EnviroLink Forum

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With friends like Guido, you will not have enemies for long.

“Intellect is invisible to the man who has none”
Arthur Schopenhauer

"The difference between genius and stupidity is that genius has its limits."
Albert Einstein

Infinite runaway is not the 'Venus Effect', and really impossible. With Earth being farther away from the Sun, the oven would be half as hot, or so. The only CO2 'tipping point' is when it gets hot enough to be released from solution and rock to a half mile deep.
The sequence of HGHGs to warming enough for open ocean warming to be self sustaining, leading to tundra methane and other GHG releases, with more warming from that leading to deep ocean methane self release. Self release is just when outside feedbacks are no longer necessary for the process to continue, that is when the positive feedback loops are formed.
The last being CO2 in the top paragraph sentence.
I hope that open ocean warming does not trigger the methane self release monster, and that there is still time to reverse course (eventually) with massive HGHG reduction within a short time. From what I remember, the probability of that working is 50/50.

_________________
"With every decision, think seven generations ahead of the consequences of your actions" Ute rule of life.
“We do not inherit the earth from our ancestors; we borrow it from our children”― Chief Seattle
“Those Who Have the Privilege to Know Have the Duty to Act”…Albert Einstein

_________________
With friends like Guido, you will not have enemies for long.

“Intellect is invisible to the man who has none”
Arthur Schopenhauer

"The difference between genius and stupidity is that genius has its limits."
Albert Einstein

I don't know of any rule that says feedback can only refer to water vapor and CO2. If methane and melting ice want to join the party then that's all right too. The point is without an outside force like man the feedbacks steadily diminish to equilibrium. No runaway.

_________________
With friends like Guido, you will not have enemies for long.

“Intellect is invisible to the man who has none”
Arthur Schopenhauer

"The difference between genius and stupidity is that genius has its limits."
Albert Einstein

_________________
With friends like Guido, you will not have enemies for long.

“Intellect is invisible to the man who has none”
Arthur Schopenhauer

"The difference between genius and stupidity is that genius has its limits."
Albert Einstein

Wayne S; "No and huge amounts of water vapor which also has a net warming, there is a finite amount of carbon which can be released by humanity and that would not cause a runaway as you have defined it. This is especially true if humans become extinct in the process."

That is not true. The amount of HGHGs is already beyond the open ocean warming tipping point. In fact, since 2007, we have been in runaway with that. The amount of sequestered carbon is between 100 and 1000 times the amount humans have burned to start the processes. Burning the last 50% quickens the turnover.
It is not linear so 100 times the atmospheric carbon is more than 100 times the .7*C plus the increase in the form of 'momentum'. That much is enough to release all the carbon sequestered. The atmosphere is hot enough to boil away the oceans and heat the earth to depths of geologic heating. 200*C or more. No more life on Earth, ever again.
So if even an immediate human population crash will not change it, what could?. What is needed is plenty of atmospheric aerosols for long enough to cool the atmosphere and oceans.
In the past, super volcanoes have caused bottlenecks with ~5*C cooling for a decade or two as aerosols fall out.
Even if humans had a population crash and emissions went way down immediately, it does not stop the warming waters from causing more atmospheric and hard earth temperature rise at depth, leading to unstoppable tundra methane and other GHGs releasing deeper and deeper then joined by the ocean at increasing depths.
So a super volcanic eruption could save life if it is before the warming is greater than its cooling effect. If Yellowstone blows in 2K years, it will be far too late, but if induced or by natural reasons it goes off before circa 2050, it saves life. Soon enough, and it could save humanity as a species.

_________________
"With every decision, think seven generations ahead of the consequences of your actions" Ute rule of life.
“We do not inherit the earth from our ancestors; we borrow it from our children”― Chief Seattle
“Those Who Have the Privilege to Know Have the Duty to Act”…Albert Einstein

_________________
With friends like Guido, you will not have enemies for long.

“Intellect is invisible to the man who has none”
Arthur Schopenhauer

"The difference between genius and stupidity is that genius has its limits."
Albert Einstein

Runaway is anything that is near impossible to stop, but in this case it is the definition of 'runaway global warming'. So, according to one of your first posts, Wayne, the open ocean warming passed its tipping point in 2007, and open ocean warming accelerated tundra warming past its self release point and on to the oceans rapidly heating doing the same at depth deeper and deeper until all methane is in gaseous form or broken down to CO2 and H2O.
So excessive humans led to excessive HGHGs, which led to open ocean warming with the melting ice cap, which leads to tundra then oceans positive feedback loops. Dominoes? How about, Cascading Ecological Failure with destruction of all or most of the biosphere, and for a length of time from 50 million years to 5 billion when the Earth melts in the Red Giant phase of our star.
I hate to think it is already too late, and all my years of doing the right thing were for nothing. Same with millions of other real green people.
However, it sure looks that way.
"That 2C limit was established decades ago by an economist. In that time, more research has shown that the safe limit is closer to 1C. And, many scientists, including Dr. Kevin Anderson at the Tyndall Ctr, finds that the carbon budget has already been used up to have a good chance of remaining below 2C. These are the dirty little secrets organizations like the IPCC don't advertise. We need to end greenhouse gas emissions now, or face a very grim future.""
http://www.carbonbrief.org/blog/2014/12 ... l-warming/
Fact or Fiction?: Geoengineering Can Solve Global Warming

