How likely is it that Global Warming will destroy human civilization within the next century?

[bananas]

ClimateProgress asks the tough questions:

How likely is it that Global Warming will destroy human civilization within the next century?

How desperate is the conservative pollster Rasmussen to glom onto the climate issue and both trivialize and confuse the debate with hyperbole, unscientific polls, and inane, vaguely worded questions? Pretty damn desperate, to judge by their headline poll last Thursday:

23% Fear Global Warming Will End World - Soon

Nearly one-out-of-four voters (23%) say it is at least somewhat likely that global warming will destroy human civilization within the next century. Five percent (5%) say it’s very likely.

Uhh, what does this polling question mean anyway:

How likely is it that Global Warming will destroy human civilization within the next century?

I mean, even I don’t think I’d answer that “very likely” or “somewhat likely” — and I think we face Catastrophic 5-7°C warming by 2100 on current emissions path. This is the territory of James Lovelock (see “Lovelock: Malthus was right, and Climate Progress is way, way too optimistic” and “James Lovelock turns everyone into a climate optimist“).

<snip>

[OKIsItJustMe]

1. Well, that depends

I think that extinction due to extreme climate change is a distinct possibility. For example, if we lose the oceans, we're pretty much done for.

On the other hand—since I know you're concerned about an all-out Nuclear War—one of my concerns is that social pressures, caused by climate change will lead to large-scale warfare (perhaps even nuclear warfare.)

[muriel_volestrangler]

3. What do you mean by 'lose the oceans'?

Some change is inevitable in them; but they're not going to disappear, and there will still be life in them, even if species have to migrate, for instance.

[Barrett808]

4. It will be single-celled life -- "The future is bright for dinoflagellates"

-- Dr. Jeremy Jackson, Scripps Institue of Oceanography

[Nihil]

8. I suspect he meant "Canfield Oceans" ...

... w.r.t. "Under a Green Sky" ...

The oceans (as in "large bodies of water") are not going to disappear
but most current forms of marine life would not be supported by a
Canfield Ocean.

At the moment, it is still on the extreme edge of possible futures
but once the methane starts getting released in large volumes from
hydrates, that chance becomes far larger.

[OKIsItJustMe]

10. Long-term ocean oxygen depletion in response to carbon dioxide emissions from fossil fuels

http://www.nature.com/ngeo/journal/v2/n2/abs/ngeo420.html

Letter abstract

---

Nature Geoscience 2, 105 - 109 (2009)
Published online: 25 January 2009 | doi:10.1038/ngeo420

Subject Categories: Climate science | Biogeochemistry | Oceanography

Long-term ocean oxygen depletion in response to carbon dioxide emissions from fossil fuels

Gary Shaffer^1,2,3, Steffen Malskær Olsen^3,4 & Jens Olaf Pepke Pedersen^3,5

Ongoing global warming could persist far into the future, because natural processes require decades to hundreds of thousands of years to remove carbon dioxide from fossil-fuel burning from the atmosphere^{1, 2, 3}. Future warming may have large global impacts including ocean oxygen depletion and associated adverse effects on marine life, such as more frequent mortality events^{4, 5, 6, 7, 8}, but long, comprehensive simulations of these impacts are currently not available. Here we project global change over the next 100,000 years using a low-resolution Earth system model⁹, and find severe, long-term ocean oxygen depletion, as well as a great expansion of ocean oxygen-minimum zones for scenarios with high emissions or high climate sensitivity. We find that climate feedbacks within the Earth system amplify the strength and duration of global warming, ocean heating and oxygen depletion. Decreased oxygen solubility from surface-layer warming accounts for most of the enhanced oxygen depletion in the upper 500 m of the ocean. Possible weakening of ocean overturning and convection lead to further oxygen depletion, also in the deep ocean. We conclude that substantial reductions in fossil-fuel use over the next few generations are needed if extensive ocean oxygen depletion for thousands of years is to be avoided.

