these Impactors to give us a personal visit, and we are Truely Screwed, Blued, and tatooed.

Benign as global warming??? WTF? It's an issue we are in control of, more or less, political issues notwithstanding.

Further, what exactly do you propose we do about the "impactor" issue? Bruce Willis is already booked.:rolleyes:

Tho I do have to say, some interesting ideas here, thread wise.

Benign as global warming??? WTF? It's an issue we are in control of, more or less, political issues notwithstanding.

No; you see, worse cataclysms have happened in the past, so we shouldn't worry about a relatively minor cataclysm in the present time. And you have to get your climate change deniers classified correctly - there are still a minority that deny that global temperatures are changing at all, then there are the ones that concede that they are, but still refute that it has been caused by humans. One thing I have yet to comprehend is the way they seem so happy at the idea that global climate change isn't caused by human activity. If it isn't caused by human activity, then there really is nothing to be done, and we are truly helpless in the face of negative consequences (for humans) that will follow a relatively minor change in global temperatures. This is good news?

No; you see, worse cataclysms have happened in the past, so we shouldn't worry about a relatively minor cataclysm in the present time. And you have to get your climate change deniers classified correctly - there are still a minority that deny that global temperatures are changing at all, then there are the ones that concede that they are, but still refute that it has been caused by humans. One thing I have yet to comprehend is the way they seem so happy at the idea that global climate change isn't caused by human activity. If it isn't caused by human activity, then there really is nothing to be done, and we are truly helpless in the face of negative consequences (for humans) that will follow a relatively minor change in global temperatures. This is good news?

That so much clearerer.:rolleyes:

One thing I have yet to comprehend is the way they seem so happy at the idea that global climate change isn't caused by human activity.Yes. I have always said that scientists should stop emphasizing the human connection, even if it's true, and focus mankind's attention on the effects of global warming rather than the cause. Our descendants won't really care whether global warming was our fault as long as we fixed it. And if we don't fix it and it's really as bad as the models predict, the few who survive will probably be so primitive that they won't retain any knowledge of our history.If it isn't caused by human activity, then there really is nothing to be done. . . .Why do you say that? Most of the endeavors that have been recommended for slowing or reversing global warming are good science, regardless of whether it was caused by our carbon footprint, cow farts, sunspots or the randomness of Mother Nature. Even if there's an underlying cause we haven't yet discovered that has nothing to do with us, continuing to belch carbon will make it worse and not continuing to belch carbon will make it better. The question is whether we can make it enough better to solve the problem, and the majority of respectable scientists seem to think so... as long as Mother Nature doesn't decide to pick up the tempo.. . . . and we are truly helpless in the face of negative consequences (for humans) that will follow a relatively minor change in global temperatures. This is good news?I don't think that's a logical conclusion to derive from the facts that we have gathered so far, so it's not news at all. The models of the climate don't include "how it got this way" as an important variable.

Yes. I have always said that scientists should stop emphasizing the human connection, even if it's true, and focus mankind's attention on the effects of global warming rather than the cause. Our descendants won't really care whether global warming was our fault as long as we fixed it. And if we don't fix it and it's really as bad as the models predict, the few who survive will probably be so primitive that they won't retain any knowledge of our history.Why do you say that? Most of the endeavors that have been recommended for slowing or reversing global warming are good science, regardless of whether it was caused by our carbon footprint, cow farts, sunspots or the randomness of Mother Nature. Even if there's an underlying cause we haven't yet discovered that has nothing to do with us, continuing to belch carbon will make it worse and not continuing to belch carbon will make it better. The question is whether we can make it enough better to solve the problem, and the majority of respectable scientists seem to think so... as long as Mother Nature doesn't decide to pick up the tempo.I don't think that's a logical conclusion to derive from the facts that we have gathered so far, so it's not news at all. The models of the climate don't include "how it got this way" as an important variable.

