New report blames heat for ancient extinction

[bananas]

Source: Xinhua

Chinese, British and German scientists have discovered that the worst extinction of the Earth's history happened because the planet was simply too hot to survive.

The discovery about the end-Permian mass extinction, which wiped out the world's species 250 million years ago and was followed by a "dead zone" of five million years in which the planet welcomed no new species,came in a paper published on Friday in Science, one of world's top scientific journals.

The joint study by the China University of Geosciences in Wuhan, capital of central China's Hubei Province, the University of Leeds in Britain and the University of Erlangen-Nuremburg in Germany, shows the cause of the lengthy devastation was a temperature rise to lethal levels: around 50 to 60 degrees Celsius on land, and 40 degrees Celsius at the sea-surface.

<snip>

Professor Paul Wignall from the School of Earth and Environment at the University of Leeds, one of the study's co-authors, said: "Nobody has ever dared say that past climates attained these levels of heat. Hopefully future global warming won't get anywhere near temperatures of 250 million years ago, but if it does we have shown that it may take millions of years to recover."

<snip>

Read more: http://www.shanghaidaily.com/article/article_xinhua.asp?id=102733

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Another article has this graphic:

http://io9.com/5953178/triassic-eras-extreme-heat-created-dead-zones-across-the-planet

Triassic era’s extreme heat created “dead zones” across the planet


A paleogeographic reconstruction of the Early Triassic world (Smithian substage) around 252 to 247 million years ago, showing a ‘dead zone' in the tropics. Marine reptiles (ichthyosaurs), terrestrial tetrapods and fish almost exclusively occurred in higher latitudes (>30 °N and >40 °S) with rare exceptions. Credit: Yadong Sun, University of Leeds.

<snip>

And indeed, life had no choice but to react to this heat. It's suspected that marine life swam to the polar regions to keep cool. Similarly, terrestrial animals also headed to the extreme north and south. Back then, the mega-continent Pangea existed, making Antarctica/Australia and Siberia likely areas for re-habitation.

Meanwhile, the tropical regions would have been bizarre places to visit. These areas would have been very wet, but with very few plants growing — only shrubs and ferns. These ares would have been devoid of most terrestrial creatures. And in the waters, only shellfish would have stuck around.

What happened? Essentially, the superhot Earth was caused by a breakdown in global carbon cycling. Normally, plants help regulate temperature by absorbing CO2 and burning it as dead plant matter. But without plants, the CO2 levels rose unchecked, causing a spike in temperatures. Specifically, the researchers estimate that at least 12×10^3 gigatons of isotopically depleted carbon as methane was injected into the atmosphere.

To reach this conclusion, the scientists collected data from over 15,000 conodonts (tiny teeth of eel-like fishes). By analyzing the isotopes of oxygen in these remnants, they were able to determine the temperature levels hundreds of millions of years ago. You can read the entire study at Science.

[bemildred]

1. That's the one.

Thanks for posting. That's really hot.

[frogmarch]

2. Thank you!

I'm going to check out the link now.

Exciting study!

[bananas]

9. Unfortunately, the paper in Science is paywalled

Science has the paper and a perspective article on the paper, both paywalled.

http://www.sciencemag.org/content/338/6105/366.abstract

Science 19 October 2012:
Vol. 338 no. 6105 pp. 366-370
DOI: 10.1126/science.1224126

Report

Lethally Hot Temperatures During the Early Triassic Greenhouse

Yadong Sun1,2,*,
Michael M. Joachimski3,
Paul B. Wignall2,
Chunbo Yan1,
Yanlong Chen4,
Haishui Jiang1,
Lina Wang1,
Xulong Lai1

Abstract

Global warming is widely regarded to have played a contributing role in numerous past biotic crises. Here, we show that the end-Permian mass extinction coincided with a rapid temperature rise to exceptionally high values in the Early Triassic that were inimical to life in equatorial latitudes and suppressed ecosystem recovery. This was manifested in the loss of calcareous algae, the near-absence of fish in equatorial Tethys, and the dominance of small taxa of invertebrates during the thermal maxima. High temperatures drove most Early Triassic plants and animals out of equatorial terrestrial ecosystems and probably were a major cause of the end-Smithian crisis.

Received for publication 1 May 2012.
Accepted for publication 4 September 2012.

http://www.sciencemag.org/content/338/6105/336.summary

Science 19 October 2012:
Vol. 338 no. 6105 pp. 336-337
DOI: 10.1126/science.1228998

Perspective

Geochemistry
Life in the Early Triassic Ocean

David J. Bottjer

In the next 100 years, it is projected that Earth will move to a greenhouse climate state (1). The future ocean will not only be hotter but also more acidic and will contain extended zones with reduced oxygen (2, 3). Study of past periods of global warming helps to project what Earth and its biota will be like in this new state and what the journey to that state will entail. On page 366 in this issue, Sun et al. (4) show that beginning with the end-Permian mass extinction (∼252.6 million years ago) and continuing for the next 5 million years, Earth's oceans were extremely hot, with stressful and commonly lethal effects on ocean life.

