In the Press: Joe Bastardi: Obama Prostituting Climate Science

[Sundog]

I won't pretend to know how a private sector company like WB works, however I know an agenda when I see one. Much like anyone else I suppose JB knows who is paying him. A few big corporate clients that want to hear AGW is rubbish, would make up for a lot of small frys that subscribe.

JB would have us believe that Al Gore and every other AGW proponent is in it for the money, however the money to be made is a pittance when compared with what the fossil fuel guys bring in.

 

Yea I never understood this nonsense argument. All scientists are conspiring to get what? Grants? Lol. If they went so far out of the way to "pretend" global warming is real to get money then these people are the worst investors of all time. Fossil fuels dwarf every other industry on the planet. 

[WeatherRusty]

My questions about this fact are as follows:

1. Were there not periods of much higher atmospheric CO2 centuries ago?

2. What proven effects, if any, did CO2 have at these times and on what timescale were the effects notable?

3. The earth/atmosphere is how old compared to the 120 or so years we consider to be studied/modified/re-studied and re-modified x number of times?

Thanks in advance.

 

1)  No there were not. Millions of years ago CO2 consentration was much higher. During the ice age cycles covering the past 3 million years CO2 has varied mostly between 180ppm and 280ppm.

 

2) Prior to about 32 million years ago and through the Cretaceous Period Earth was in a hot house climate many degree C warmer than today. No permanent ice sheets existed. The continents were in somewhat different positions and CO2 concentration exceed 500ppm. Also there are known shorter periods where temperatures spiked strongly ie. (PETM), where carbon incursions are noted in the geologic strata dated concurently.

 

3) AGW theory is founded independently of the temperature reconstructions. It is grounded in physics and explains the warming pattern over the past century whereas natural variability can not. The age of the Earth has nothing to do with it. Global climate change is forced according to many factors including, long and short term changes in solar output, geology, sedimentation rate, volcanism, plate techtonics, and the composition of the atmosphere. We are currently and significantly altering the composition of the atmosphere and oceans.

 

AGW is a boundary change problem. It's the marginal difference in CO2 which matters to the temperature of the near surface of the Earth. By doulbing CO2 concentration the lower atmosphere radiates infrared less efficiently to space by 3.7W/m^2, much the same as how putting on cloths or a blanket warms the air surrounding your body by slowing the loss of heat energy. Additional energy is not required to warm the surface. A body which looses energy more slowly will become a warmer body. In the case of a doubling of CO2, the near Earth surface eventurally becomes 1.2C warmer before the consideration of any feedback mechanisms.

[56er]

I won't pretend to know how a private sector company like WB works, however I know an agenda when I see one. Much like anyone else I suppose JB knows who is paying him. A few big corporate clients that want to hear AGW is rubbish, would make up for a lot of small frys that subscribe.

JB would have us believe that Al Gore and every other AGW proponent is in it for the money, however the money to be made is a pittance when compared with what the fossil fuel guys bring in.

What would be the purpose of fossil fuel guys buying off JB? What big corporate clients would want to hear that AGW is rubbish? That doesn't make any sense at all.

[FloridaJohn]

What would be the purpose of fossil fuel guys buying off JB? What big corporate clients would want to hear that AGW is rubbish? That doesn't make any sense at all.

Sure it does. It is the same strategy the tobacco companies used to delay laws coming into effect that negatively hurt their business. The tobacco companies held off those laws for 50 years. The fossil fuel companies are on track to delay any legislation even longer.

 

The purpose of anti-AGW rhetoric is to confuse the general public. If a case can be made that the scientists are not in agreement, then fossil fuel companies can point to this "lack of consensus" as a reason to not change anything. As long as the public is confused as to what is actually known, nothing will change. This is why corporate clients would want to hear that AGW is rubbish.

[wildweatherman179]

1) No there were not. Millions of years ago CO2 consentration was much higher. During the ice age cycles covering the past 3 million years CO2 has varied mostly between 180ppm and 280ppm.

2) Prior to about 32 million years ago and through the Cretaceous Period Earth was in a hot house climate many degree C warmer than today. No permanent ice sheets existed. The continents were in somewhat different positions and CO2 concentration exceed 500ppm. Also there are known shorter periods where temperatures spiked strongly ie. (PETM), where carbon incursions are noted in the geologic strata dated concurently.

3) AGW theory is founded independently of the temperature reconstructions. It is grounded in physics and explains the warming pattern over the past century whereas natural variability can not. The age of the Earth has nothing to do with it. Global climate change is forced according to many factors including, long and short term changes in solar output, geology, sedimentation rate, volcanism, plate techtonics, and the composition of the atmosphere. We are currently and significantly altering the composition of the atmosphere and oceans.

AGW is a boundary change problem. It's the marginal difference in CO2 which matters to the temperature of the near surface of the Earth. By doulbing CO2 concentration the lower atmosphere radiates infrared less efficiently to space by 3.7W/m^2, much the same as how putting on cloths or a blanket warms the air surrounding your body by slowing the loss of heat energy. Additional energy is not required to warm the surface. A body which looses energy more slowly will become a warmer body. In the case of a doubling of CO2, the near Earth surface eventurally becomes 1.2C warmer before the consideration of any feedback mechanisms.