Oh, come on F.R. He wasn't supporting those positions. He was expressing their inexplicability. That's what I understood him to be saying, anyway

To clarify my position, I think it is good news if climate change is caused by human activity, and bad news if it is not. I think it is more likely that we will take effective action in a timely manner if we are the cause. We possess the capability to undo changes we have caused, though we may choose not to out of apathy or selfishness and greed. If there are still unknown elements at work fueling climate change, we may not be able to stop it, even if we stop stoking the fires with our carbon dumping. The position that "We aren't causing it, therefore we don't even need to try and do anything about it, and it probably isn't really happening anyway" mostly confuses me as to how it is supposed to be good news.

This position does seem to be most popular with the sort of people who believe that all of the animals on Earth were saved from a global flood by a big boat. If you can believe that sort of thing, I guess you can believe anything.

Thank you for the clarification. I do agree your earlier posts left me a little uncertain of what you were saying.
I would agree with your assessment and may even - with your permission - quote it on other fora as a reflection of what I think on the matter.

Thank you for the clarification. I do agree your earlier posts left me a little uncertain of what you were saying.
I would agree with your assessment and may even - with your permission - quote it on other fora as a reflection of what I think on the matter.

You flatter me. Of course you have my permission.

Yes. I have always said that scientists should stop emphasizing the human connection, even if it's true, and focus mankind's attention on the effects of global warming rather than the cause. The idea that global warming is not human influenced seems wedded to the notion that the current warming is part of a natural cycle,

and the notion that it is part of a natural cycle seems to me to lead to the conclusion that we can't do anything about it, so we shouldn't spend money trying.

And the reason that is goods news is that its proponents don't want to spend any money trying, or rearrange their lives in troublesome ways on such abstract grounds. They have enough problems, and not enough money, already.

The problem with handling the effects alone, rather than the cause(s), is that the effects will be overwhelmingly greater if the major cause turns out to be human and has not been handled.

To clarify my position, I think it is good news if climate change is caused by human activity, and bad news if it is not.

Exactly right, exactly and what is the result of that strong desire?

Highly recommend to read this:

http://jan.ucc.nau.edu/~dmo2/Chesser%20Baker%2006%20Chernobyl.pdf

Lesson 1: Beautiful theories are often destroyed by ugly facts.
Lesson 5: Scientists must have a single agenda: the truth.
Ronald K. Chesser and Robert J. Baker, 2006, Growing Up with Chernobyl,
American Scientist, Volume 94 pp 524-529

Science is not wishful thinking.

Another evergreen quote with the same idea:

http://muller.lbl.gov/TRessays/23-Medievalglobalwarming.html

.... I would love to believe that the results of Mann et al. are correct, and that the last few years have been the warmest in a millennium.

Love to believe? My own words make me shudder. They trigger my scientist's instinct for caution. When a conclusion is attractive, I am tempted to lower my standards, to do shoddy work. But that is not the way to truth. When the conclusions are attractive, we must be extra cautious.

The AGW swindle that looks vaguely like science will backfire so incredibly hard when the truth overtakes it.

Andre, I would be very happy if climate change turned out to be completely wrong. Don't confuse me with someone who takes satisfaction in the idea that industrial civilization is dooming itself. I'd also be very happy if crude oil turned out to be abiotic in origin, and would never run out. I love driving powerful automobiles and motorcycles, and using air conditioning, refrigeration, and home heating. If we could live and consume just as we are right now indefinitely into the future, that would be great news.

I think the standard of living we take for granted in the west is great, and I'd like for it to become the standard of the world. I'm not going to let my desires for the future to be much the same as the present to cloud my judgment. Truth may not be arrived at by consensus, but when the overwhelming majority of scientists qualified in their fields say we should be worried, and that we should take action, it seems prudent to me to listen to them. The alternative seems to be that these scientists are conspiring to fool people for reasons that are not at all clear. Not being a fan of conspiracy theories, this seems incredibly unlikely to me.

Truth may not be arrived at by consensus, but when the overwhelming majority of scientists qualified in their fields say we should be worried, and that we should take action, it seems prudent to me to listen to them. The alternative seems to be that these scientists are conspiring to fool people for reasons that are not at all clear. Not being a fan of conspiracy theories, this seems incredibly unlikely to me.Um, it seems to me that you overlooked a simpler explanation: They're all wrong.

There are two forces buffeting science these days. One is pure hubris. Many scientists think they've got it all figured out. When it comes to the climate that just has to be a big damn joke: we don't know jack shit about it. In my own lifetime those same scientists were screaming at us about the threat of global cooling.