Neither blocking sunlight nor capturing carbon can stop climate change
http://www.scientificamerican.com/artic ... l-warming/

Climate depression is for real. Just ask a scientist
http://grist.org/climate-energy/climate ... gn=climate

_________________
"With every decision, think seven generations ahead of the consequences of your actions" Ute rule of life.
“We do not inherit the earth from our ancestors; we borrow it from our children”― Chief Seattle
“Those Who Have the Privilege to Know Have the Duty to Act”…Albert Einstein

Meeting two degree climate target means 80 per cent of world's coal is unburnable, study says

Posted on 6 February 2015 by Guest Author

This is a re-post from Roz Pidcock at Carbon Brief

"More than 80 per cent of the world's known coal reserves need to stay in the ground to avoid dangerous climate change, according to new research. Thirty per cent of known oil and 50 per cent of gas reserves are unburnable and drilling in the Arctic is out of the question if we're to stay below two degrees, the new research notes.

That vast amounts of fossil fuels must go unused if we're to keep warming in check isn't a new idea. What's novel about today's paper is that it pinpoints how much fuel is unburnable in specific regions of the world, from Canadian tar sands to the oil-rich Middle East.

Unburnable carbon

In its most recent report, the Intergovernmental Panel on Climate Change (IPCC) calculatedhow much carbon we can emit and still keep a decent chance of limiting warming to two degrees above pre-industrial levels. This is known as a carbon budget. Two degrees is theinternationally-accepted point beyond which climate change risks become unacceptably high.

As of 2010, we could release a maximum of about 1000 billion more tonnes of carbon dioxide and still have a 50:50 chance of staying below two degrees, according to the IPCC."
http://www.skepticalscience.com/meeting ... nable.html

From the previous post we know that even that is NOT enough to stop CAGW to GTE. I would say people will just not do it. Too much sacrifice from their selfishness, and too little care about the children of the future. I think not more than 1.8*C, rounded up to 2 is not going to happen and the 2 was a mistake in science. In the past a 1.5*C gain did not start a runaway, but a 5*C Arctic warming DID, both with PETM and the Permian ELE.
We just don't see it as a species, so are doomed to extinction and taking probably every species with us. The extremophobes near volcanic vents would only make it if it is 'just' a high percentage and not complete methane 'turnover'.
Both the Permian and PETM were partial turnovers, and PETM was not a true ELE(30% and not the 50% for the definition), but took 30 million years to completely heal. The heating is going up 10 times faster than PETM and is accelerating toward 40 times faster and more.
It is hard to admit that we are in a runaway right now and it will progress to assisting our population crash then eventually killing all the survivors.

I do believe that drilling mile deep holes every 4 or 5 miles around the Yellowstone magma chamber, 1/4 mile away, and at least 120 total MGT devices are simultaneously detonated is feasible to stop the process of CAGW to GTE. It would probably be a long enough winter of ten years and a ten degree F reduction in temps until the sun shines again through the settled aerosols. The population bottleneck would ensure most and our own species survival, and of course cut down the HGHGs to near zero. There is a time limit for this to work, too.
For links and more info look at the thread "the Fourth Tipping Point".

_________________
"With every decision, think seven generations ahead of the consequences of your actions" Ute rule of life.
“We do not inherit the earth from our ancestors; we borrow it from our children”― Chief Seattle
“Those Who Have the Privilege to Know Have the Duty to Act”…Albert Einstein

"The Mechanism
What is the mechanism behind accelerated warming of the Arctic Ocean, huge abrupt methane eruptions from the seafloor of the Arctic Ocean and skyrocketing temperatures?
Natalia Shakhova et al. in 2010 estimated the accumulated potential for the East Siberian Arctic Shelf (ESAS) region alone (image on the right) as follows:
- organic carbon in permafrost of about 500 Gt
- about 1000 Gt in hydrate deposits
- about 700 Gt in free gas beneath the gas hydrate stability zone.