---

1. Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, 2100 Copenhagen, Denmark
2. Department of Geophysics, University of Concepcion, Casilla 160-C, Concepcion 3, Chile
3. Danish Center for Earth System Science, Gl Strandvej 79, 3050 Humlebæk, Denmark
4. Danish Meteorological Institute, Lyngbyvej 100, 2100 Copenhagen, Denmark
5. National Space Institute, Technical University of Denmark, Juliane Maries Vej 30, 2100 Copenhagen, Denmark

Correspondence to: Gary Shaffer^1,2,3

e-mail: [e-mail]

[OKIsItJustMe]

11. Carbon isotopic evidence for chemocline upward excursions during the end-Permian event

http://dx.doi.org/10.1016/j.palaeo.2006.11.010

Carbon isotopic evidence for chemocline upward excursions during the end-Permian event

Anthony Riccardi^a, , Lee R. Kump^a, Michael A. Arthur^a and Steven D'Hondt^b

^aDepartment of Geosciences and NASA Astrobiology Institute, The Pennsylvania State University, University Park, PA 16802, United States

^bGraduate School of Oceanography and NASA Astrobiology Institute, University of Rhode Island, Narragansett, RI 02882, United States

Received 1 March 2006;  revised 17 November 2006;  accepted 24 November 2006.  Available online 16 January 2007.

Abstract

A negative shift in marine inorganic carbon-isotope composition (δ¹³C_carb) during the end-Permian mass extinction has been used as evidence for several different extinction mechanisms. Changes to the δ¹³C of organic matter and the difference between it and δ¹³C_carb (Δ¹³C = δ¹³C_carb − δ¹³C_org) have been examined at few locations, with conflicting interpretations. We examine the changes to both organic and inorganic carbon isotopes across the Permian–Triassic boundary at two marine sections from South China (Meishan and Shangsi) and compare these to data from other previously published sections. Through these analyses, we demonstrate that a decrease in Δ¹³C occurred during the extinction event throughout the Paleo-Tethys ocean. The extent and intensity of the decrease varies by location averaging a negative shift of ~ 5‰. Several possibilities as to the cause of this shift exist including Siberian trap volcanism, a change in the terrestrial/marine organic carbon input to the system, or a change in the dominant marine biota brought about through environmental changes (such as widespread ocean anoxia/euxinia). The decrease in Δ¹³C observed at many of these sections across the event horizon is here interpreted to represent a shift from algae/cyanobacteria to less fractionating phototrophic sulfur bacteria in marine shelf environments resulting from upward excursions of the chemocline. These chemocline upward excursions would release euxinic water to the photic zone allowing phototrophic sulfur bacteria to thrive. The limited available biomarker data are consistent with this interpretation.

Keywords: Permian; Triassic; Mass extinction; Carbon-isotope

[OKIsItJustMe]

12. Rising Acidity Threatens Oceans - “Severe damages are imminent”

http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=115&topic_id=184849&mesg_id=184849

[OKIsItJustMe]

13. Scientists Discover Global Pattern of Big Fish Diversity in Open Oceans

http://earthobservatory.nasa.gov/Newsroom/view.php?id=27569

Scientists Discover Global Pattern of Big Fish Diversity in Open Oceans

July 28, 2005

A new study released in Science (via Science Express) on July 28th reveals a striking downward trend in the diversity of fish in the open ocean—the largest and least known part of our planet. Teasing apart the effects of climate change and fishing over the past 50 years, the authors show a clear link to overfishing and highlight a surprising global pattern of open ocean hotspots—areas with predictable congregations of tuna, marlin, swordfish, and other ocean predators.

