Are we in the midst of the sixth mass extinction?

[Nereid]

Bystander wrote: *SNIP
The only historical information I can see/agree to at the moment is that we can calculate/estimate an average difference in appearance and extinction rates
*SNAP

How?

 

[Bystander]

Originally posted by Nereid
(snip)The difference between the rate of appearance of species and the rate of extinction of species is then obtained by simple algebra from the above.(snip)

"How?"

You followed it once, seemed to get along with the idea, and now you ask, "How?"

 

[Nereid]

Originally posted by Bystander
"How?"

You followed it once, seemed to get along with the idea, and now you ask, "How?"

Just want to be sure

In terms of my original proposal:
1) We all agree on what constitutes a mass extinction.

2) Bystander and Russ propose a definition of the 'normal' or 'background' extinction rate; we discuss it and agree.

3) We agree on what the actual background extinction rate has been, up to 1mya.

4) I propose a means of estimating the present extinction rate; we discuss it and agree.

5) I will make an estimate of the present extinction rate; we discuss it.

Supplementary topic: if we agree that number six is in progress, then we look for causes.

We agreed (more or less) on 1).

Bystander decided that 2) was impossible to work with, in any practical sense (and Russ is playing truant).

Which means the end of this little experiment (unless someone would like to suggest how we could continue).

It's been pretty quiet; since 29 Feb, only Nereid and Bystander - have we bored everyone to tears?

 

[Bystander]

Mass extinction of the audience --- no sound but the crickets. Actually been fun --- learned a couple things.

There may be something hiding in the power law distribution material, but that's going to be a while.

Later --- B.

 

[meteor]

The World's No.1 Science & Technology News Service



Earth faces sixth mass extinction


19:00 18 March 04

NewScientist.com news service

The Earth may be on the brink of a sixth mass extinction on a par with the five others that have punctuated its history, suggests the strongest evidence yet.

Butterflies in Britain are going extinct at an even greater rate than birds, according to the most comprehensive study ever of butterflies, birds, and plants.

There is growing concern over the rate at which species of plants and animals are disappearing around the world. But until now the evidence for such extinctions has mainly come from studies of birds. "The doubters could always turn around and say that there's something peculiar about birds that makes them susceptible to the impact of man on the environment," says Jeremy Greenwood of the British Trust for Ornithology in Norfolk, and one of the research team.

http://www.newscientist.com/news/news.jsp?id=ns99994797

 

[Bystander]

Meteor-

Nereid thanks you, and I thank you --- the silence in this thread has been deafening. This is another version of what started this thread ---- sort of "deja vu all over again." We got stalled by my refusal to consider extinction rates alone as sufficient cause for concern, coupled with the fact that "appearances" are difficult to observe.

"--- populations of 71 percent of the butterfly species have decreased over the last 20 years, compared to 56 percent for birds and 28 percent for plants. Two butterfly species (3.4 percent of total) became extinct, compared to six (0.4 percent) of the plant species ----" This isn't too horribly out of line with first order rate estimates based on Lake Victoria cichlids (appearance and extinction rates in my analysis) --- 3x10^-4/a taken over a twenty year interval is 0.6%; compared to observed rates of 3.4, 0.4, and 0.0 for three species groups, I'd have to say, "No surprises here." Nereid may have other conclusions and comments.

The population studies likewise have to be examined in a broader context --- is the island turning a dead brown, or are populations of other species increasing? Population biology is a completely different problem and, excepting the cases where populations crash to zero, unrelated to the extinction problem.

 

[Andre]

OK, some feedback on this old thread based on the alarming hype about extinction that triggered this thread (alliterations allowed?) into existence.

I may have remarked that this was the worst sciencific paper I have ever seen, the model was based almost solely on extrapolating some extinctions of the last few decades that were not caused by changing climate at all. Furthermore, of the some 33 identified major (climate(?) upheavals in the last million years there is only one that is associated with some explicit extinctions (the Pleistocene steppe megafauna Mammoths) around 11,570 years ago.

Well. Here is the retreat .

Charities 'spread scare stories on climate change to boost public donations'
By Elizabeth Day
(Filed: 02/05/2004)

Environmental charities are exaggerating the threat of climate change in an attempt to raise more money from public donations, according to a report by Oxford University academics...

 

[Bystander]

Eeehhhhhhhhh ---- hmmmm. Sloppy science begets sloppy journalism begets sloppy public interest group activities begets sloppy political activism begets sloppy funding of sloppy science? Naaahhh --- people are opportunists --- Svante Arrhenius speculated about "global warming" a century ago, and people have been hunting ways to connect their names with his since then. That, plus the "publish or perish peer review process" has placed a number of speculations into the public record that would have been "edited" to the circular file by the pre-WWII scientific establishment --- violations of first principles and basics of technique, and just plain WRONG science did not get published in them days. Today, 10k journals competing for space on shelves waste a lot of paper and ink publishing "peer-reviewed" pure bunkum --- post WWII/Cold War peer-review is more a matter of "don't trash me and I won't trash you 'cause we're both in the same publish or perish boat."

 

[Andre]

Just for the record another casual opinion on that paper:

http://www.washtimes.com/commentary/20040114-083322-9283r.htm

Massive extinction of logic
By Patrick J. Michaels

Much has been made of a paper published on Jan. 8 in the journal Nature by Chris Thomas and 18 co-authors, claiming global warming will cause a massive extinction of the Earth's biota. Mr. Thomas told The Washington Post: "We're talking about 1.25 million species. It's a massive number."
It turns out that there is a massive number of glaring problems with their study that clearly eluded the peer review process. This is evinced by the rapid turnaround for the manuscript, with acceptance in final form a mere five weeks after original submission. No one can clear revisions through 19 authors in that time unless there weren't many revisions suggested, or, if there were, they were ignored by the journal's editors in a rush to publication.

In fact, acrimonious debates about what should or should not be published about global warming are the rule rather than the exception, simply because papers are being published — on many sides of the issue — that can be shredded after only a cursory review. Unfortunately, the debate may have started with Nature itself.

In 1996, conveniently a day before the U.N. conference that gave birth to the Kyoto Protocol, Nature published a paper purporting to match observed temperature with computer models of disastrous warming. It used weather balloon data from 1963 through 1987. The actual record, however, extended (then) from 1958 through 1995, and, when all the data were used, the troubling numbers disappeared. Since that famous incident, people have been very leery of what major scientific journals publish on global warming. The Thomas extinction paper only throws more fuel on an already roaring inferno.

The work of Mr. Thomas et al. is an interesting exercise in computer modeling showing again that what comes out of a computer is a product of the assumptions that go in. The scientists examined the distribution of more than 1,000 plants and animal species, calculated their current climatic range, and then used a climate model to determine whether the amount of land the species could occupy in the future would shrink or expand. If there was a likely shrinkage, the researchers expected an increased chance of extinction.

etc, etc

Patrick J. Michaels is senior fellow in environmental studies at the Cato Institute.