I understand the formula used there. Have seen it used many times. I disagree with the statement that the age of earth has nothing to do with it. I was sort of asking an ignorant sounding question there but the point being that the earth is much older than the climate record obviously. At 120 years, 64 years, or whatever time scale you take, you're talking about a very small mark even compared to 1000 years. Also, I'm very aware of the ppm rises in co2 measured since 1950. It is no doubt a very linear rise, almost predictably so. The question associated with this statement is, "Where is the linear rise in effect?" If you cannot use temperatures due to climate change being independent of them, what can you use? Individual weather events, long term patterns, radiative forcing, sea ice? This is usually the point where I get lost in all this. Maybe you could shed some light on it.

[Quixotic1]

Yea I never understood this nonsense argument. All scientists are conspiring to get what? Grants? Lol. If they went so far out of the way to "pretend" global warming is real to get money then these people are the worst investors of all time. Fossil fuels dwarf every other industry on the planet.

  

Rule 1 in a disinformation campaign is to accuse the other side of what you are guilty of.

Sure it does. It is the same strategy the tobacco companies used to delay laws coming into effect that negatively hurt their business. The tobacco companies held off those laws for 50 years. The fossil fuel companies are on track to delay any legislation even longer.

 

The purpose of anti-AGW rhetoric is to confuse the general public. If a case can be made that the scientists are not in agreement, then fossil fuel companies can point to this "lack of consensus" as a reason to not change anything. As long as the public is confused as to what is actually known, nothing will change. This is why corporate clients would want to hear that AGW is rubbish.

Indeed. A racuous 3% drowns out the other 97.

[56er]

Sure it does. It is the same strategy the tobacco companies used to delay laws coming into effect that negatively hurt their business. The tobacco companies held off those laws for 50 years. The fossil fuel companies are on track to delay any legislation even longer.

 

The purpose of anti-AGW rhetoric is to confuse the general public. If a case can be made that the scientists are not in agreement, then fossil fuel companies can point to this "lack of consensus" as a reason to not change anything. As long as the public is confused as to what is actually known, nothing will change. This is why corporate clients would want to hear that AGW is rubbish.

Yeah but who is JB? Ask 1000 people on the street and 975 of them probably never heard of the guy! I just don't see buying off JB as making any sense. You say corporate clients want to hear it. Do you mean they want the public to hear it? Is that why Al Gore pushes so hard in the opposite direction? Who are his corporate clients? Or is he just an honest ex-politician with everyone's best interest in mind?

[The_Global_Warmer]

Yeah but who is JB? Ask 1000 people on the street and 975 of them probably never heard of the guy! I just don't see buying off JB as making any sense. You say corporate clients want to hear it. Do you mean they want the public to hear it? Is that why Al Gore pushes so hard in the opposite direction? Who are his corporate clients? Or is he just an honest ex-politician with everyone's best interest in mind?

 

 

I don't know anything about corporate clients paying Gore to be an advocate.  But his passion for it started in the 1960s well before he could have ever had corporate clients.

 

Harvard

Gore enrolled in Harvard College in 1965, initially planning to major in English and write novels, but later deciding to major in government.^[21][22] On his second day on campus, he began campaigning for the freshman student government council, and was elected its president.^[22]

Although he was an avid reader who fell in love with scientific and mathematical theories,^[22] he did not do well in science classes in college, and avoided taking math.^[21] His grades during his first two years put him in the lower one-fifth of the class. During his sophomore year, he reportedly spent much of his time watching television, shooting pool, and occasionally smoking marijuana.^[21][22] In his junior and senior years, he became more involved with his studies, earning As and Bs.^[21]In his senior year, he took a class with oceanographer and global warming theorist Roger Revelle, who sparked Gore's interest in global warming and other environmental issues.^[22][29] Gore earned an A on his thesis, "The Impact of Television on the Conduct of the Presidency, 1947-1969", and graduated with an A.B. cum laude in June 1969.^[21][30]

 

 

 

[FloridaJohn]

Yeah but who is JB? Ask 1000 people on the street and 975 of them probably never heard of the guy! I just don't see buying off JB as making any sense. You say corporate clients want to hear it. Do you mean they want the public to hear it? Is that why Al Gore pushes so hard in the opposite direction? Who are his corporate clients? Or is he just an honest ex-politician with everyone's best interest in mind?

 

The anti-AGW crowd is always looking for a new advocate. Perhaps JB will start making the rounds on Fox News, et al to talk about how the "science isn't settled" and how there is "still much disagreement among scientists." He has some generic weather "cred," so that can be twisted into turning him into an "expert" for TV or news report reasons. Most of the public hasn't heard of any of the climate scientists before, so they are all interchangible. The fossil fuel companies just need someone "on their side."

 

And yes, the corporate clients want the public to hear his opinions, that is the purpose of funding him. This is the same reason private corporations fund "think tanks," so that they can get their message out to the public from an "independant" source.

 

Al Gore may have corporate clients that want the public to hear his message, but if he does, they are significantly underfunded compared to the fossil fuel industry. There really is no comparison to any other interests and the fossil fuel interests. My guess is that Al Gore has a genuine interest in getting out the truth about AGW, but is not opposed to making a buck if it aligns with those interests. Al Gore's main marketing point is that he has "brand" recognition.

[LocoAko]

The anti-AGW crowd is always looking for a new advocate. Perhaps JB will start making the rounds on Fox News, et al to talk about how the "science isn't settled" and how there is "still much disagreement among scientists." He has some generic weather "cred," so that can be twisted into turning him into an "expert" for TV or news report reasons. 

 

Too late for that...

 

 

 

[FloridaJohn]

Too late for that...

 

LOL. I really had no idea he has already been on Fox News when I wrote that.

