Leading Paleoclimatologist: Prepare for the Next Ice Age

[Snow_Miser]

Time to prepare for the next Ice Age says George Kukla.

The "Earth has experienced an ongoing cycle of ice ages dating back millions of years. Cold, glacial periods affecting the polar to mid-latitudes persist for about 100,000 years, punctuated by briefer, warmer periods called interglacials," Kukla says.<BR itxtNodeId="124"><BR itxtNodeId="123">Co-author of an important section of the book "Natural Climate Variability on Decade to Century Time Scales," Kukla asserts all Ice Ages start with a period of global warming. They are the harbingers of new Ice Ages. Actually, he explains, warming is good. Ice Ages are deadly and may even kill millions.<BR itxtNodeId="122"><BR itxtNodeId="121">Can Mankind stop it? No. Just as humanity cannot affect the long term climate of the planet, neither can it stop an Ice Age from happening. The climate is primarily driven by the sun.<BR itxtNodeId="120"><BR itxtNodeId="119">"I feel we're on pretty solid ground in interpreting orbit around the sun as the primary driving force behind Ice Age glaciation," he says. "The relationship is just too clear and consistent to allow reasonable doubt. It's either that, or climate drives orbit, and that just doesn't make sense."<BR itxtNodeId="118"><BR itxtNodeId="117">

http://www.helium.com/items/2125333-prepare-for-new-ice-age-now-says-top-paleoclimatologist

[tacoman25]

There is no doubt that an Ice Age would be more harmful for humanity than AGW. However, it's impossible to say when the next ice age will commence. AGW represents a much more imminent threat, though to what degree is very debatable.

Some scientists believe AGW could actually prevent the next ice age from occurring at all, though that seems presumptious to me, since we don't really understand the exact mechanism that cause ice ages to occur.

[skierinvermont]

Why can't some people tell the difference between fringe whackjob sources and actual science?

This is how a scientist writes and works:

http://www.gfdl.noaa...log/isaac-held/

This is how a fringe whackjob tries to get media attention:

http://www.helium.co...eoclimatologist

Try reading both and see if you can tell the difference. One comes across as a totally uncredible moron, the other comes across as a professional intellectual.

[Snow_Miser]

Why can't some people tell the difference between fringe whackjob sources and actual science?

So a leading paleoclimatologist's opinion doesn't matter?

[skierinvermont]

So a leading paleoclimatologist's opinion doesn't matter?

Leading according to who? Helium.com?

[BethesdaWX]

Time to prepare for the next Ice Age says George Kukla.

http://www.helium.co...eoclimatologist

All this ice age stuff is 10X as ridiculous as mass AGW imo, there is no way to predict the end of the Holocene.

The Milankovitch Cycles actually do not correlate well with Ice ages.

http://creation.com/images/pdfs/tj/j12_1/j12_1_9-10.pdf

[BethesdaWX]

Why can't some people tell the difference between fringe whackjob sources and actual science?

This is how a scientist writes and works:

http://www.gfdl.noaa...log/isaac-held/

This is how a fringe whackjob tries to get media attention:

http://www.helium.co...eoclimatologist

Try reading both and see if you can tell the difference. One comes across as a totally uncredible moron, the other comes across as a professional intellectual.

Yes, one writes less proffessionally, but that doesn't have anything to do with the accuracy of the science at hand. Don't get me wrong, I think its stupid to try and predict an ice age, but I think both sides are going nuts with assuptions.

The issue with AGW is feedbacks, in order for AGW to work, we need a strong set of positive feedbacks within the climate system. However, not only is our knowledge piss poor regarding Clouds, how PDO/AMO influence them, and how 10/BE conc correlate, but there is growing evidence the climate system is stacked with negative feedbacks, not positive feedbacks.

This is already manifesting in satellite data! With the TERRA satellite launched in 2000, we can measure radiative feedbacks and non-radiative feedbacks from the planet. We see both Feedback loops and linear Striations. To make the matter laughable, the radiative imabalance from increased CO2 emissions was too small to measure, and still is

When the slope accompanying the lines is positive, it reflects a strong positive feedback.