Scientists say these hotspots—off the east coasts of the U.S., Australia, and Sri Lanka; south of Hawaii; and in the South-Eastern Pacific—provide new insight into the structure of life in the open ocean and a focus for conservation efforts. Perhaps most surprising is the discovery that patterns of big fish diversity match those for tiny zooplankton, and both are linked to sea surface temperature. “This is the great joy of science,” says first author Boris Worm. “It is like solving a giant puzzle and seeing the night sky in constellations for the first time—even as the stars are blinking out. It’s beautiful—and tragic at the same time.”

In a sequel to their groundbreaking study in Nature in 2003, showing the depletion of 90% of the big fish in the ocean, co-authors Boris Worm and Ransom Myers of Dalhousie University reveal that overfishing has not only reduced the number of fish in the sea, but also the variety: the diversity of tuna, marlins, and swordfish in the oceans has declined by up to 50% in the last 50 years.

“Everywhere you go, in every ocean basin, our “hotspots” today are only relics of what was once there,” says Worm. “It really hurts to see this.”

…

[OKIsItJustMe]

14. Over Fishing Changes Food Webs

http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=115&topic_id=141791&mesg_id=141879

[OKIsItJustMe]

15. Toxic Deep-Ocean Water Triggered "Great Dying"

http://news.nationalgeographic.com/news/2007/11/071126-mass-extinction.html

Toxic Deep-Ocean Water Triggered "Great Dying"

Helen Scales
for National Geographic News
November 26, 2007

The finger of blame for the greatest mass die-off in Earth history points to a slow, drawn-out demise that came from below, a new study shows.

Researchers discovered that bryozoans—a common type of colonial marine creature also known as "moss animals"—began slowly declining in oceans across the world many millions of years before the mass-extinction event at the end of the Permian period about 251 million years ago.

This so-called Great Dying event wiped out about 90 percent of marine species and 70 percent of land species.

…

The most likely culprit for the gradual bryozoan die-offs was the upwelling of toxic water unleashed from the deep ocean by rising global temperatures.

…

"So it is likely that toxic fumes of hydrogen sulfide diffused out of the oceans, land-based animals, which plummeted by 70 percent in the same mass extinction event."

…

[OKIsItJustMe]

16. How overfishing can alter an ocean’s entire ecosystem

http://features.csmonitor.com/environment/2008/06/19/how-overfishing-can-alter-an-ocean%E2%80%99s-entire-ecosystem/

How overfishing can alter an ocean’s entire ecosystem

When you tip the balance, a cascade of other changes may occur.

By Moises Velasquez-Manoff | Staff writer of The Christian Science Monitor/ June 19, 2008 edition

New York

In 2000, University of Maine graduate student Amanda Leland began a seemingly straightforward restoration project. She transported 24,000 young sea urchins, which are native to the Gulf of Maine, to an area where overharvesting had caused them to disappear. She expected to watch them thrive and repopulate. But something else happened: An army of Jonah crabs arrived and, within a month, the hand-sized predators had devoured the urchins.

Ms. Leland repeated the experiment the following year. But this time she transplanted the urchins in spring, months before the crabs’ fall migration. They thrived as expected – until August when the crabs showed up. By Sept. 1, they were gone. Leland thought she knew why. With cod and other groundfish gone, Jonah crabs were four times more abundant than in times past.

“There really aren’t many crab predators left,” says Leland, now the Environ­ment­­al Defense Fund’s national policy director of oceans in Washington. “They have been released from predation control.”

Scientists have documented versions of this story around the world. Overfishing has shifted entire ecosystems with often surprising, and occasionally unpleasant, results. In the tropics, seaweed often dominates where coral once reigned. Around the world, jellyfish and algae proliferate where finfish previously dominated. With big predators often gone or greatly depleted, organisms lower on the food web grow more abundant, reducing their own prey in turn.

…

[Annces]

2. Or put another way - how long before human civilization destroys itself

Humans are the creators of global warming.

[Barrett808]

5. I'd substitute "severely constrain" for "destroy"

But for most of us, the distinction will be academic.