[The_Global_Warmer]

lol oh my god.

 

Yeah we are well on our way to returning to the 1970s!!!

[Snow_Miser]

Incredible that he thinks that the first law of thermodynamics contradicts the greenhouse effect in that first video you posted Jake. Shows a complete lack of understanding in how the greenhouse effect actually works.

[WeatherRusty]

I understand the formula used there. Have seen it used many times. I disagree with the statement that the age of earth has nothing to do with it. I was sort of asking an ignorant sounding question there but the point being that the earth is much older than the climate record obviously. At 120 years, 64 years, or whatever time scale you take, you're talking about a very small mark even compared to 1000 years. Also, I'm very aware of the ppm rises in co2 measured since 1950. It is no doubt a very linear rise, almost predictably so. The question associated with this statement is, "Where is the linear rise in effect?" If you cannot use temperatures due to climate change being independent of them, what can you use? Individual weather events, long term patterns, radiative forcing, sea ice? This is usually the point where I get lost in all this. Maybe you could shed some light on it.

 

While CO2 forcing has been quit linear, it is obvious that the Earth's lower atmospheric short term temperature trend does not march in lock step with it. The simple answer as to why is that CO2 is not the only factor governing lower atmospheric temperature on a relatively short term basis.

 

Climate change is like a tug of war between competing forces. The climate today is a consequence of what is termed a dynamic equilibrium. Constantly changing parameters net out at a moving equalibrium point. The combined effect of all human caused forcing is estimated to be about +1.6 watts per meter squared. This accounts for all the long lived greenhouse gases such as CO2 and CH4. The negative forcing from aerosol pollution, the positive of black carbon and so on. We have solar variability, ENSO and other effects imparting both negative and positive forcing. The real world temperature response will never follow a linear pattern.

 

However, all the natural forcing is quit stable over the longer term (say 30 years to a century) or the forcing from any one is relatively weak. For instance, solar output would have to increase by 22W to impose the same radiative forcing given from a doubling of CO2 (3.7W/m^2). The positive and negative phases of natural cycles tend to average out to near zero given time. The one thing which humans are affecting is the baseline greenhouse effect and it's associated forcing.

 

To answer your question directly, the science looks to determine the net radiative forcing at the boundary between Earth's atmosphere and space. They consistantly find a positive value where more energy is entering the system than is leaving. The value is small, less than 1W/m^2, but it has been consistantly positive. This means the near surface of the Earth is accumulating energy which will eventually have to manifest as sensible heat.

[Msalgado]

I only watched a part of the first video but saying the greenhouse effect violates the 1st law shows that the guy is either lying through is teeth or has an incredibly poor understanding of atmospheric physics.  

[nflwxman]

I only watched a part of the first video but saying the greenhouse effect violates the 1st law shows that the guy is either lying through is teeth or has an incredibly poor understanding of atmospheric physics.  

JB is lying.  I refuse to believe someone that well educated on the physics of weather is ignorant to that very principle of atmospheric chemistry.

 

I mean, even Roy Spencer and company acknowledge the 1.2C warming with a doubling of CO2.  The feedbacks is where they differ.

[WeatherRusty]

I only watched a part of the first video but saying the greenhouse effect violates the 1st law shows that the guy is either lying through is teeth or has an incredibly poor understanding of atmospheric physics.  

 

It is giving JB the benefit of the doubt to say he is lying. A simple illustration serves to demonstrate the greenhouse effect to be in perfect keeping with the 1st law. Insolation penetrates the atmosphere to the surface where it is absorbed by the land and oceans to depth. The land to just a few inches or feet. The oceans to hundreds of feet. This raises the temperature of the surface until the radiation emitted from the surfaces equals the incoming solar radiation.

 

What happens if we slow the loss of energy emitted from the surface to the upper atmosphere with the introduction of atmospheric componets which absorb some of that energy? The established equalibrium between radiation and surface temperature is disturbed. Solar energy entering the system remains the same while the energy leaving the near surface is reduced. The near surface must increase it's temperature in order to again establish radiative equalibrium. The land and oceans to depth are warmed more so than before. The lower atmosphere is warmed by the warmer surface. Because the lower atmophere and surface has warmed, the upper atmosphere must cool since the total energy entering and exiting the system must remain unchanged. The same total energy has been compressed to a level closer to the surface. The 1st law has not been violated.

 

No additional energy has entered the system. The same energy value is exiting the system as before.

[The_Global_Warmer]

It is giving JB the benefit of the doubt to say he is lying. A simple illustration serves to demonstrate the greenhouse effect to be in perfect keeping with the 1st law. Insolation penetrates the atmosphere to the surface where it is absorbed by the land and oceans to depth. The land to just a few inches or feet. The oceans to hundreds of feet. This raises the temperature of the surface until the radiation emitted from the surfaces equals the incoming solar radiation.

 

What happens if we slow the loss of energy emitted from the surface to the upper atmosphere with the introduction of atmospheric componets which absorb some of that energy? The established equalibrium between radiation and surface temperature is disturbed. Solar energy entering the system remains the same while the energy leaving the near surface is reduced. The near surface must increase it's temperature in order to again establish radiative equalibrium. The land and oceans to depth are warmed more so than before. The lower atmosphere is warmed by the warmer surface. Because the lower atmophere and surface has warmed, the upper atmosphere must cool since the total energy entering and exiting the system must remain unchanged. The same total energy has been compressed to a level closer to the surface. The 1st law has not been violated.

