Climate risk 'to million species'

[Nereid]

I've just started a new thread in Biology*, 'Are we in the midst of the sixth mass extinction?'

Let's have some stimulating intellectual discussion!

*https://www.physicsforums.com/showthread.php?s=&postid=130402#post130402

 

[Tsu]

Originally posted by Nereid
I've just started a new thread in Biology*, 'Are we in the midst of the sixth mass extinction?'

Let's have some stimulating intellectual discussion!

*https://www.physicsforums.com/showthread.php?s=&postid=130402#post130402

Ivan says "Nah. Let's just beat up on russ."

 

[russ_watters]

Originally posted by Tsunami
Ivan says "Nah. Let's just beat up on russ."

Well, I could use a good beating...

 

[Tsu]

Originally posted by russ_watters
Well, I could use a good beating...

 

[Andre]

I like to comment on the original topic:

Climate change could drive a million of the world's species to extinction as soon as 2050, a scientific study says.
The authors say in the journal Nature a study of six world regions suggested a quarter of animals and plants living on the land could be forced into oblivion.

They say cutting greenhouse gases and storing the main one, carbon dioxide, could save many species from vanishing.

The United Nations says the prospect is also a threat to the billions of people who rely on Nature for their survival.

http://news.bbc.co.uk/2/hi/science/nature/3375447.stm

So what did they do?

Exploring three approaches in which the estimated probability of extinction shows a power-law relationship with geographical range size, we predict, on the basis of mid-range climate-warming scenarios for 2050, that 15–37% of species in our sample of regions and taxa will be 'committed to extinction'. When the average of the three methods and two dispersal scenarios is taken, minimal climate-warming scenarios produce lower projections of species committed to extinction (18%) than mid-range (24%) and maximum-change (35%) scenarios. These estimates show the importance of rapid implementation of technologies to decrease greenhouse gas emissions and strategies for carbon sequestration.

Which three methods?

We explore three methods to estimate extinction, based on the species–area relationship, which is a well-established empirical power-law relationship describing how the number of species relates to area ...
In method 1 we use changes in the summed distribution areas of all species...
in method 2 we use the average proportional loss of the distribution area of each species to estimate the fraction of species predicted to become extinct.
Thus, in method 3 we estimate the extinction risk of each species separately by substituting its area loss in the species–area relationship, before averaging across species

Source:
Nature 427, 145 - 148 (08 January 2004); doi:10.1038/nature02121

Extinction risk from climate change, Thomas et al.

That's it. So not why method 4? and test your hypothesis and check how many species became extinct with earlier violent climate changes in the recent past.

The Pleistocene Holocene boundary: bingo: about 10-20 degrees assumed temperature change and we have a massive extinction of megafauna, Mammoths Mastodonts, giant ground sloth, etc. Many google hits on those keywords. Good start.

So Hypothesis proven?
How about the Dansgaard Oeschger events?

http://www.ngdc.noaa.gov/paleo/icecore/greenland/summit/document/gispinfo.htm

The isotopic temperature records show 23 interstadial (or Dansgaard/ Oeschger) events first recognized in the GRIP record (Dansgaard et al., 1993) and verified in the GISP2 record (Grootes et al., 1993) between 110 and 15 kyr B.P. These millennial-scale events represent quite large climate deviations; probably many degrees C in temperature, twofold changes in snow accumulation, order-of-magnitude changes in wind-blown dust and sea-salt loading, roughly 100 ppbv in methane concentration, etc., with cold, dry, dusty, and low-methane conditions correlated (Alley et al, 1993; Taylor et al., 1993b; Mayewski et al, 1993c, 1994; Chappellaz et al, 1993).

These events are regional to global since they are observed in local climatic indicators such as snow accumulation rate and the isotopic composition of snow linked to temperature, in regional climatic indicators such as wind-blown sea salt and continental dust, and in regional-to-global indicators such as atmospheric concentrations of methane, nitrate and ammonium. Reorganizations of atmospheric circulation are indicated clearly (Mayewski et al, 1993c; 1994b; Kapsner et al, 1995).

So we it seems that we had enormous climatal upheaval in the 60ky -25ky BP timeframe. If a few degrees temperature change of Thomas in several decades is good for 25% how about 23 events of more than 10 degrees temperature change within a decade. Wouldn't it be good for 23 x 25% extinctions at least. So, did we have mass extinctions? I couldn't find any other than the previous mentioned P-H event.