The other is corporate pressure. In the waning years of the Industrial Era, corporations have become forces of evil, and a good many scientists are employed by corporations. (Or by governments, which are just as bad if not worse.) They trade their integrity for a paycheck and spend their careers trying to prove their hypotheses instead of trying to disprove them, a fundamental violation of the scientific method.

Um, it seems to me that you overlooked a simpler explanation: They're all wrong.

Always possible, but it certainly doesn't seem likely to me.

There are two forces buffeting science these days. One is pure hubris. Many scientists think they've got it all figured out. When it comes to the climate that just has to be a big damn joke: we don't know jack shit about it. In my own lifetime those same scientists were screaming at us about the threat of global cooling.

This has been covered extensively, probably best by Real Climate. (http://www.realclimate.org/index.php?p=94) There were no scientists screaming, but the popular press was another thing (I remember being frightened by it as a child). It really isn't comparable to the massive consensus in the scientific community at this time.

In my experience, education is always humbling; I jokingly refer to it as expanding the horizons of my ignorance. I would think that no one knows better just how much there is still to learned about the complexity of the Earth's climate than climate scientists. But what they are observing with the understanding of it that they have at this time seems to alarm most of them. As Isaac Asimov said, "The purpose of crying doom is to avert it."

The other is corporate pressure. In the waning years of the Industrial Era, corporations have become forces of evil, and a good many scientists are employed by corporations. (Or by governments, which are just as bad if not worse.) They trade their integrity for a paycheck and spend their careers trying to prove their hypotheses instead of trying to disprove them, a fundamental violation of the scientific method.

Astro turf science has been a very real phenomena in the past few years. If they can refute specific claims, then they do a service by making the science more accurate. But they seem to mostly serve to muddy the waters, and seem to be most successful at making laymen think there is a controversy when there actually isn't one.

When it comes to the climate that just has to be a big damn joke: we don't know jack shit about it. In my own lifetime those same scientists were screaming at us about the threat of global cooling.Here is some news for you FR: assuming we manage to avoid catastrophic, run away green house, then our next big challenge in the next couple of millenia is global cooling and the return of the ice.
That has not changed at all in the last four decades. What has changed is our time focus. When the next ice age was around the corner, in geologic terms, no one had yet noticed that something was happening to global temperatures on a much more human scale.

I think the standard of living we take for granted in the west is great, and I'd like for it to become the standard of the world. I'm not going to let my desires for the future to be much the same as the present to cloud my judgment. Truth may not be arrived at by consensus, but when the overwhelming majority of scientists qualified in their fields say we should be worried, and that we should take action, it seems prudent to me to listen to them. The alternative seems to be that these scientists are conspiring to fool people for reasons that are not at all clear. Not being a fan of conspiracy theories, this seems incredibly unlikely to me.

There is no overwhelming majority

http://mclean.ch/climate/IPCC.htm


and here are the not-at-all-clear reasons:

Copying from a mail:

I believe that there have been three major politically driven scaremongering offences.

The first one in the 80s which has been analyzed razorsharp by Richard Courtney, Margareth Tatcher wanted to get away from coal in favor of nuclear energy.

Details here: http://www.john-daly.com/history.htm

The second main trust, came from Enron in the 90s. It had made fortunes out of trading sulphur emission permits in the cap and trade system and had dollar signs in the eyes when thinking of cap and trading CO2 permits.

Details here: http://www.investigatemagazine.com/archives/2006/03/investigate_oct_5.html

The third offence obviously came from Al Gore and the incovenient truth. At the time I thought it was according the observation of H.L. Mencken: The urge to save humanity is almost always only a false-face for the urge to rule it. But Gore did not go for the highest function. This puzzled me a bit but it was shown that he merely inherited the dream of Enron, cap trade and get incredibly rich:

http://www.larouchepub.com/other/2007/3413carbon_swindle.html

Problem is that he will get his way, regardless who wins the White House. See both answers to question 2:

http://www.sciencedebate2008.com/www/index.php?id=40
http://www.sciencedebate2008.com/www/index.php?id=44

It's probably getting a lot worse.