 

No additional energy has entered the system. The same energy value is exiting the system as before.

 

He is lying.

 

There is no way he doesn't understand this.

 

He doesn't exhibit some of the most classic tell tale signs because he isn't conflicted.  He is completely bought into his act and doesn't care.  Most people lie out of necessity while still feeling guilt, remorse, regret from being ethically or morally compromised because of the act or events surrounding the act. 

 

Bastardi has zero remorse for being full of shyt. So he comes across believing 100% in what he is presenting.  This inherently makes him physically appear comfertable and completely genuine to folks who are ignorant of what he is saying or susceptible to his words stemming from their own personal beliefs where they are able to discard irrefutable evidence to the contrary.

 

 

On this forum at least.  Literally no one is going to argue on JBs behalf and back what he says in the top video.

 

So JB most preys on the woefully ignorant.

[NEOH]

He is lying.

 

There is no way he doesn't understand this.

 

He doesn't exhibit some of the most classic tell tale signs because he isn't conflicted.  He is completely bought into his act and doesn't care.  Most people lie out of necessity while still feeling guilt, remorse, regret from being ethically or morally compromised because of the act or events surrounding the act. 

 

Bastardi has zero remorse for being full of shyt. So he comes across believing 100% in what he is presenting.  This inherently makes him physically appear comfertable and completely genuine to folks who are ignorant of what he is saying or susceptible to his words stemming from their own personal beliefs where they are able to discard irrefutable evidence to the contrary.

 

 

On this forum at least.  Literally no one is going to argue on JBs behalf and back what he says in the top video.

 

So JB most preys on the woefully ignorant.

Pot meet kettle.

[StudentOfClimatology]

While CO2 forcing has been quit linear, it is obvious that the Earth's lower atmospheric short term temperature trend does not march in lock step with it. The simple answer as to why is that CO2 is not the only factor governing lower atmospheric temperature on a relatively short term basis.

Climate change is like a tug of war between competing forces. The climate today is a consequence of what is termed a dynamic equilibrium. Constantly changing parameters net out at a moving equalibrium point. The combined effect of all human caused forcing is estimated to be about +1.6 watts per meter squared. This accounts for all the long lived greenhouse gases such as CO2 and CH4. The negative forcing from aerosol pollution, the positive of black carbon and so on. We have solar variability, ENSO and other effects imparting both negative and positive forcing. The real world temperature response will never follow a linear pattern.

Bingo. Neither ECS or TCR is constant, yet pseudo-skeptics, deniers, and good scientists alike are constantly looking for a steady, unchanging value despite plentiful paleoclimatological evidence. Even feedbacks themselves are highly non linear over longer periods of time. I gravitate towards a climate sensitivity of 3.5-4.5C per doubling of CO2, based on ice core data during the latter stages of the last 4 interstadials, which are quite analogous in nature. I have based that figure is based in present time and suspect it will change along with systematic internal harmonics.

However, all the natural forcing is quit stable over the longer term (say 30 years to a century) or the forcing from any one is relatively weak. For instance, solar output would have to increase by 22W to impose the same radiative forcing given from a doubling of CO2 (3.7W/m^2). The positive and negative phases of natural cycles tend to average out to near zero given time. The one thing which humans are affecting is the baseline greenhouse effect and it's associated forcing.

This is sketchy, as it depends on what you want to call a "forcing". The well documented, long term global temperature swings throughout the Holocene interstadial (some in excess of 1.5C globally) are a product of circulation changes alone. The ENSO cycle is a shorter term example of this phenomenon working on a higher frequency, however, similar harmonics operating on lower frequencies can be easily noted in the paleoclimate data, on resolutions spanning 100yrs to 1500yrs. This suggests a climate system that is highly sensitive to radiative forcing of any kind, and highly dynamic in how it goes about reaching equilibrium.

You can't simplify the climate system down to S-B derived fluxes because the Earth system is not a static domain, internally. Only a fraction of the energy budget is in dynamic interplay at a given interval, and that value will change over time due to changes in winds and convective regimens, as we see with ENSO on the shorter term.

[WeatherRusty]

Bingo. Neither ECS or TCR is constant, yet pseudo-skeptics, deniers, and good scientists alike are constantly looking for a steady, unchanging value despite plentiful paleoclimatological evidence. Even feedbacks themselves are highly non linear over longer periods of time. I gravitate towards a climate sensitivity of 3.5-4.5C per doubling of CO2, based on ice core data during the latter stages of the last 4 interstadials, which are quite analogous in nature. I have based that figure is based in present time and suspect it will change along with systematic internal harmonics.

This is sketchy, as it depends on what you want to call a "forcing". The well documented, long term global temperature swings throughout the Holocene interstadial (some in excess of 1.5C globally) are a product of circulation changes alone. The ENSO cycle is a shorter term example of this phenomenon working on a higher frequency, however, similar harmonics operating on lower frequencies can be easily noted in the paleoclimate data, on resolutions spanning 100yrs to 1500yrs. This suggests a climate system that is highly sensitive to radiative forcing of any kind, and highly dynamic in how it goes about reaching equilibrium.

You can't simplify the climate system down to S-B derived fluxes because the Earth system is not a static domain, internally. Only a fraction of the energy budget is in dynamic interplay at a given interval, and that value will change over time due to changes in winds and convective regimens, as we see with ENSO on the shorter term.

