A survey of climate scientists reveals uncertainty in their predictions of changes to the global climate, yet finds that they believe there is a real chance of passing a “tipping point” that could result in large socio-economic impacts in the next two centuries. The expert elicitation was conducted between October 2005 and April 2006 with a computer-based interactive questionnaire completed individually by participants. A total of 52 experts participated in the elicitation (see Table S2 in the PDF below for names and affiliations). The questionnaire included 7 events of crossing a tipping point. Elmar Kriegler and colleagues asked the climate experts to estimate the likelihood of impacts to components of the climate system under different warming scenarios.
The five systems discussed in the paper concerned major changes in the North Atlantic Ocean circulation, the Greenland and Western Antarctic ice sheets, the Amazon rainforest, and El Niño. The probabilities given by the experts varied widely, but on average, they assigned significant chances to a tipping point in this or the next century for at least the medium to high warming scenarios.
Using the experts’ more conservative estimates, the authors calculate a 1 in 6 chance that a tipping event will occur if the temperature increase in the next 200 years is between 2 and 4 degrees Celsius. For a higher temperature increase, the probability was just over 1 in 2. According to the authors, the results suggest that the large uncertainties that come with climate predictions do not imply low probability that catastrophic events will occur.
Since the survey was conducted in 2005 and 2006, I wonder if the opinions are equivalent today. They might have gotten more bang for their buck if they’d used a survey company like Gallup. I’m sure the results would be faster.
The paper is titled: Imprecise probability assessment of tipping points in the climate system
Elmar Kriegler, Jim W. Hall, Hermann Held, Richard Dawson, and Hans Joachim Schellnhuber,
Potsdam Institute for Climate Impact Research, PO Box 60 12 03, 14412 Potsdam, Germany; Department of Engineering and Public Policy, Carnegie Mellon
University, Pittsburgh, PA 15213-3890; School of Civil Engineering and Geosciences, Newcastle University, Newcastle-upon-Tyne NE1 7RU, United Kingdom;
Tyndall Centre for Climate Change Research, United Kingdom; and eEnvironmental Change Institute, Oxford University, Oxford OX1 3QY, United Kingdom
Edited by William C. Clark, Harvard University, Cambridge, MA, and approved February 2, 2009 (received for review September 16, 2008)
Here is their diagram of the tipping possibilities in the global climate system:
Here is the PNAS abstract
Paraphrasing: I have no idea what’s going on but it’s so scary!
“Tipping Point” is the modern name for the God of Thunder.
From a simple perusal of the polar ice-cores, the only “tipping points”, temp-wise, from an interglacial like today is down. And that from a glacial-max (like 20k yrs ago) is up.
The reason, IMO, is snow/ice albedo-feedback. Once glaciers are vastly reduced like today, any further glacial melting has little effect since they’re at high latitudes and resulting small solar insolation. At the end of interglacials, cooling eventually produces enough permanent snow/ice far enough into lower latitudes that reflected sunlight/positive feedback causes a “tipping point” toward enhanced cooling. Notice that during mid-glacial periods temps swing wildly compared to today. This is because of the presence of reflecting ice at lower latitudes providing that positive feedback — it melts & gets warmer, it grows & it gets colder.
Glacial maximums like 20k yrs ago are a bit harder to fathom — why doesn’t the glacial advance continue unabated? My guess is that further ice formation toward the equator is halted by poleward moving tropical ocean-currents, lack of glacier-prone land-areas, etc.
Then there is the recovery from glacial maximums (which are very fast geologically). This is even harder to fathom. Perhaps some long-term negative-feedback operating in ocean currents? I don’t know. One thing that’s apparent is that some “trigger” seems to operate, like maximum summer sun in the northern hemisphere 15k-12k yrs ago that produced warmer temps there & pushed a tipping point toward rapid glacial melting.
Just my ideas.
“Pierre Gosselin (01:01:14) :
LA NINA
Speaking of tipping, looks like we may be tipping into yet another La Nina. There’s some awfully cold water pooling out there.”
http://www.osdpd.noaa.gov/PSB/EPS/SST/climo&hot.html
On that same web page, further down, there is are a couple maps of “coral bleaching hotspots”. Is it my imagination, or are the hotspots only showing up in places where no one ever goes?