[frogmarch]

21. Thank you. nt

[bananas]

10. io9 links to the wrong paper

The io9 article links to a paper published last July, which is also paywalled.

http://www.sciencemag.org/content/333/6041/430.abstract?sid=39695b89-79f0-4b26-83c9-ea4db742ed62

Science 22 July 2011:
Vol. 333 no. 6041 pp. 430-434
DOI: 10.1126/science.1204255

Report

Atmospheric Carbon Injection Linked to End-Triassic Mass Extinction

Micha Ruhl1,2,*,
Nina R. Bonis1,3,
Gert-Jan Reichart4,
Jaap S. Sinninghe Damsté4,5,
Wolfram M. Kürschner1,6

Abstract

The end-Triassic mass extinction (~201.4 million years ago), marked by terrestrial ecosystem turnover and up to ~50% loss in marine biodiversity, has been attributed to intensified volcanic activity during the break-up of Pangaea. Here, we present compound-specific carbon-isotope data of long-chain n-alkanes derived from waxes of land plants, showing a ~8.5 per mil negative excursion, coincident with the extinction interval. These data indicate strong carbon-13 depletion of the end-Triassic atmosphere, within only 10,000 to 20,000 years. The magnitude and rate of this carbon-cycle disruption can be explained by the injection of at least ~12 × 103 gigatons of isotopically depleted carbon as methane into the atmosphere. Concurrent vegetation changes reflect strong warming and an enhanced hydrological cycle. Hence, end-Triassic events are robustly linked to methane-derived massive carbon release and associated climate change.

Received for publication 14 February 2011.
Accepted for publication 1 June 2011.

[frogmarch]

22. sheesh! Thanks again. My company left and

I was just getting ready to read it.

[msongs]

3. so life should have evolved to meet the new conditions...ooops nt

[nichomachus]

4. So, basically, kind of a "do over"

Not a bad idea at all.

[aquart]

5. Going into global warming, that's just lovely.

Can we please carve all of Shakespeare into stone in at least three different forms of writing?

[kentauros]

12. But where would you put it

that the elements wouldn't get to it? Even underground isn't safe enough.

Better to "write" it in carbon nanotubes and Buckyballs as that's one thing we've invented that persists in the environment.

[closeupready]

6. 1) Heat wave; 2) boom in air conditioner manufacturing;

3) Profit! End of thread.

[dipsydoodle]

7. In the absense of that

it doesn't necessarily follow that we'd be here now.

[Rosa Luxemburg]

8. Thanks for sharing

[jimlup]

11. Uh Oh!

As stated by the co-pilot of the then doomed Challenger Space Shuttle.

[Spitfire of ATJ]

13. The time would be about 2:40 into this video.

[kentauros]

14. "Reduced Life Zones"

By their own words, even the so-called "dead zones" were far from dead:

Meanwhile, the tropical regions would have been bizarre places to visit. These areas would have been very wet, but with very few plants growing — only shrubs and ferns. These ares would have been devoid of most terrestrial creatures. And in the waters, only shellfish would have stuck around.

Personally, I'd like to see us put fungi to broader use in helping to keep the carbon cycle going. I don't think we can rely on the corporate world to help, so we'll have to figure out how to do it ourselves.

[Posteritatis]

20. 95-plus-percent biodiversity loss is pretty dead to me. (nt)

[kentauros]

23. 5% alive

aren't dead

As far as I'm concerned, a "dead zone" has no life, not even bacteria or viruses. And that's not likely in that scenario due to the fact that there are bacteria and viruses that live around underwater volcanic vents. 60C is cool water to them. Not to mention what lives in the air and the soils.

[starroute]

15. I wonder if it's related to the stuff in this other study

According to an article that appeared a few months ago, the Carboniferous ended and the Permian began because of the appearance about 290 million years ago of a fungus that could break down dead plant matter and return carbon to the atmosphere as CO2 instead of it being stored in the ground as coal.

http://grist.org/climate-energy/win-win-ancient-fungus-that-ended-coal-formation-could-boost-biofuel-production/

Now, this latest thing says that there was runaway warming about 250 million years ago. It sounds as though plants had been managing to keep recycling the carbon as fast as it was returned to the atmosphere -- but when the initial mass extinction event happened, there were no longer enough living plants to absorb the carbon from the dead ones, and things got out of hand.

I wonder, though, why later mass extinction events didn't have the same impact. Perhaps they weren't as severe -- bad enough to do in the dinosaurs but not otherwise as lethal. Or perhaps plants had gotten more resistant in the interim by developing seeds and other mechanisms that let them survive a disaster in dormant form.

[AverageJoe90]

19. The K/T event was actually worse than the Permian in ways.

But given the enormous amount of time elapsed between the Permian extinction and the K/T event, some plants may have indeed been able to better adapt to severe change in conditions.

The problem is, though, is that the KT event happened in the blink of an eye compared to the Permian. Not to mention the humongous firestorms that developed in much of the world after the impact due to ejecta and such. At least during the Permian, some species were able to adapt to rising temperatures and such. With the K/T event, only those that were able to rapidly adapt had any chance of survival at all, and, to be honest, it may be partly thanks to sheer chance that only 70% of species were wiped out, when it very well could have done in perhaps something like 90-95% of species; and if so, I would suspect the exact same thing might go the Permian era as well, just in the opposite direction(it wiped out about 85% of all species overall, but, it could have perhaps have been maybe perhaps half, or even less.).

It has also been argued that volcanic eruptions & bolide asteroid impacts, too, played a role in the Permian extinction:

http://www.pnas.org/content/early/2011/12/12/1118675109.abstract

[ErikJ]

16. "Siberian Traps" melted trapped methane?

From what I can tell the most accepted theory is that the massive flood basalts in Siberia, called the "Siberian Traps," which were the size of Europe and lasted for a million years melted vast quantities of frozen/trapped methane in shallow seas. The Siberian Traps were formed just prior to the Permian extinction.

[Agnosticsherbet]

17. Good idea to move north...

Way North.

[ErikJ]

18. Or high in the mountains. Very high.

[Spitfire of ATJ]

24. We could always become cavemen again.

How many times have we seen scifi where the inhabitants go underground when the surface becomes uninhabitable?