So how many species became extinct during the transition to the assumed Eemian interglacial 130-135 Ky ago, that was as fierce as the transition to the Holocene? I couldn't find anything going on.

How about the other some 8 interglacials in the last million years, much upheavel in climates but mass extinctions? Please show them to me.

Another marked climate upheaval was the Paleocene/Eocene boundary (~55 Ma) when it was believed that massive CO2 discharges from oceanic clathrate caused a severe global climate change. So when was the last mass extinction? right the K-T boudary 65 Mya. 55 My ago mammal species were emerging rapidly taking the niches that the dino's left behind. No mass extinction.

It is incredible, nay, infuriating, that this paper past the peer review. But as long as you support the erratic anthropogenic global warming theory, you can just about say anything, but in the mean time science succumbs.

 

[FZ+]

If we agree with the popular asteroid theory for the Dinosaur extinction, it was the climate changes following the impact that was responsible for the actual extinction. The top level which was vulnerable to such changes were wiped out. What was left was species with greater redundancy and survivability, which would be able to resist better later changes in environment, until such characteristics were lost during evolution.

 

[Nereid]

Welcome back FZ+! Been a while.

There's another thread on this topic, over in Biology. Your views are always welcome, esp as Bystander and Russ may have become a little stuck. (Please read the whole thread).

BTW, we're looking at all 5 previous (?) mass extinctions; first step being to see (and agree, if possible) if we're in the midst of #6. Only then will we look for a cause or three.

Tonight's puzzle - where's Evo's Belgian chocolate?

 

[Andre]

Okay but what is the relationship?

We have a mass extinction, and we see climate changes. So the mass extinctions are caused by climate changes.

Would that make this true?

"We have climate changes, consequently we have mass extinctions."

As stated, there have been multiple alleged violent climate changes in the recent geologic past -much more intense and abrupt than the envisioned one now- with no unusual extinction rates corrolated.

Mankind doesn't need a climate excuse for justifying its impact on the environment. It can do it all by itself. Consequently it is most unlikely that cutting back CO2 emission is going to save a single species. If we want to preserve species, then we should preserve them directly. We cannot control climate. That's a farce.

 

[Nereid]

All good points Andre.

Assuming that we observe a mass extinction, you'd be as interested as I would in understanding what the causes of the extinction were (OK, I'm assuming about you too).

Perhaps there are multiple, interlocking causes? Perhaps climate change is merely the coup de grace, following widespread habitat fragmentation?

One step at a time.

Separate line of enquiry - is the climate changing? Assuming that we observe that it is, what are the causes?

 

[Bystander]

Originally posted by Nereid

Separate line of enquiry - is the climate changing? Assuming that we observe that it is, what are the causes?

"In for a penny, in for a pound." Go for it --- keeps us all off the street. Same rules?

 

[Andre]

Sorry, I've overlooked your post Nereid, responding to FZ+

Yes. I'm concerned too, but regarding the alleged anthropogenic climate changes I have followed my own way. About interpretation of evidence that is. Of course if habitat change, due to changing climate, species may become extinct.

Take the Wooly Mammoth (Mammuthus Primigenus) and its friends, the wooly Rhino, the musk ox, horses for instance. It's habitat was grassy arid steppe, feeding solely on grass (Pocaea). The onset of the Holocene (11,500 BP) was assumed to be global warming after the ice age but in Siberia we see a change of habitat from steppe to swamps as witnesned by the peat bogs. Both could exist within the same temperature regime but with different moisture. Hence not warming but a dramatic increase in precipitation would be a much better interpretation of the evidence for destroying the steppe habitat.

I'm saying that it is much more complicated than it looks.

 

[Nereid]

Originally posted by Bystander
"In for a penny, in for a pound." Go for it --- keeps us all off the street. Same rules?

I'd like to be the bystander on that one; or, rather, have someone else take the lead. Maybe in Earth? (although there's an very long thread there on EE that will be taking some of my time to address). Would you like to start?

 

[Nereid]

Andre wrote: I'm saying that it is much more complicated than it looks.

Ain't that the truth

 

[Andre]

Ain't that the truth?

But the big public, led by a scientific group, knows their own oversimplified brainwashed truth: mankind is destroying the climate and upheaval will follow. Emission of greenhouse gasses causes global warming and we should stop burning fossile fuels immediately. Simple and straightforward and we don't need any more. You have to repeat that several times a day in the papers and on television, if you want to get credibility and social acceptance. And condemned is he who dares to raise doubts that simple theory.