Mike
There is a tipping pointfor your patience too, I guess. You as americans, living in the most important country, are at the focus of this warming, cooling, or whatever climate conspiracy, and you are the first ones to be burnt under the magnifying glass of some unknown NGO composed of allucinated people which sword themselves as the ones being the sheperds of the human flock and who seek to apply on you what they are sure is for your benefit and well being.
He who knows not and knows not that he knows not is a fool; avoid him.
He who knows not and knows that he knows not is a student; teach him.
He who knows and knows not that he knows is asleep; wake him.
He who knows and knows that he knows is a wise man; follow him.
Hmmmm who fits in each spot? I guess I’m in the second spot…
Pierre, that is precisely why I posted what I did. I understand the satire myself, but after reading some other posts it became apparent that some others perhaps did not. I think what is a bit misleading (and it grabbed me initially) is the caption to the image “Thanks to the Environmental Protection Act – tipping is illegal in the UK”. At least here in the US, the first thing one is opt to think of, is tipping your waiter/waitress in a restaurant or bar. And, I usually don’t think very highly of the EPA in our country, however, this particular law in the UK makes a lot of sense to me. It should be illegal to dump trash wherever you want, as it is here in the US, although you probably can’t tell in most places.
“”” anna v (21:36:03) :
continuing my anna v (21:19:00) :
Back of the envelope:
Since as far as the sun goes, the earth and moon are in the same ballpark, if all the sun energy falling on the moon at full moon came to earth, that would give 5% extra energy ( radius of moon 1/8 of earth, area of face pi*r**2). Thats a lot of watts per meter square. average would be half of that. “””
The operational words in this Anna, are “IF ALL” ; and if it did that would be simply “off all”, wouldn’t it.
Fortunately that doesn’t happen. The sun may be illuminating the moon (and earth) with a nearly colimated beam having about a half degree divergence; but in addition to a less than one reflection coefficient; the moon’s surface is a highly diffuse reflector, so one can reasonably presume that the moon is a Lambertian reflector.
I think your back of envelope may have some typos, because if the moon is only 1/8th of earth’s diameter (that sounds too small) the areas would be 1/64th, which doesn’t get you any 5%. But if that was a good ratio, then the earth would subtend about 4 degrees.
Google says moon is 1/4 earth; 3475 km versus 12742 km.
So areas are 1/16, which would be 6 1/4%.
But now earth subtends 2 degrees at moon or 1 degree semi-cone angle.
So flux from Lambertian source would be pi x I x sin^2(1deg) , or since total flux is pi x I then the fraction is simply sin^2(1 degree) n= 3 x 10^-4
So even a perfectly reflecting moon would only add 0.03% to earth’s solar energy, at full moon.
Actually it is more likely that the moon’s surface reflectance is closer to isotropic than Lambertian, in which case it would be even less.
George
I have no earthly idea where that > n < came from after the sin^2 term, so if Anthony or ops can’t expunge that; I’ll just claim that it needs to be there as the refractive index of space, which is 1, so just forget that n ; and in any case if it was the refractive index, it would have to be in there as n^2, so pray for rain to wash that n away.
George
“”” But as to the earth’s climate having tipping points; given that the orbital parameters stay pretty much what they now are. No system that is as stable as the earth’s climate is, could possibly have tipping points, or it would have tipped a long time ago.
So forget climate tipping points; that’s also a scam; just like tipping is.
George, I’m not so sure. I think we DO have tipping points, in a nice Hysteresis system of ice ages. “””
Say E.M. IANAL but I tend to write like one.
See where I said; “given that the orbital parameters stay pretty much what they now are. ”
Now I deliberately put that in there for the express purpose of eliminating your ice ages hysteresis, which most people seem to agree happen when the orbital parameters change to something different from what we have now.
Yes I agree that ice ages occur and are sort of regenerative; so I eliminated that case.
OK; you have to read what I say; not what you thought I said.
And yes Kiwiland still frowns on tipping and for the same reasons.
Tena koe
Mike Bryant, excellent post. I’m for the second line , also. There are 3 types of people in the world, those that are good at math, and those that aren’t.