The plot shows two types of patterns; linear striations and random spiral patterns. The usual interpretation of this data by climate modelers would be to use the best fit line which shows a slope of 0.7 W/m2/C, which is a very high positive feedback. The actual feedback should be determined by the slope of the linear striations, which is 8 W/m2/C, which is a very high negative feedback. A value of 3.3 W/m2/C corresponds to no feedback. (No feedback means if the temperature of the atmosphere were uniformly increased by 1 C and nothing else changed, the top of the atmosphere would radiate 3.3 W/m2 more radiation to space.) The feedback is observed to occur on shorter time scales in response to evaporation and precipitation events, which are superimposed upon a more slowly varying background of radiative imbalance due to natural fluctuation in cloud cover changing the rate of solar heating Earth’s surface.

The satellite data shows that over short time scales, clouds provide strong negative feedbacks. Spencer also analyzed the radiative flux and temperature variations from climate models used by the IPCC to determine if the short term negative feedback found in the satellite data is also applicable to long term feedback. He found that the short term linear striations and the spiral patterns show up all 18 climate models that he analyzed. Spencer says the slopes of the linear striations do indeed correspond to the long term feedbacks diagnosed from these models’ response to anthropogenic greenhouse gas forcing. This strongly suggests that the short term negative feedback shown in satellite data also applies to long term global climate change.

The feedback estimate for a hypothetical doubling of carbon dioxide, using the Terra satellite data gives a climate sensitivity of 0.46 C.

[skierinvermont]

That Spencer "striation" argument has been widely debunked. It makes little sense. There is no expectation that feedbacks will operate the same over a period of months as over periods of decades. Spencer is completely outside his field when commenting on such science.

He's also being hypocritical and self-contradictory.. in the scientific paper he published (Spencer and Braswell) they do not say that these "linear striations" are evidence of low feedback. He only claims this on his blog. In the actual scientific paper he admits that they may be only indicative of seasonal feedback or may not be indicative of anything at all. To then go on his blog and claim that they ARE evidence of negative feedbacks is hypocritical.

[skierinvermont]

A much better and clearer analysis of ERBE radiation data than Spencer and Braswell is. The gist of it is that when SSTs rapidly warm we expect outgoing LW radiation to increase 3.7W/m2/C. If it increases more than this, it is evidence that SST warming is producing negative feedbacks, if it increases less than this, it indicates there are positive feedbacks. Basically, what it indicates is that when SSTs rapidly warm, the outgoing radiation is not increasing by 3.7W/m2 because positive feedbacks such as increasing water vapor are acting to decrease outgoing LW radiation.

http://journals.amet...1175/JCLI3611.1

If you are interested in the water vapor feedback, check out these references. There is no doubt that the WV feedback is strongly positive.

Dessler, A. E., Z. Zhang, and P. Yang (2008), Water-vapor climate feedback inferred from climate fluctuations, 2003–2008, Geophys. Res. Lett., 35, L20704

Gettelman A and Fu, Q. (2008) Observed and simulated upper-tropospheric water vapor feedback J. Climate 21, 3282-3289

Buehler SA (2008) An upper tropospheric humidity data set from operational satellite microwave data. J. Geophys. Res. 113, art #D14110

Brogniez H and Pierrehumbert RT (2007) Intercomparison of tropical tropospheric humidity in GCMs with AMSU-B water vapor data> Geophys. Res. Lett. 34, art #L17912

Santer BD et al. (2007) Identification of human-induced changes in atmospheric moisture content. Proc. Natl. Acad. Sci. USA 104, 15248-15253

Soden BJ, et al (2005) The radiative signature of upper tropospheric moisteningScience 310, 841-844.

