Global Warming: Earth 10,000 AD

a) the Earth is supposed to be getting cooler right now, not hotter, so assuming we curbed CO2 emissions it would be possible to see the recent warming phase reverse within a time frame of a few hundred years
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No - CO2 is persistent - that's something many overlook.

Nature Reports Climate Change
Published online: 20 November 2008 | doi:10.1038/climate.2008.122
Carbon is forever

Carbon dioxide emissions and their associated warming could linger for millennia, according to some climate scientists. Mason Inman looks at why the fallout from burning fossil fuels could last far longer than expected.

Distant future: our continued use of fossil fuels could leave a CO2legacy that lasts millennia, says climatologist David Archer
123RF.COM/PAUL MOORE

After our fossil fuel blow-out, how long will the CO2 hangover last? And what about the global fever that comes along with it? These sound like simple questions, but the answers are complex — and not well understood or appreciated outside a small group of climate scientists. Popular books on climate change — even those written by scientists — if they mention the lifetime of CO2 at all, typically say it lasts "a century or more"1 or "more than a hundred years".
"That's complete nonsense," says Ken Caldeira of the Carnegie Institution for Science in Stanford, California. It doesn't help that the summaries in the Intergovernmental Panel on Climate Change (IPCC) reports have confused the issue, allege Caldeira and colleagues in an upcoming paper in Annual Reviews of Earth and Planetary Sciences2. Now he and a few other climate scientists are trying to spread the word that human-generated CO2, and the warming it brings, will linger far into the future — unless we take heroic measures to pull the gas out of the air.
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more
http://www.nature.com/climate/2008/0812/full/climate.2008.122.html

We would actively have to pull carbon from the air and we know response is asymmetrical so we risk very odd consequences.

The problem with all these speculative endeavors we don't know what humans will do :boggled:

All we can tell is what is in the pipeline now which will take us somewhat outside the the Holocene range is we stopped cold turkey and no other large scale effect ( methane release ) is kicked off.

The orbital cooling trend is very slow compared to our impact on the warming side of the column.

Since all the assumptions cannot know either our activities or whether methane release occurs all will be highly speculative and can only show what if a certain amount or all of vulnerable glacial areas melt.

Hell, Holland is in deep trouble even with a couple of meters as is London, Florida, New York and and most of Bangladesh.
And Venice and New Orleans become a scuba diving paradise.

There is more C02 in the air right now than in 15 million years...there ARE consequences....we don't know the timing and extent of the consequences.
We are seeing some of them unfold right now. :boxedin:
 
zaphod2016 said:
Am I mixed up?

EDIT: assuming 18 feet rise per 1,000 years (according to NPR projections), we would expect sea levels to have risen 8*18=144 feet = ~44 meters

Is that a more reasonable estimate than 100m?
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Why would the process go linear? A range of 80-100m seems more reasonable for me as we know we don't have additional water (better leaving comets out) so it becomes the most probable outcome -just a relative term-.

At this point it looks like the limited stock of water packed as ice is the only aspect that prevent these reasonings from becoming something like "If I continue to lose one pound a week I'll disappear by June 2014" -my avatar was in such a business, maybe for a propensity to get the right answers for the wrong questions-. We may better analyze the issue as "Oceans: a raise of 45 meters by 10,000AD. Are there processes going on today that could cause that outcome? Which ones and why?"

I you asked me I would answer that there is plenty of people losing five pounds a week and by 10,000AD they'll be all dead, not slim.
 
macdoc said:
There is more C02 in the air right now than in 15 million years...
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Evidence for this claim? Is it Tripati-2009? If so, then it is contentious.

Found this...

"Your statement, "atmospheric CO2 is at its highest level in 15 to 20 million years (Tripati 2009)" is not justified by the reference. The Tripati et al CO2 time series estimates do not have the time resolution to say if any millennium's CO2 concentration might have exceeded the current levels of 2010. The time-averaging inherent in their technique will mask the peaks and valleys of CO2 concentration that occur in time periods shorter than their time resolution (which, according to Figure 2A/B, varies between roughly 100,000 and 1000,000 years). You could say that Tripati et al suggest that current levels are higher than the average of the last 15~20 million years. ""

http://www.skepticalscience.com/human-co2-smaller-than-natural-emissions.htm
 
Then contend it....

We are able, for the first time, to accurately reproduce the ice-core record for the last 800,000 years — the record of atmospheric C02 based on measurements of carbon dioxide in gas bubbles in ice," Tripati said. "This suggests that the technique we are using is valid.