I’m intrigued by the electric Sun hypothesis. Apparently, the toroidal ring current surrounding the sun has disappeared or is experiencing less current density and has de-energized below our ability to detect. This makes sense if there is a drop in the current which is directed into the sun via the toroidal ring current.
So basically the Sun acts like a condensor and the Earth acts as a ‘leaky’ capacitor (the components being the ionosphere, atmospheric moisture and the ground/crust) with the magma acting as a resistor. The magma is actually a dense, pressurized plasma, so the ‘drift’ current induces heating due to random electron collissions. The current also induces a magnetic field and rotation due to a homo-polar motor effect. The mass of the Earth acts like a flywheel, moderating any changes in rotational velocity due to fluctuations in the current.
If this hypothesis is actually true, then climate extremes would be limited to the amount of current received from the Sun. It would also be more likely to reach the maximum limit more frequently than the minimum limit. The only ‘tipping’ point would be a sudden surge in the current powering the Sun. Then we’d have devastating CME’s to worry about (exploding plasma ‘double layers’, more so than any changes to climate.
Anyway, I like to think outside the ‘sphere’. And besides, climate in that model is inherently controlled by total energy received from the Sun, like a heating element.
I could be wrong, but empirical data, especially certain details, matches the model, imo.
On that same web page, further down, there is are a couple maps of “coral bleaching hotspots”. Is it my imagination, or are the hotspots only showing up in places where no one ever goes?
Mike
They correlate far better to the SSTs right above them than to the lack of human visitation. 😉
solrey (10:28:16) :
I’m intrigued by the electric Sun hypothesis. Apparently, the toroidal ring current surrounding the sun has disappeared
[…]
Anyway, I like to think outside the ’sphere’.
I think you are far, far outside. The electric Sun hypothesis is not even wrong, but does have a certain entertainment value.
“”” solrey (10:28:16) :
I’m intrigued by the electric Sun hypothesis. “””
You need to call George Noory of Coast to Coast AM; he’d love to talk to you about your hypothesis. He needs a change from Michio Kaku and some of his other regulars.
George
George E. Smith (08:54:41) :
George note I was saying radius not diameter for 1/8th, but I did forget that in these units the earth area would be 3.14, so instead of 5% it is 1.6% of the energy falling on earth.
I am willing to forget that n. You are treating the moon as a diffuse source, I am thinking of it as a total reflector ( if aluminized) that would just keep the parallelism of rays coming from the sun, we should see an image of the sun. I am trying to think whether the cone is relevant in this case. It would not be for coherent radiation, and parallel rays seem similar to coherent to me, but you may be right. If so, one could put large parabolic mirrors to transfer the energy , but that would be much more expensive.
There are tipping points in nature, but there are also tipping points in politics
–Al Gore
http://www.guardian.co.uk/world/2009/mar/14/al-gore-climate-change1
Mike Bryant:
“On that same web page, further down, there is are a couple maps of “coral bleaching hotspots”. Is it my imagination, or are the hotspots only showing up in places where no one ever goes?”
To Mike and all the WUWT crew: THAT IS A BIG LIE Along the central west coast of south america THERE ARE NO corals whatsoever, as you may guess, because of the cold Humbolt current. Islands are absolutely deprived of anything other than sea birds’ dung (“Guano”, pronouced “Gooahno”, after the quecha for dung)
If real those yellows and oranges are more probably related to undersea hot spots along the Nazca tectonic plate.
Re: coral bleaching hotspots
They are simply showing areas where the temps are high enough to promote coral bleaching. It is the exact same information as the SST graphic, but the color scale is shifted. Obviously the huge warm areas of the open, deep Pacific are probably not seeing much coral bleaching either. The graph has nothing to do with whether or not coral bleaching is being observed in any particular location.
Ian (18:41:07) :
Robert Austin “The fabulous tipping point, Hansen’s deus ex machina”.
What a fabulously clever statement! Mind if I borrow it sometime? 🙂 Yes it totally is his deus ex machina, LOL … totally.
Thanks for your appreciation, ian. I would be flattered if others were to borrow my bon mot and extend its reach.