[GliderGuider]

6. In the sense that Rome was "severely constrained"?

The species will be severely constrained. I'm becoming less and less confident about the survival of anything resembling civilization as we know it.

[pscot]

7. A better than even chance

But I won't be here to see it (unless, of course, it happens a lot faster than expected).

[One_Life_To_Give]

9. Depends how Civilization is defined

The complete elimination of Homosapiens is highly unlikley, even a total nuclear exchange between the US and Russia would be unlikely to kill every last individual. However what our civilization may look like in 100 years time has a wide range of possibilities. I would guess we have a decent probability that much of humanity will be in a dark age. Global population of less than 1 Billion. With isolated pockets of people who still know/understand what was and can use what remains but are unable to fashion significant quantities of tech items.

[sofa king]

17. That's a lot like the way I was thinking.

This civilization is doomed as of this moment, for as a matter of course it will change over time until it is very different. It will change faster or slower in part due to climate change.

There are plenty of other factors at work, though. Five billion people are dependent upon a steady supply of oil for their sustenance, and if that is interrupted most of them could be gone in a matter of months. That in turn will dramatically reduce hydrocarbon emissions, which might change the climate again. If the decline in oil production is slower, a still-huge population will be living on the bubble, in poor health and vulnerable to diseases both natural and tailored.

One way or another, six billion people are going to die this century, for very few of us alive today will live to see the next one. If we're replaced--or even doubled, as some predict--by our successors, they will have a much rougher time of it. If we're not replaced, civilization itself will have to contract, with unpredictable results.

[OKIsItJustMe]

18. I'm not confident of us even doing that well

It's possible that we may have kicked off the equivalent of the "http://en.wikipedia.org/wiki/Permian%E2%80%93Triassic_extinction_event">Great Dying." If true, then this is going to be a very unfriendly place to live for a long time. (Well… probably much friendlier than Mars… but as compared to the sweet Mother Earth we grew up with?)

[tom_paine]

19. I think the question is not if human civilization will be destroyed, but if human beings will go

extinct

The issue is timeline. The human species might last another 5,000 or 10,000 years. I mean, I have read books on paleo-climatology that some of our ancestors in the last 1,000,000 years faced some hurricanes and storms that were HUGE compared to today.

In the Cretaceous Period, I read where the hurricanes were so big they left hummock in the OCEAN FLOOR.

My point is, that huge storms and global warming have happened before and species survived, though not well. A complex higher organism like human beings may or may not be able to survive at Stone Age levels in such an environment.

I guess that's my point: human civilization destroyed (reduced to Bronze or Stone Age?) by 2100? I'd say, and this is probably an optimistic assessment: 80% chance.

That other 20% comes in the form of if the effects of both Peak OIl and GW are relatively slow, rather than a STEEP decline in oil and a STEEP warming. It could be that one is fast and the other slow (thanks GliderGuider, for finding that analysis and perspective and bringing it to E/E). Which would also delay the destruction of human civilization.

Gonna be a rough ride no matter what. Increase the timeline to 200 year for human civilization destroyed and it rockets up to 99.99999999999999999%, I think.

Human beings have surprised ourselves before, though, and maybe their's one more technological rabbit to pull out of the hat, but given the scope of our problems, that seems wildly unrealistically optimistic.

The REAL questions are:

1) How LONG will the climate and ecosystem be destabilized until it reaches a new equilibrium?

2) Will the new environmental and ecological equilibrium be able to support human beings, probably at Stone or Brone Age technical levels?

How LONG do we have to wait before the climate, once unleashed to Cretecaous levels of atmospheric disturbance, will find it's way back to something "civilization" can rebuild, hopefully with more foresight than this time around.

Actually, there's other questions: What about the massive amounts of plastics, as over time they enter and disperse further throughoutthe ecosystem and us?

Will the metals situation, the fact that we've dug it all up and it's rusting/oxidizing and we haven't the technology, preclude even a retunr to the Bronze Age?

It's gonna get ugly.