 

External forcing such as insolation, aerosol scattering and greenhouse gases provide the baseline energy exchange upon which internal variability overides. Several events such as the Younger Dryas cooling appear to involve changes to the thermohaline circulation or maybe something else, yet the system rebounds to near the radiatively forced equilibrium over time. The long term decline in global temperature since the Holocene Thermal Maximum 8,000 years ago correlates with the net condition of orbital forcing as does the pulsing of ice ages over the past 3 million years.

[StudentOfClimatology]

External forcing such as insolation, aerosol scattering and greenhouse gases provide the baseline energy exchange upon which internal variability overides. Several events such as the Younger Dryas cooling appear to involve changes to the thermohaline circulation or maybe something else, yet the system rebounds to near the radiatively forced equilibrium over time. The long term decline in global temperature since the Holocene Thermal Maximum 8,000 years ago correlates with the net condition of orbital forcing as does the pulsing of ice ages over the past 3 million years.

Sure, but that's only true on a 75-100,000 year resolution. Ample peer reviewed literature has clearly identified shorter-duration climate cycles within interstadials, most on a resolution/timespan of 400-800 years. These swings in global temperature of 0.5-1.5C can be attributed to changes in tropical & mid-latitude circulation & convective regimens. They work much like ENSO does, just on longer timescales. They don't appear to be related to solar or aerosol forcing.

The ice age cycles are forced by a redistribution of solar radiation mostly via obliquity that alters the planetary thermal gradient, altering the Hadley & Ferrel cells, resulting in an (initial) warming of the tropics and a cooling of the poles. Solar remains constant, it's just redistributed over the planetary surface. Polar albedo increase is merely a result of the cooling, not a primary cause or dominating feedback. Otherwise there's no mechanism available to end an ice age. The changes in circulation are the dominant "forcings".

The last ice age ended in about 15 years. What happened was that an abrupt shift in the global circulatory network occurred, leading to a rapid warming in the high latitudes. The ice sheets took thousands of years to melt away.

[PhillipS]

Sure, but that's only true on a 75-100,000 year resolution. Ample peer reviewed literature has clearly identified shorter-duration climate cycles within interstadials, most on a resolution/timespan of 400-800 years. These swings in global temperature of 0.5-1.5C can be attributed to changes in tropical & mid-latitude circulation & convective regimens. They work much like ENSO does, just on longer timescales. They don't appear to be related to solar or aerosol forcing.

The ice age cycles are forced by a redistribution of solar radiation mostly via obliquity that alters the planetary thermal gradient, altering the Hadley & Ferrel cells, resulting in an (initial) warming of the tropics and a cooling of the poles. Solar remains constant, it's just redistributed over the planetary surface. Polar albedo increase is merely a result of the cooling, not a primary cause or dominating feedback. Otherwise there's no mechanism available to end an ice age. The changes in circulation are the dominant "forcings".

The last ice age ended in about 15 years. What happened was that an abrupt shift in the global circulatory network occurred, leading to a rapid warming in the high latitudes. The ice sheets took thousands of years to melt away.

 

Please provide a link to research showing that 15 year end to the last ice age.  That figure is not consistent with anything I've read.

[StudentOfClimatology]

Please provide a link to research showing that 15 year end to the last ice age. That figure is not consistent with anything I've read.

Pretty easy to research this stuff. My research is focused in paleoclimate, so I can tell you the terminations I'm referencing are estimated to have occurred over a period of 6 months to 80 years:

http://m.sciencemag.org/content/321/5889/680.short

The last two abrupt warmings at the onset of our present warm interglacial period, interrupted by the Younger Dryas cooling event, were investigated at high temporal resolution from the North Greenland Ice Core Project ice core. The deuterium excess, a proxy of Greenland precipitation moisture source, switched mode within 1 to 3 years over these transitions and initiated a more gradual change (over 50 years) of the Greenland air temperature, as recorded by stable water isotopes. The onsets of both abrupt Greenland warmings were slightly preceded by decreasing Greenland dust deposition, reflecting the wetting of Asian deserts. A northern shift of the Intertropical Convergence Zone could be the trigger of these abrupt shifts of Northern Hemisphere atmospheric circulation, resulting in changes of 2 to 4 kelvin in Greenland moisture source temperature from one year to the next.

In other word, an abrupt shift in the global Hadley Cells appears to be the culprit.

High-Resolution Greenland Ice Core Data Show Abrupt Climate Change Happens in Few Years

Jørgen Peder Steffensen1,*,

Katrine K. Andersen1,

Matthias Bigler1,2,

Henrik B. Clausen1,

Dorthe Dahl-Jensen1,

Hubertus Fischer2,3,

Kumiko Goto-Azuma4,

Margareta Hansson5,

Sigfús J. Johnsen1,

Jean Jouzel6,

Valérie Masson-Delmotte6,

Trevor Popp7,

Sune O. Rasmussen1,

Regine Röthlisberger2,8,

Urs Ruth3,

Bernhard Stauffer2,

Marie-Louise Siggaard-Andersen1,

Árný E. Sveinbjörnsdóttir9,

Anders Svensson1,

James W. C. White7

1 Centre for Ice and Climate, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen OE, Denmark.

2 Climate and Environmental Physics, Physics Institute, University of Bern, Sidlerstrasse 5, CH-3012, Switzerland.

3 Alfred-Wegener-Institute for Polar- and Marine Research (AWI), Postfach 120161, D-27515 Bremerhaven, Germany.

4 National Institute of Polar Research, Kaga 1-9-10, Itabashi-ku, Tokyo 173-8515, Japan.

5 Department of Physical Geography and Quaternary Geology, Stockholm University, S-106 91, Stockholm, Sweden.

6 Institut Pierre Simon Laplace/Laboratoire des Sciences du Climat et de l'Environnement, Commissariat à l'Énergie Atomique (CEA)–CNRS–Université de Versailles Saint Quentin en Yvelines, CEA Saclay, 91191 Gif-Sur-Yvette, France.