“Purakanui (01:18:49) :
Tena koe anna v
On geothermal energy: Did you know that there exist applications for heating and cooling houses with it?”
I understand Icelanders do something similar too. But there is an issue, Geothermal sources do change. From memory, there are Geothermal installations in Iceland that are abandoned (Or were).
“In New Zealand we obtain a small but growing part of our electrical energy from geothermal steam and are currently adding further power stations, mainly in the Volcanic Plateau of the central North Island. Many homes and hotels in Rotorua use the steam directly for home heating and many motels offer private thermal spas along with the room. In Rotorua, they had to slow down the use because the famous geysers at Whakarewarewa were being depleted as pressure reduced.”
Indeed it was. But the reduction in this use lead to another “problem” as I recall. Hot springs and mud pools were popping up all over town in Rotorua (Refered to Rotovegas on some Wellington radio shows), in fact some people were hurt or killed.
Rotorua has the very famous “Champagne Lake”, spectaular, complete with CO2 bubbling up from the depths.
Then there is Taupo with it’s hot springs too. Truely awsome place.
David Ball, I am not sure which post you are referring to that I was mean spirited in. Regarding climate, I have posted my opinion about climate many times on this blog. Think back to your 5th grade science textbook: Temperate Forest, Desert, etc. These are all explained and their climates outlined. Unless the address changes for these ecosystems, the typical climate for each will pretty much stay the same within a range of weather pattern variations. Climate is easy to predict, weather, not so much.
My above comment on “tipping point” is that it is likely used in order to get a submission to rise to the top of grant applications, or get an article published. My parody was related to that phrase.
OT. but under those sea Hot Spots:
Carved columns in a “sunken city” of the Chavin culture , 6.000 feet under sea water.
http://www.giurfa.com/chavinsunken.jpg
Chavin culture
http://en.wikipedia.org/wiki/Chav%C3%ADn_culture
@hotrod (22:10:51) :
I think perhaps you’ve got it… The liquid water, vapor, ice limits. I’d only add that we are almost at the CO2 ice formation temperature at the south pole now. I have to imagine that at some point in the formation of an ice age it would be colder and we might well be sucking out CO2 along with water. If the plants had a CO2 starvation die back we’d be set for a reversal (and then perhaps the clathrates in the ocean bottom depressurize and start to bubble) we could get the “kicker” that started back toward the ice melt (more CO2, more water vapor, etc. ) phase.
Basically I think that vegetation may well play a part and that part may interact with volcanic gasses and clathrate sequestration in the ocean bottoms.
I wish I could recall the source but during the time period that the “snow blitz” theory was popular, some scientist built a model where the earth was covered with a single vegetation type that had white flowers and dark flowers when it bloomed.
By changing the proportion of the two varieties, their impact on his albedo numbers were sufficient according to him, to trigger or terminate ice ages. For example if the dark flower variety liked cold weather, it would dominate when ice cover was maximum, (like pine forest) and if the white flower variety liked warm weather it would dominate during interglacial periods and push us back toward a cooler climate.
I think the biggest problem is everyone is looking for “THE smoking gun”. I suspect we have lots of smoking “cap guns” that when combined are enough to do the job.
What if we have 10 effects that tend to limit warming at some max temp and 10 effects that limit cooling at max ice cover, and each are about of equal impact?
In that case, no one of them contributes more than 10% of the total necessary negative feedback to put a hard limit on either excursion. You don’t necessarily need to find the driver, you may in fact be looking for a team of drivers each of which is insignificant by themselves.
One other thought on this topic, came to me as well last night.
In my view, the weakest side of my theory is the cold recovery to warming trigger limiting factors. I got to thinking last night, that at max ice coverage, we also have lots and lots of continental shelf that is exposed and it has 100,000 years to be covered by mature dense forests and grass lands that tolerate cold climates. In solar energy research studies, they found that there was hardly any practical difference between the thermal efficiency of a solar collector painted dark green vs one painted flat black. Dark green is a very acceptable color to absorb solar energy.
