No problem, here is an interesting paper on proposed causes, the conclusion being it wasn’t one event alone but a synergistic combination of events, this seems a reasonable assumption. http://www.pnas.org/content/99/7/4172.full.pdf+html

As regards evidence of global warming caused by the atmospheric changes discussed in the article, the following offer good paleantological evidence:

Wignall, P. B., Morante, R. & Newton, R. 1998 The Permo{Triassic transition in Spitsbergen:
delta 13Corg chemostratigraphy, Fe and S geochemistry, facies, fauna and trace fossils. Geol.
Mag. 135, 47{62.
This illustrates the migration of warm water algae to higher latitudes;

The following references show a change from cool peat formation to warm temperate soils and plants
Retallack, G. J. 1996 Paleoenvironmental change across the Permian{Triassic boundary on land
in southeastern Australia and Antarctica. In Proc. Int. Geol. Congr. Beijing (abstract volume),
p. 109.

Retallack, G. J. 1995 Permian{Triassic life crisis on land. Science 267, 77{80.

Dee Norris (22:44:47)
“….eliminated 9 out of 10 locals with infectious diseases like small pox. The decimation took place ….”

As decimate is now used for any large scale eradication/loss it’s interesting to note that, used correctly, decimate means a 1 in 10 loss. The word comes from the Romans who would punish a legion by picking by lots of one soldier in ten to be executed. “Marvelous race the Romans..”

The P/T extinction (~245 million years ago) occured at about the same time as the creation of the Siberian traps (huge volcanic deposits) which reduced the oxygen content of the atmosphere to as low as 9% over a period of several million years.

We are not talking H. erectus who vanished off the face of the Earth about 70 thousand years ago, but it’s very smarter cousin, the tooling using hunter known as H. sapiens whose ’survive at all costs’ genetic heritage is from the survivors of the Toba explosion.

The North American mega-fauna had survived prior ice ages and interglacials without mass extinctions until the arrival of the Clovis culture about 13 thousand years ago and vanished about 200 to 800 years later. Shortly after their arrival, there is a large comet/asteroid impact and lots mass extinctions. In other parts of the world, where every H. sapiens shows up, the mega fauna goes extinct, no impact needed. Coincidence? I think not.

We lack the data to determine if the Native Americans (who arrived with most recent waves of wanderers across the Bering land bridge) would have eventually exterminated the bison had not Europeans arrived and eliminated 9 out of 10 locals with infectious diseases like small pox. The decimation took place a couple hundred years before the opening of the American West and the near extinction of the Bison. That 200+ years is more than enough time for the bison herds to re-fill the ranges.

@tty and Mary Hinge:

“I agree with almost all your points, especially the out of Africa and the lack of fear of the Homo genius everywhere but Africa.”

With due respect this is just plain silly. Homo erectus evolved along side the fauna and flora. We are a product of the environment. I doubt very much that early Mankinds history will show a sudden desire to munch on large wild animals unless it was a survival imperative. Even armed with fire and spear it was a dodgy prospect.

Man was on the scene with teaming bison on the north American continent. It took the gun to blow them close to extinction, not bows and arrows or spears and fire. It’s probable that the abrupt swings between ice ages and warm periods put extreme strains on beasts that can’t quickly adapt.

The second “Important Lesson” is that this amateur only discovered it 24 hours before impact. So not much room for Hollywood to make Bruce-Willis-saving-the-Earth films there.

There is no coordinated search for boulder-sized objects. There is a search going on to find and catalog all asteroids with a size greater than 1 Km in Earth orbit crossing orbits.

Several asteroids have been found only when they’ve been _leaving_ our vicinity, that’s one of the reasons for pushing this program. A few have gone by inside the Moon’s orbit around Earth.

The third important lesson is the diameter of the meteorite, at 3/4/5/6 metres (nobody seems sure).
Are these sizes fixed by God, on a sort of quantum basis, or can one, on a direct trajectory, of enormous size, and therefore weight (4/3 x Pi x R^3), get through, over a populated area of the globe, before the “Spaceguard” screen can spot it and so alert Hollywood that another meteorite blockbuster film is imminent? Post mortem.

There is a relationship between size and number. The smaller the size, the more there are.

Don’t rely on Hollywood scripts for stopping asteroids. The goal is to find something that will impact in the next decade or so, then send a probe to the asteroid in a trip lasting months, and start an ion engine that provides an efficient thrust to change the orbit ever-so-slightly so that it misses Earth (and probably take a slinshot trajectory into a safer orbit). In real life rocket science, nothing happens quickly except leaving the atmosphere. It takes many orbits for the space shuttle to rendevous with the ISS.