7 The Institute of Arctic and Alpine Research, Campus Box 450, University of Colorado, Boulder, CO 80309-0450, USA.

8 British Antarctic Survey, Natural Environment Research Council, High Cross, Madingley Road, Cambridge CB3 0ET, UK.

9 Raunvísindastofnun Háskálans, Dunhagi 3, Iceland.

↵* To whom correspondence should be addressed. E-mail: [email protected]

[wildweatherman179]

Thank you WeatherRusty and SofC for answers and explanations. I also appreciate viewpoints being brought forward in an objective manner. That's the way a discussion is supposed to be.

[PhillipS]

Pretty easy to research this stuff. My research is focused in paleoclimate, so I can tell you the terminations I'm referencing are estimated to have occurred over a period of 6 months to 80 years:

http://m.sciencemag.org/content/321/5889/680.short

In other word, an abrupt shift in the global Hadley Cells appears to be the culprit.

 

 

SOC - the link you provided to the Steffensen et al 2008 paper doesn't provide much support for your assertion that the last Ice Age ended in about 15 years.  Did you read the comments on the paper?  From the Severinghaus and Alley comment:

 

The conclusion of Steffensen et al. is based on the use of a statistical approach called RAMPFIT (1), which assumes that the change in a climate proxy indicator is a linear "ramp" between two states, and that the actual signal measured in the ice core is some combination of random noise plus this linear ramp. However, if the ramp is not linear then the RAMPFIT approach gives an incorrect answer for the timing of the onset of the change. In fact, there is no reason to expect dust or calcium to behave in a linear (or logarithmic) fashion across these climatic transitions. Hence, we believe these data do not support the conclusion that Asian dust changed before Greenland moisture source temperature.

We note further that Steffensen et al. discuss two primarily southern indicators (dust and calcium) and three primarily northern indicators (deuterium excess, isotopic ratio, and annual-layer thickness). The south-leads hypothesis suggests that the order of events should be SSNNN at both transitions, but the central estimates for the starting times of the two ramps [their Table 1 (2)] are SNSNN and (N=S)SNN. Including the uncertainties associated with inadequacy of the RAMPFIT assumptions, many phasings are possible including northern lead, southern lead, synchronous, or more complex patterns. We look forward to additional discussion and data on these questions, and to the anticipated data from completion of the new North Eem core.

And from the Chiang comment:

In our view, this is an implausible scenario. When the northern high latitudes are cool, the interhemispheric temperature gradient shifts the ITCZ southward (1, 2). If cool conditions in the north are due to a slowdown of the Atlantic Meridional Overturning circulation (AMOC), changes to the ocean heat transport result in a weak warming of the southern hemisphere, but this augments the existing interhemispheric gradient. We know of no physical or model justification for the threshold effect proposed by Steffensen et al.

The hypothesis of Steffensen et al. is justified mostly by two observations (i) that there is a slight lead of dust concentration changes in the ice (indicating climate change in the low-latitude Asian source region) to the climate transition; and (ii) that the deuterium excess (hereafter, "excess") jumps abruptly, indicating a rapid location change of the moisture source. We consider each, in turn.

Given that interannual fluctuations of the measured dust are large, the slight lead in the dust to the isotopic transitions is not significant; it is not convincing to define the start of a dust transition when the concentration is well within interannual variability. The dust concentration is also interrelated with the snowfall and with the winds; at the timescale of a few years, it is a dubious measure of the Asian source region climate. Instead, most of the dust change occurs after the isotopic transitions, consistent with an increase of the Asian monsoon as the AMOC speeds up [e.g. (3)], with a few years' lag for the Asian land surface to respond.

 

We agree with Steffensen et al. that the excess data indicate an abrupt change in the moisture sources. However, it has long been recognized that changes to sea ice cover will change the balance of moisture sources, and hence the excess (4, 5). Steffensen et al. argue against sea ice changes, as "sea ice extended far south during the final phase of the cold stadials and is not expected to break down in just 1 to 3 years." This is a strange claim, since sea ice cover grows and shrinks dramatically over a seasonal cycle. During cold periods, that seasonality was even larger because the amplitude of annual temperature variations was greater (6). A rapid change in sea ice cover requires only reduced formation in one winter season. Because the edge of winter sea ice in the cold period is well south of the ice sheet, it is not surprising that the Greenland climate continues to adjust in subsequent years while the balance of moisture sources, dominated by warmer oceans to the south, does not.

If I have time later today I'll look for more recent literature, but it seems to me that the Steffensen paper is a pretty shaky prop for your assertion that "The last ice age ended in about 15 years.".  Your claiming that specific a time frame for what was a globe altering event is extraordinary, and as the old saying goes - extraordinary claims need extraordinary evidence.

[WeatherRusty]

Sure, but that's only true on a 75-100,000 year resolution. Ample peer reviewed literature has clearly identified shorter-duration climate cycles within interstadials, most on a resolution/timespan of 400-800 years. These swings in global temperature of 0.5-1.5C can be attributed to changes in tropical & mid-latitude circulation & convective regimens. They work much like ENSO does, just on longer timescales. They don't appear to be related to solar or aerosol forcing.