For low level cloud feedback,

http://www.sciencema.../5939/460.short

[BethesdaWX]

That Spencer "striation" argument has been widely debunked. It makes little sense. There is no expectation that feedbacks will operate the same over a period of months as over periods of decades. Spencer is completely outside his field when commenting on such science.

This isn't water vapor feedback.

The physical feedback itself cannot change, its physics, its the assumed trend that is in question since we cannot measure GCC........Low Level Cloud Cover is a HUGE Negative feedback, while Mid and Upper Level clouds are Positive feedbacks.............Satellite measurements showing the strong negaive feedback in overall regards over the Past 11 years in Radiative and Non-Radiative feedbacks in regards cannot be debunked, because there is no alternative data. Its not "Spencer's" Creation.

However as you may have been trying to say, the problem with his theory is assuming that one level of cloudiness (one that would cause a feedback) will trend as a Constant (Forcing doesn't always = feedback), which is not necessarily true

But that, fortunately for Spencer, cannot inflict error upon the final result if the feedback was shown to be negative to start, as in, to the trend RESULTING from feedback non-radiatively (feedbacks), rather than as a forcings component.....as has been measured through satellite data. The "tail" of the data will never get to zero!

But the misconstruding issue here are IPCC models using a string of Positive feedbacks in the Climate system, which is not the Case. THIS is the reason why we're fallen out of the IPCC cone of confidence, for good this time

[skierinvermont]

Even in his own scientific paper, Spencer contradicts the "linear striation" argument he has posted on his blog. In his own scientific paper he says that these linear striations are not necessarily indicative of negative feedbacks to warming. He is contradicting himself.. it's utter hypocrisy.

They might indicate a negative feedback to seasonal warming. However.. as we see from his graph... when temperatures are warmer outgoing LW radiation in general does not increase by the theoretical 3.3W/m2/C.. it increases much less than that... at around .7W/m2/C. Indicating strong positive feedback to the warming which is acting to further trap outgoing LW radiation. The predominant positive feedback is clearly water vapor, which we know increases rapidly during periods of warming. We thus conclude that the feedback to warming is positive.

[BethesdaWX]

I'm beginning to get the notion that Skier believes that Low Level Cloud Cover is a Positive feedback... I hope I'm wrong.

Cloud Changes Act upon the Climate System, that hasn't changed with CO2. What needs to be realized here, feedback from CO2 on WV is not the same thing as Clouds Reflecting Light back into Space.

ftp://eos.atmos.wash...iller_jcl97.pdf

[skierinvermont]

I'm beginning to get the notion that Skier believes that Low Level Cloud Cover is a Positive feedback... I hope I'm wrong.

Cloud Changes Act upon the Climate System, that hasn't changed with CO2. What needs to be realized here, feedback from CO2 on WV is not the same thing as Clouds Reflecting Light back into Space.

ftp://eos.atmos.wash...iller_jcl97.pdf

You are not using the terms properly. Low level cloud cover decreases temperature. This does NOT make it a negative feedback. That depends whether low level cloud cover increases or decreases in response to warming.

There is evidence that low level cloud cover will decrease in response to warming, creating a positive feedback.

[BethesdaWX]

Even in his own scientific paper, Spencer contradicts the "linear striation" argument he has posted on his blog. In his own scientific paper he says that these linear striations are not necessarily indicative of negative feedbacks to warming. He is contradicting himself.. it's utter hypocrisy.

They might indicate a negative feedback to seasonal warming. However.. as we see from his graph... when temperatures are warmer outgoing LW radiation in general does not increase by the theoretical 3.3W/m2/C.. it increases much less than that... at around .7W/m2/C. Indicating strong positive feedback to the warming which is acting to further trap outgoing LW radiation. The predominant positive feedback is clearly water vapor, which we know increases rapidly during periods of warming. We thus conclude that the positive feedback to warming is 2.5 W/m2/C.

Thus the expected forcing to a doubling of CO2 is 6.2W/m2 including positive feedbacks (3.7+2.5=6.2)

Try emailing Him, I'm sure he'll expain.....feedbacks TO warming.....FROM warming.... Come on dude...It starts with assuming that the Warming is Man Made from the Start, when cloud changes themselves could explain the warming without much help.