If you think these lessons are important, then you should take the time to learn more about the project. You might also complain to the major news media that they should spend less time on the US presidential election and more time on material not covered every day for the last year. I was visiting a meteorologist at a Boston TV station once while he did his 11PM segment and he alerted viewers that there might be an aurora that night. The news director called after the news ended to chew him out for talking about something of interest so few people besides his amateur astronomer friends.

In researching this reply, these sites are good starting points:

http://geology.com/articles/earth-crossing-asteroids.shtml
http://impact.arc.nasa.gov/intro_faq.cfm
http://www.sanfranciscosentinel.com/?p=6798
http://neo.jpl.nasa.gov/news/news157.html
http://geology.com/news/2008/asteroid-2007-tu24-close-flyby-of-earth-on-january-29.shtml
http://neo.jpl.nasa.gov/news/news151.html
http://www.ll.mit.edu/mission/space/linear/
http://www-b.jpl.nasa.gov/releases/98/neatasts.html

There’s a nice 600-million-year composite plot of temperature and carbon dioxide here (scroll down):

http://www.geocraft.com/WVFossils/Carboniferous_climate.html

It shows temp and CO2 comparable to current conditions for most of the Permian, with both rising toward the end. Check the sources given for the plot to see methodologies and reconstructions, especially the continental configurations.

I can’t vouch for the sources, since proxy reconstructions in general remind me of black magic (*cough*Mann*cough*), especially ones going back hundreds of millions of years. Even if the results are reasonably accurate, the relevance to our current climate system is unclear, given the radically different continental layout.

I agree with almost all your points, especially the out of Africa and the lack of fear of the Homo genius everywhere but Africa.

However, none of the other large Late Pleistocene extinctions have an asteriod impact in the general chronological vicinity. More than likely both humans and the impact drove the North American mega-fauna extinction. The Clovis culture may have very well started and finished the job with the impact sandwiched in between.

Does this go against your belief that the amount of CO2 in the atmosphere has no effect on global temperatures?

You might find this absolutely surprising but I do believe that CO2 has a large impact on temperature, but just not at the current concentrations.

Can you cite a more reliable source than geocities for PT warming? Thanks.

One continent in particular supports the theory of human caused extinction, Africa. This continent has large populations of large mammals and is also the birthplace of man. The mammals evolved with man and modified their behaviour accordingly. As man spread to different continents the larger mammals hadn’t evolved the fear factor and were relatively easy prey.
The Pleistocene asteroid could certainly have contributed to the extinction of many species though, larger mammals would be susceptible to population fragmentation and with a long reproduction cycle would be canditates for extinction. In North America it was probably a combination of the two with the asteroid speeding up the process.

Reply – Spaceguard is mostly amateurs and that we could track something that small to the end is a first. I stand by my words. Can you imagine how much better spotting and tracking would be if just a small part of the funding targeted to stop AGW were shifted to a professional Spaceguard project? – Dee Norris

You are absolutely right!
Especially since the Late Pleistocene extinction of megafauna was not limited to North America, and the timing coincides very well with when Homo sapiens arrived in each area.
It seems a bit contrived to postulate a string of asteroids hitting each continent in turn just as the first humans are settling in.

“By the beginning of the Permian, the motion of the Earth’s crustal plates had brought much of the total land together, fused in a supercontinent known as Pangea.”

Plate tectonics has established that supercontinents are a recurrent form, and have been associated with global temps of upto 72 degrees vis a vis the current 56 degrees sans supercontinent. The issue is ocean currents, not CO2.

CO2, at STP, has an emissivity of 9*10^10-4 versus 0.94 for green leaves. Even the Rainman cannot argue one that away. The earth’s terrestrial surface radiates heat 1000 times more effectively than CO2.

Because the paleaontological evidence shows there was warming! A good start on this subject is here http://www.geocities.com/earthhistory/permo.htm

I wonder why you seem to be so reluctant to accept that changes in atmospheric constituents can cause global warming as well as global cooling. Does this go against your belief that the amount of CO2 in the atmosphere has no effect on global temperatures?

It seems that giving to Nobel Peace Price to the IPCC has suddenly increased the number of “Nobel Prize Winning scientists” by about an order of magnitude. I suppose that Steve MacIntyre can call himself a “Nobel Prize Winner” too, since he was a IPCC reviewer. In fact I almost wish he would, since all righteous MSM (including Reuter) would then undoubtedly discover the speciousness and arrogance of such claims.

Climate scientist is thrilled by the economic mess. We may freeze and starve to death, but at least our CO2 is reduced.