The ice age cycles are forced by a redistribution of solar radiation mostly via obliquity that alters the planetary thermal gradient, altering the Hadley & Ferrel cells, resulting in an (initial) warming of the tropics and a cooling of the poles. Solar remains constant, it's just redistributed over the planetary surface. Polar albedo increase is merely a result of the cooling, not a primary cause or dominating feedback. Otherwise there's no mechanism available to end an ice age. The changes in circulation are the dominant "forcings".

The last ice age ended in about 15 years. What happened was that an abrupt shift in the global circulatory network occurred, leading to a rapid warming in the high latitudes. The ice sheets took thousands of years to melt away.

 

I don't really have issue with the concept of abrupt climate change. The Younger Dryas is an example of that. So is the PETM etc. However, the causes are what is in question. Major flips in ocean and atmospheric circulation don't just happen without cause. Or do they? If there are quasi regular cycles what are the mechanisms? Solar variability?

 

The changing distribution of solar energy latitudally due to orbital factors is as you state the trigger for the pulsing of the ice ages. The actual flip in climate condition may occur rather suddenly in response to a more gradual forcing. An analogy may be the sudden release of gradually built up energy in a sismic fault causing an Earthquake.

 

"The long term decline in global temperature since the Holocene Thermal Maximum 8,000 years ago correlates with the net condition of orbital forcing as does the pulsing of ice ages over the past 3 million years."

 

The gradual decline in global averaged temperature over the past several 1,000 years being a reflection of orbial forcing was the point I was trying to make. For the current day Earth, longer term climate regimes are externally forced it would seem and on much shorter time scales than 75,000 years.

[StudentOfClimatology]

I don't really have issue with the concept of abrupt climate change. The Younger Dryas is an example of that. So is the PETM etc. However, the causes are what is in question. Major flips in ocean and atmospheric circulation don't just happen without cause. Or do they? If there are quasi regular cycles what are the mechanisms? Solar variability?

I doubt it's solar, but who knows. Could be internal resonance, much like a long term ENSO. I don't know, though. It's something the paleoclimate community is trying to figure out, despite people like "PhillipS" who try to cloud the issue with a bunch of hypotheticals that ignore the observations.

Obviously the current global warming is largely anthropogenic. There's no doubt about that.

The changing distribution of solar energy latitudally due to orbital factors is as you state the trigger for the pulsing of the ice ages. The actual flip in climate condition may occur rather suddenly in response to a more gradual forcing. An analogy may be the sudden release of gradually built up energy in a sismic fault causing an Earthquake.

"The long term decline in global temperature since the Holocene Thermal Maximum 8,000 years ago correlates with the net condition of orbital forcing as does the pulsing of ice ages over the past 3 million years."

The gradual decline in global averaged temperature over the past several 1,000 years being a reflection of orbial forcing was the point I was trying to make. For the current day Earth, longer term climate regimes are externally forced it would seem and on much shorter time scales than 75,000 years.

Okay, I see what you mean now. I'm in agreement.

[StudentOfClimatology]

SOC - the link you provided to the Steffensen et al 2008 paper doesn't provide much support for your assertion that the last Ice Age ended in about 15 years. Did you read the comments on the paper? From the Severinghaus and Alley comment:

The conclusion of Steffensen et al. is based on the use of a statistical approach called RAMPFIT (1), which assumes that the change in a climate proxy indicator is a linear "ramp" between two states, and that the actual signal measured in the ice core is some combination of random noise plus this linear ramp. However, if the ramp is not linear then the RAMPFIT approach gives an incorrect answer for the timing of the onset of the change. In fact, there is no reason to expect dust or calcium to behave in a linear (or logarithmic) fashion across these climatic transitions. Hence, we believe these data do not support the conclusion that Asian dust changed before Greenland moisture source temperature.

We note further that Steffensen et al. discuss two primarily southern indicators (dust and calcium) and three primarily northern indicators (deuterium excess, isotopic ratio, and annual-layer thickness). The south-leads hypothesis suggests that the order of events should be SSNNN at both transitions, but the central estimates for the starting times of the two ramps [their Table 1 (2)] are SNSNN and (N=S)SNN. Including the uncertainties associated with inadequacy of the RAMPFIT assumptions, many phasings are possible including northern lead, southern lead, synchronous, or more complex patterns. We look forward to additional discussion and data on these questions, and to the anticipated data from completion of the new North Eem core.

And from the Chiang comment:

In our view, this is an implausible scenario. When the northern high latitudes are cool, the interhemispheric temperature gradient shifts the ITCZ southward (1, 2). If cool conditions in the north are due to a slowdown of the Atlantic Meridional Overturning circulation (AMOC), changes to the ocean heat transport result in a weak warming of the southern hemisphere, but this augments the existing interhemispheric gradient. We know of no physical or model justification for the threshold effect proposed by Steffensen et al.

The hypothesis of Steffensen et al. is justified mostly by two observations (i) that there is a slight lead of dust concentration changes in the ice (indicating climate change in the low-latitude Asian source region) to the climate transition; and (ii) that the deuterium excess (hereafter, "excess") jumps abruptly, indicating a rapid location change of the moisture source. We consider each, in turn.