The cold limit could be a combination of new exposed land area due to dropping sea levels, which during the summer time gets quite warm without near by bodies of water to moderate the temperature. High dust levels (already demonstrated during cold periods) to “dirty” the ice in the summer. The remaining low humidities implied by the high dust content, make convective thunderstorms almost impossible due to both low humidity and over seeding air masses (think dust bowl). That drastically cuts albedo reductions due to thunder storm and hurricane cloud decks, and the heat transfer due to convective pumping of heat into the upper troposphere through that mechanism.
Add one or two other minor effects and you might have sufficient negative feed back to turn it around after 100K years.
Side note — one of the most efficient thermal conductors known to science is the heat pipe. A heat pipe is a tube containing a fluid which can evaporate, held at low pressure so the fluid is near its boiling point. When the hot end of the heat pipe is exposed to heat, the fluid flash boils and rushes to the cold end of the heat pipe where it condenses out, giving up its latent heat as it changes back to a liquid.
It then is transported back to the cold end of the tube by capillary action in the wick lining the inside of the tube.
A convective thunderstorm is, for all intents and purposes, a gigantic heat pipe. It takes heat captured and stored in low level water vapor, which when atmospheric instability reaches a critical value it “turns on” and explodes into rapid heat driven convection, pushing millions of tons of water vapor to high altitude where it freezes out as ice crystals over a very short time period, releasing its stored latent heat to the upper layer of the troposphere. Strong storms even push up past the troposphere into the lower levels of the stratosphere in over shooting tops, where that heat can easily be radiated to space at altitudes of 60,000+ft. Then that water is recycled back to the ground as rain, snow, or hail, (like the wick return path in the heat pipe) to be reused the next day to store and move heat again.
If you think of the total latent heat of water liberated at high altitude, from a storm that is capable of dropping 2 inches to 20 inches of water content over a hundred square miles in a single evening. The combined heat pumping potential of the worlds thunder storms is mind boggling. All you need to verify that is the cool SST path that follows a large hurricane as it cools the ocean surface by both shading and pumping heat to the upper atmosphere. SST drops from a single storm can be on the order of 4 deg C, over its storm track.
http://ams.allenpress.com/perlserv/?request=get-document&doi=10.1175%2F1520-0493(1997)125%3C2716%3ASIOSST%3E2.0.CO%3B2
Larry
anna v (21:19:00) : I have been thinking of aluminizing the moon: i.e. cover the face facing us with aluminum foil 🙂
Interesting idea. I think it would be more effective to keep the aluminum as sheets in near geosync orbit so you could get more direct reflection onto the planet… much less mass to lift.
Somewhere I saw a report of a geologist who’d figured out that ice ages can only form with our present ocean current pattern and that they did not form prior to Panama rising… and speculated that atomic blasting a very big trench where Panama is would restore a non-iceage pattern. I suppose the folks in Panama would object 😎 And depending on the effect on the Gulf Stream some parts of Europe might not be too happy…
Personally, I’d go for a soot layer on the marginal ice to try to prevent multiyear ice forming. We can make lots of soot… It would also be a good time to test the super-greenhouse gasses theory. Another interesting if hair brained idea would be to make nuclear power plants mounted on skids that used the glacier as the cooling system. The EPA report might be a bit hard to sell 😉
Then again, maybe all we would need to do is swap all the cows, pigs and chickens from corn meal to beans ;-‘) Gee, this is much more fun than all that AGW doom and gloom!
And finally, since a stable polar ice cap at the N. Pole is required, we could investigate nuclear dredging of the Bering approach (or wherever it turns out that the sub-polar water flow is restricted). Heck, if it took 3 or 4 nukes a year to keep the Arctic ocean flowing, we’d not run out for 1000 years just with our present inventory (and I’m sure we could come up with something even better in 1000 years…) and we’ve got an existence proof that 3 or 4 nukes a year can be set off without destroying the planet (though Alaska and Siberia might complain a bit… but considering the alternative… )
You know, I could really get into this fantasy! To quote Marvin the Martian “Where’s the KABOOM! There’s supposed to be an earth shattering KABOOM!” 8-}
(Here’s where somebody with lots of physics background is supposed to chime in with a really trick way to change the polar tilt such that we don’t have the right obliquity for an ice age by making our gyroscope stumble just a tiny bit just so with a well place mass anomaly or something cool…)