In early 2014, Sam Carana estimated annual methane emissions from hydrates and permafrost at 100 Tg (i.e. 0.1 Gt). This methane will contribute to further warming of the air over the Arctic and the North Atlantic, causing further further extreme weather events, such as heatwaves and storms along the path of the Gulf Stream from the North Atlantic into the Arctic Ocean, in turn triggering further releases from hydrates at the seafloor of the Arctic Ocean and escalating into runaway global warming. "
http://arctic-news.blogspot.com/2015/02 ... anism.html
Yamal Peninsula
"The Yamal Peninsula stretches some seven hundred kilometres into the Arctic Ocean from the Russian mainland below the Arctic Circle. Known to it's indigenous inhabitants as 'the end of the world', this area of the Russian federation is arousing international attention.
The nomadic Nenets tribes of this peninsula have retained their traditional culture and simple way of life for over a thousand years. Surviving Stalinist Russia and the interests of the gas drilling company Gazprom they now face a new threat, climate Change and their landscape is dramatically changing. In recent years, this rich, rugged and inaccessible peninsula in Northern Siberia has been the focus of media headlines. The world's largest energy company Gazprom, is trying to fully exploit Russia's largest gas field containing an estimated half of the world’s reserves. Gazprom has embarked on an extensive venture to cash in on these gas reserves, the venture becoming Russia’s largest energy project in history. At the same time the landscape in Yamal is changing as the Arctic permafrost thaws due to warmer Arctic temperatures. Scientists are concerned that millions of tonnes of Ch4 (methane) locked in the thawing permafrost could be a ticking time bomb, a tipping point for the world's climate system."
http://www.futureworldproject.org/story/yamal
and related;
Methane Lake
"As permafrost thaws deep into the Arctic ground, history is unlocked from the ice. Even preserved young baby mammoths have been found here by Yar-Sale guide Karill Seretetto . Considered a bad omen by the Nenets marking the finder of such mamont remains to an early death, seems less superstitious once in this thawing landscape. The tundra ground that gets its stability from the permafrost has started to collapse , emptying lakes of water and creating dramatic gulleys. Most worryingly triggering the decomposition of organic residues releasing greenhouse gases such as methane into the atmosphere."
http://www.futureworldproject.org/story/methanelake

"Well, another fine mess you've got us into." (Laurel and Hardy)

_________________
"With every decision, think seven generations ahead of the consequences of your actions" Ute rule of life.
“We do not inherit the earth from our ancestors; we borrow it from our children”― Chief Seattle
“Those Who Have the Privilege to Know Have the Duty to Act”…Albert Einstein

Dingo; "The principle stands. Everything in the loop, ghgs, melting ice etc, is subject to the same diminishing dynamic of lessening feedback. That does not include anything influencing warming - for instance the repositioning of the sun in its orbit due to axial tilt generating the Malenkovich Cycles"
What you mistakenly are referring to is a negative feedback loop. The negative feedback returns to the way it was, while a positive feedback just gets bigger at an accelerating rate. So, in a way, it is a very negative thing here.
You mistake axis tilt as generating the Malenkovich Cycles. The actual cycle is from orbital variation between a rounder and a more elliptical orbit, not tilt, and it is a 100K yr. cycle. The axis tilt wobble is from 11 to 22.5* of tilt over a time span of 23K years.
For the ice age epoch to change from interglacial, the 100K M cycle has to coincide with max tip to get the albedo change needed to keep summer snows from melting, especially in the northern hemisphere.
We are presently at 22* tip and near elliptical as the orbit gets. So CAGW has completely overwhelmed the astronomical cycles.

_________________
"With every decision, think seven generations ahead of the consequences of your actions" Ute rule of life.
“We do not inherit the earth from our ancestors; we borrow it from our children”― Chief Seattle
“Those Who Have the Privilege to Know Have the Duty to Act”…Albert Einstein

So, humanity has overcome the Orbital Tilt and Wobble, and the Malenkovich Earth Orbital ellipticity.
This should be here, too, I suppose;
"Methane clathrate, also known commonly as methane hydrate, is a form of water ice that contains a large amount of methane within its crystal structure. Potentially large deposits of methane clathrate have been found under sediments on the ocean floors of the Earth"
http://en.wikipedia.org/wiki/Clathrate_gun_hypothesis
The huge Siberian methane blowholes of 2014 were Methane Clathrate Guns in its smaller effect. I used to make silver fulminate in my youth, and methane clathrate is VERY similar. Without ignition it is 100 times the heat trapping of CO2 for the first 20 years. Its stability is only with lower temperature and depth. It explosively releases with seaquakes, or as little as a 2*F temperature rise. The Siberian deposits are legendary, and 50GTs of it are ready to release, it very rapidly expands to 169 times its volume. That is just the beginning.......
Like nitroglycerin without fire. Arctic surface temperature goes +5*C or more and it starts below the surface. It is now +6*C over in the Arctic. The 50GTs of it are equivalent to 5000GTs of CO2, compared to the HGHG annual of ~33GT. Then the tundra total with all the ocean deposits is another 1000GTs, or 100K GTs of CO2, and the H2O vapor, and nitrous gases, among others. That puts the surface temperature beyond the boiling point of water. As a worst case scenario, but even an 80% turnover would would eliminate all but thermal vent life.
http://guymcpherson.com/2015/03/for-tho ... of-humans/
http://arctic-news.blogspot.com/2015/02 ... -2031.html
http://planetextinction.com/planet_exti ... hrates.htm
http://planetextinction.com/documents/M ... rvival.pdf
http://arctic-news.blogspot.co.nz/2015/ ... -2015.html
from the Clathrate Gun to Our Heads post.

_________________
"With every decision, think seven generations ahead of the consequences of your actions" Ute rule of life.
“We do not inherit the earth from our ancestors; we borrow it from our children”― Chief Seattle
“Those Who Have the Privilege to Know Have the Duty to Act”…Albert Einstein