Given that interannual fluctuations of the measured dust are large, the slight lead in the dust to the isotopic transitions is not significant; it is not convincing to define the start of a dust transition when the concentration is well within interannual variability. The dust concentration is also interrelated with the snowfall and with the winds; at the timescale of a few years, it is a dubious measure of the Asian source region climate. Instead, most of the dust change occurs after the isotopic transitions, consistent with an increase of the Asian monsoon as the AMOC speeds up [e.g. (3)], with a few years' lag for the Asian land surface to respond.

We agree with Steffensen et al. that the excess data indicate an abrupt change in the moisture sources. However, it has long been recognized that changes to sea ice cover will change the balance of moisture sources, and hence the excess (4, 5). Steffensen et al. argue against sea ice changes, as "sea ice extended far south during the final phase of the cold stadials and is not expected to break down in just 1 to 3 years." This is a strange claim, since sea ice cover grows and shrinks dramatically over a seasonal cycle. During cold periods, that seasonality was even larger because the amplitude of annual temperature variations was greater (6). A rapid change in sea ice cover requires only reduced formation in one winter season. Because the edge of winter sea ice in the cold period is well south of the ice sheet, it is not surprising that the Greenland climate continues to adjust in subsequent years while the balance of moisture sources, dominated by warmer oceans to the south, does not.

If I have time later today I'll look for more recent literature, but it seems to me that the Steffensen paper is a pretty shaky prop for your assertion that "The last ice age ended in about 15 years.". Your claiming that specific a time frame for what was a globe altering event is extraordinary, and as the old saying goes - extraordinary claims need extraordinary evidence.

The opinions you cite are deep in the minority, and are contradicted by the latest literature. The data is pretty clear on this, and here are dozens of peer reviewed papers on this topic published in the last 6yrs that come to the same conclusion.

Here's another good paper:

http://www.nature.com/nature/journal/v391/n6663/abs/391141a0.html

Timing of abrupt climate change at the end of the Younger Dryas interval from thermally fractionated gases in polar ice

Jeffrey P. Severinghaus1, Todd Sowers2, Edward J. Brook3, Richard B. Alley2 & Michael L. Bender4

Graduate School of Oceanography, University of Rhode Island, Narragansett, Rhode Island 02882, USA

Geosciences Department, Pennsylvania State University, University Park, Pennsylvania 16802, USA

Departments of Geology and Environmental Science, Washington State University, Vancouver, Washington 98686, USA

Present address: Department of Geosciences, Princeton University, Princeton, New Jersey 08544, USA.

Correspondence to: Jeffrey P. Severinghaus1 Correspondence and requests for materials should be addressed to J.P.S. (e-mail: Email: [email protected].)

Rapid temperature change fractionates gas isotopes in unconsolidated snow, producing a signal that is preserved in trapped air bubbles as the snow forms ice. The fractionation of nitrogen and argon isotopes at the end of the Younger Dryas cold interval, recorded in Greenland ice, demonstrates that warming at this time was abrupt. This warming coincides with the onset of a prominent rise in atmospheric methane concentration, indicating that the climate change was synchronous (within a few decades) over a region of at least hemispheric extent, and providing constraints on previously proposed mechanisms of climate change at this time. The depth of the nitrogen-isotope signal relative to the depth of the climate change recorded in the ice matrix indicates that, during the Younger Dryas, the summit of Greenland was 15 plusminus 3 °C colder than today.

Here's another interesting paper, more future-oriented:

http://m.sciencemag.org/content/300/5625/1519.short

Slowing down as an early warning signal for abrupt climate change

In the Earth's history, periods of relatively stable climate have often been interrupted by sharp transitions to a contrasting state. One explanation for such events of abrupt change is that they happened when the earth system reached a critical tipping point. However, this remains hard to prove for events in the remote past, and it is even more difficult to predict if and when we might reach a tipping point for abrupt climate change in the future. Here, we analyze eight ancient abrupt climate shifts and show that they were all preceded by a characteristic slowing down of the fluctuations starting well before the actual shift. Such slowing down, measured as increased autocorrelation, can be mathematically shown to be a hallmark of tipping points. Therefore, our results imply independent empirical evidence for the idea that past abrupt shifts were associated with the passing of critical thresholds. Because the mechanism causing slowing down is fundamentally inherent to tipping points, it follows that our way to detect slowing down might be used as a universal early warning signal for upcoming catastrophic change. Because tipping points in ecosystems and other complex systems are notoriously hard to predict in other ways, this is a promising perspective.

[PhillipS]

The opinions you cite are deep in the minority, and are contradicted by the latest literature. The data is pretty clear on this, and here are dozens of peer reviewed papers on this topic published in the last 6yrs that come to the same conclusion.

Here's another good paper:

http://www.nature.com/nature/journal/v391/n6663/abs/391141a0.html

Here's another interesting paper, more future-oriented:

http://m.sciencemag.org/content/300/5625/1519.short

 

 

Nope, SOC, that's another swing and a miss for you.  I didn't ask it took for the Younger Dryas stadial to end, nor did I ask for research on rapid climate change.  I asked the pretty simple question of where you got your value of "about 15 years" for the end of the last Ice Age.  You still have not answered that question.

 

In plain English, "about 15 years" means more than 10 years and fewer than 20 years.  Agree?  A value that specific far exceeds the resolution of most proxies so my question is a fair one.  Is that a published value from peer-reviewed research for the end of the last Ice Age - or is it just your opinion masquerading as research?  There is nothing wrong with offering your opinion of topics (most of us on this forum have done so), but when you claim your opinion as fact then you're being dishonest.

 

So please provide us the link to the "about 15 year" value - or fess up to your actions.