If I give the IPCC the benefit of the doubt, assuming that Low Level clouds are a positive feedback...............AGW theory is in even more trouble than we would have thought. WIth CO2 around 400ppm, positive feedbacks in Climate Models, we'd need to be MUCH warmer right now.

[BethesdaWX]

There is evidence that low level cloud cover will decrease in response to warming, creating a positive feedback.

What evidence? Its an assumption! A freakin assuption, a correlation! Its no more than that.

Models results are not evidence, because they assume that the climate system is rigged with positive feedbacks.

There is also "evidence" it works the other way around, but that is also an assumption.

[skierinvermont]

Not true at all.. as we've been through numerous times IPCC models predict the last century of climate accurately and although we are currently on the low side of their confidence interval, there is no statistical invalidation of them at this point. If the 2010s had little or no warming, then they would be statistically rejected.

[BethesdaWX]

Not true at all.. as we've been through numerous times IPCC models predict the last century of climate accurately and although we are currently on the low side of their confidence interval, there is no statistical invalidation of them at this point.

Problem is, in order for the Theory to Work, the temperature would have to have remained Flat before the 20th Century, or faily much so.

Take Tree Ring Proxies out of the Proxy Data, and you get the better answer, tree ring data is terrible for temperature.

The Changing Climate before the 20th Century Invalidates the IPCC models, because we assume that no other forcing besides CO2 can change temperature to the extent it has today...that is incorrect.

[BethesdaWX]

Show me one model that has used "Cloud Cover" as a forcing.....that is physically impossible to do at this point because WE CANNOT MEASURE GLOBAL CLOUD COVER TODAY

Again, assuming is Warming = Less GCC, and Not the Other way Around.

[Isotherm]

There is no doubt that an Ice Age would be more harmful for humanity than AGW. However, it's impossible to say when the next ice age will commence. AGW represents a much more imminent threat, though to what degree is very debatable.

Some scientists believe AGW could actually prevent the next ice age from occurring at all, though that seems presumptious to me, since we don't really understand the exact mechanism that cause ice ages to occur.

It makes more sense that AGW would actually cause us to accelerate toward a mini ice age. Greater quantities of fresh water release from Greenland could slow the thermohaline circulation in the Atlantic, eventually resulting in a cool down over NA and Europe (up to 3-5 degrees C from the sources I've read). In turn, ice sheets across the nern hemisphere would begin expanding southward.

Now, whether or not we're at that time frame atm is up for debate. I don't think anyone can predict exactly when an ice age will start, but there is no doubt in my mind the next couple decades will feature global temperatures heading downward (based upon solar and oceanic factors).

[skierinvermont]

Problem is, in order for the Theory to Work, the temperature would have to have remained Flat before the 20th Century, or faily much so.

Take Tree Ring Proxies out of the Proxy Data, and you get the better answer, tree ring data is terrible for temperature.

The Changing Climate before the 20th Century Invalidates the IPCC models, because we assume that no other forcing besides CO2 can change temperature to the extent it has today...that is incorrect.

Again, not true. As I have explained several times IPCC models accurately simulate the last 1,000 years of climate fluctuations including a MWP and LIA.

[skierinvermont]

there is no doubt in my mind the next couple decades will feature global temperatures heading downward (based upon solar and oceanic factors).

Highly unlikely IMO. But at least you are willing to put the theory to test (Landsheidt predicted cooling in the 2000s actually). Hopefully in 10 years when we have continued to warm you'll reconsider the strong science behind AGW.

[skierinvermont]

Show me one model that has used "Cloud Cover" as a forcing.....that is physically impossible to do at this point because WE CANNOT MEASURE GLOBAL CLOUD COVER TODAY

Again, assuming is Warming = Less GCC, and Not the Other way Around.