"We then applied this technique to study the history of carbon dioxide from 800,000 years ago to 20 million years ago," she said. "We report evidence for a very close coupling between carbon dioxide levels and climate. When there is evidence for the growth of a large ice sheet on Antarctica or on Greenland or the growth of sea ice in the Arctic Ocean, we see evidence for a dramatic change in carbon dioxide levels over the last 20 million years.
"A slightly shocking finding," Tripati said, "is that the only time in the last 20 million years that we find evidence for carbon dioxide levels similar to the modern level of 387 parts per million was 15 to 20 million years ago, when the planet was dramatically different
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http://www.physorg.com/news174234562.html

From that same article

Prior to the Industrial Revolution of the late 19th and early 20th centuries, the carbon dioxide level was about 280 parts per million, Tripati said. That figure had changed very little over the previous 1,000 years. But since the Industrial Revolution, the carbon dioxide level has been rising and is likely to soar unless action is taken to reverse the trend, Tripati said.
"During the Middle Miocene (the time period approximately 14 to 20 million years ago), carbon dioxide levels were sustained at about 400 parts per million, which is about where we are today," Tripati said. "Globally, temperatures were 5 to 10 degrees Fahrenheit warmer, a huge amount." Tripati's new chemical technique has an average uncertainty rate of only 14 parts per million. "We can now have confidence in making statements about how carbon dioxide has varied throughout history," Tripati said.
In the last 20 million years, key features of the climate record include the sudden appearance of ice on Antarctica about 14 million years ago and a rise in sea level of approximately 75 to 120 feet.
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Analysis of likely scenarios based on our inability to control CO2 emissions show us heading towards +4 C or higher in a geologic eyeblink....
http://web.mit.edu/newsoffice/2009/climate-change-1002.html

How is that at odds with this

"Globally, temperatures were 5 to 10 degrees Fahrenheit warmer, a huge amount."
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So we have a reasonable hypothesis and experimental observation supporting the hypothesis.
We have a decently clear understanding of the physics of CO2 in the atmosphere and the feedback of water vapour magnifying and observational support of both.

We await your "contention" that any of

C02 levels were not that high at the time frame in the article
Global temps were not that high at the time frame in the article

are incorrect or unsupportable.

That leads us to the remaining hail mary
Something is different now than then leading to less ice loss......:rolleyes:

From where I stand we are headed towards a planet with a far smaller cryosphere and a very different looking set of coastlines - timing is the question. Not if but when.....:garfield:
 
One problem with any such map is the assumption of no negative feedback.
Whether we enter a new cooling period, for instance, might be critically dependant on the oceanic circulation of cold water.
Any massive melt of the Greenland cap will affect cold water formation in the N.Atlantic, pushing the Gulf Stream south, increasing Atlantic cloud formation, shoving planetary albedo up etc, etc.
Such feedback mechanisms might be expected to have braking effects on further melting.

Or in short- I think you'll find it's more complicated than that.

Incidentally, re isostatic rebound, rise of 10-30m in parts of northern Europe has happened over the last 10,000 years or so.
 
easycruise said:
The time-averaging inherent in their technique will mask the peaks and valleys of CO2 concentration that occur in time periods shorter than their time resolution (which, according to Figure 2A/B, varies between roughly 100,000 and 1000,000 years). You could say that Tripati et al suggest that current levels are higher than the average of the last 15~20 million years.
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What "technique" did you have in mind at the time of writing/reading it? You have here the supporting on-line material for Tripati et al, including "A- Samples, analyses and analytical uncertainty".

I think you may develop your idea a bit more, or at least find more sources o a more authoritative source. You are getting an answer to comment 37 in a web blog, and forgive me but "contentious" sounds a bit bombastic once the source is weighed.
 
plumjam said:
Thanks to everyone for the imaginary-world heads up.
Now I have eight thousand years to find a hill to live on.
Plus, fish will be cheaper, (though you never know, with inflation).
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Actually fish may well be quite rare and thusly likely more expensive.
 
TShaitanaku said:
Actually fish may well be quite rare and thusly likely more expensive.
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Species evolve to fill all available niches. 10,000 years equals 10,000 generations of pescas. Hmmm, 500 generation of humans too.

Not to mention a phenomenon called "thermoclines", where in the warm water stays on the surface, and the cooler water and lots of fish are 10 feet down. I've sure snorkled in 90F water, dove down a few feet and got a frosty chill.

Just think of the flounders t6hat will live on the Texarkana Bank...
 
casebro said:
TShaitanaku said:
Actually fish may well be quite rare and thusly likely more expensive.
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Species evolve to fill all available niches. 10,000 years equals 10,000 generations of pescas. Hmmm, 500 generation of humans too.
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Are you implying that species evolve to continue to be an awful lot of individuals and keep high levels of supply? I suppose TShaitanaku was thinking about a lower level of oxygen in warmer sea waters,
 
In the upper regions it won't matter much--oxygen will be at or nearly at equilibrium with air for the surface water (my guess would be halfway down the column affected by waves, but it's a guess). The real limiting factor will be (as it is now) nutrient load. The areas of the sea with a lot of life are also the areas with a high nutrient load due to upwelling (deep water disolves key nutrients from the ocean floor and brings them to the surface). Change the shape of the seas, change the thermohaline circulation, and you change upwelling zones.

All that said, fish survived the Permian Mass Extinction. I'm betting that while they take a hit, they'll be fine in the long run. The issue isn't "will there be fish", but rather "will there be edible/economically viable fish?"
 
casebro said:
Species evolve to fill all available niches. 10,000 years equals 10,000 generations of pescas. Hmmm, 500 generation of humans too.

Not to mention a phenomenon called "thermoclines", where in the warm water stays on the surface, and the cooler water and lots of fish are 10 feet down. I've sure snorkled in 90F water, dove down a few feet and got a frosty chill.

Just think of the flounders t6hat will live on the Texarkana Bank...
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There are a number of factors to account for, most of them seem to indicate a decline in most food fish species over the next few decades to centuries.

Global fish production and climate change - http://www.pnas.org/content/104/50/19709.full.pdf+html

"Vulnerability of national economies to the impacts of climate change on fisheries" - http://www.csrglobal.cn/upload/image/301734.pdf

Large-scale redistribution of maximum fisheries catch potential in the global ocean under climate change - http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2486.2009.01995.x/abstract
 
Then again Murphy and his lovely law can take a hammer to all our speculation and some volcanoes can blow one into our lovely theories...
 
aleCcowaN said:
Are you implying that species evolve to continue to be an awful lot of individuals and keep high levels of supply? I suppose TShaitanaku was thinking about a lower level of oxygen in warmer sea waters,
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There are a lot of factors to consider, and though I wasn't really meaning to talk about complete extinctions of all fish (thus the "quite rare and thusly likely more expensive") but rather that the fisheries shift or are generally less productive in warmer global climates and the many areas that currently depend on local area fleets for a substantial portion of the population's diet,...are gonna have a hungry local population.

But back to the extinction line of thought, there is this: A long-term association between global temperature and biodiversity, origination and extinction in the fossil record - http://rspb.royalsocietypublishing.org/content/275/1630/47.full
 
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The Deccan Traps contributed to the K/Pg mass extinction.

Yellowstone could wipe out much of the United States (not with the eruption, but with the fallout and secondary effects), rendering it all irrelevant to those of us who live in the USA. When your country collapses you don't worry about sea level rise.
 
Nosi said:
Vulcanism can lower tempature by poluting the air with small particulate matter. "The year without a summer" was caused by a big eruption.
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What, you think that "our lovely theories" don't take vulcanism into account? :confused:

Dinwar said:
The Deccan Traps contributed to the K/Pg mass extinction.

Yellowstone could wipe out much of the United States (not with the eruption, but with the fallout and secondary effects), rendering it all irrelevant to those of us who live in the USA. When your country collapses you don't worry about sea level rise.
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Yes, but unlike Yellowstone we KNOW that sea level will rise within one or two hundred years, whereas Yellowstone might not blow for thousands of years yet. As a gambling man I know where I'd be putting my coin, in terms likelihood.
 
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Nosi said:
Vulcanism can lower tempature by poluting the air with small particulate matter. "The year without a summer" was caused by a big eruption.
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Indeed, but I don't see how this would "...take a hammer to all our speculation and some volcanoes can blow one into our lovely theories...".

a cool hemisphere for a year or two due to a truely massive eruption, would neither make global warming "go away," nor would it be a cause for changing our understandings and considerations.
 
Vulcanism PROVES our "lovely theories" about climate forcings are, in fact, quite correct.
 
Yes, but unlike Yellowstone we KNOW that sea level will rise within one or two hundred years, whereas Yellowstone might not blow for thousands of years yet. As a gambling man I know where I'd be putting my coin, in terms likelihood.
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Not disagreeing with you. Seeing as how Yellowstone's been moving up and down a bit more than I'd like I'm not discounting the idea that it'll go boom, but then again "more than I'd like" translates roughly to "at all" in this case. :)

Vulcanism can lower tempature by poluting the air with small particulate matter. "The year without a summer" was caused by a big eruption.
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The particulates (and sulfides [sulfates?]) temporarily cool the planet. The CO2, methane, water vapor, and other chemicals released warm the planet. The cooling lasts for a short time, while the warming lasts substantially longer.

What, you think that "our lovely theories" don't take vulcanism into account?
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All the models I've seen tend to ignore volcanism, unless they're specifically built to look at the effects of volcanism. With as random as eruptions are it's hard to predict them. I mean, the small ones (Hawaii, the vents in the deep sea, etc--small in terms of property destruction, not necessarily output) are probably factored in as part of the overall CO2 increase in most models, meaning it's dealt with as more or less a constant amount and therefore doesn't change over time. A major eruption--a cauldera or Krakatoa (Mt. St. Helens doesn't count)--would substantially alter our GCMs, one way or another (usually not the direction AGW deniers would like).
 
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