All the major models include simulated changes in cloud cover.. again you reveal your complete unfamiliarity with the actual science on this subject.

IPCC figure 2.20

\

IPCC figure 8.14

The above figure shows feedbacks for water vapor, clouds, aerosols... etc. using a variety of metrics of feedback strength (PRP, RCMs, etc.)

[tacoman25]

Not true at all.. as we've been through numerous times IPCC models predict the last century of climate accurately and although we are currently on the low side of their confidence interval, there is no statistical invalidation of them at this point. If the 2010s had little or no warming, then they would be statistically rejected.

This doesn't mean as much as you think it does. Predicting the past based on set, observed variables does not necessarily equal accurate results in the future. Anyone who has worked much with theoretical models knows this...or should.

[Isotherm]

Highly unlikely IMO. But at least you are willing to put the theory to test (Landsheidt predicted cooling in the 2000s actually). Hopefully in 10 years when we have continued to warm you'll reconsider the strong science behind AGW.

Honestly, I try to be as open minded as possible, and would switch sides of the debate if I saw that objective science was strong enough, but the AGW arguement is far weaker than the natural argument IMO. Maybe we'll be warmer in 10 years, although I'd be willing to bet my life savings that it won't be. There's no question anthropogenic activities are contributing slightly to the warming, but nowhere near enough to combat other natural forcings. The Co2-temp correlation has broken down to almost 0 over the past decade.

[skierinvermont]

This doesn't mean as much as you think it does. Predicting the past based on set, observed variables does not necessarily equal accurate results in the future. Anyone who has worked much with theoretical models knows this...or should.

It does if the models are based upon theoretical physics (which they are) and then used to predict past climate.

If they "cheat" and tweak the models so as to predict past climate, it becomes less meaningful (though not meaningless).

[tacoman25]

Highly unlikely IMO. But at least you are willing to put the theory to test (Landsheidt predicted cooling in the 2000s actually). Hopefully in 10 years when we have continued to warm you'll reconsider the strong science behind AGW.

And Hansen predicted considerably more warming than occurred in the 2000s (very little). Does that invalidate his work?

[skierinvermont]

And Hansen predicted considerably more warming than occurred in the 2000s (very little). Does that invalidate his work?

Yes. As Hansen himself has published.

[tacoman25]

It does if the models are based upon theoretical physics (which they are) and then used to predict past climate.

If they "cheat" and tweak the models so as to predict past climate, it becomes less meaningful (though not meaningless).

The problem can be that forcings/feedbacks can fit into trends without necessarily being responsible for them. Assumptions have to be made, and while those may fit into the past, they won't necessarily work in the future.

I read a very interesting article on this subject a couple years ago, I'll see if I can dig it up.

[tacoman25]

Yes. As Hansen himself has published.

Hansen has published something saying his own work is invalidated?

[nzucker]

Highly unlikely IMO. But at least you are willing to put the theory to test (Landsheidt predicted cooling in the 2000s actually). Hopefully in 10 years when we have continued to warm you'll reconsider the strong science behind AGW.

You're making this into too much of a black/white issue: I think Isotherm is saying that both natural and anthropogenic factors are affecting the climate, but that natural factors will be more powerful in the next decade versus the long-term where CO2 becomes important. It doesn't mean that he's not considering the science of AGW, but even using the IPCC accepted rate of warming at .2C or so per decade, it's possible for a strong solar minimum, -PDO/La Niña, and increasing volcanic activity in Iceland to produce cooling.

In my mind, we probably won't cool or warm much this decade...we're off to a slow start so far, and the plateau that started after 1998 looks to continue given the sources of it (low solar, switch to -PDO) are still in place, and to a more extreme level now than they were then. So I don't see much that argues for significant changes to the climate by 2020...the debate will still be raging at that point, I think skeptics will have gained some ground as warming continues to fall short of the .2C-.3C/decade standard accepted by most climatologists/modeling agencies...but in any case, 10 years won't prove AGW wrong or right.