Forcing of Doubling CO2? Positive or negative Feedbacks?

[William]

It should be noted that the quantum allowed orbits of electrons in a gas (Venus, 96.5% CO2 by volume, 90 atmospheres at Venus’ surface.), start to blend, at 90 atmosphere (as the gas changes phase to a liquid). Venus cannot therefore be used as an analogue to what would be the expected out come if CO2 levels were to double (from 380 parts per million C02 to 560 parts per million C02) on the earth at one atmosphere.

It should be noted that CO2 levels on the earth have been 20 times higher than current levels and the temperature was only 7C higher than current levels, so it is not clear why there would be a 3C to 4C increase in planetary temperature if CO2 were to double from current levels.

As others have noted geological evidence indicates that there is not correlation of past CO2 levels and planetary temperature. i.e. In the past there have been significant increases and decreases of CO2 and there was not an accompanying change in planetary temperature.

There is recent publish data and analysis that indicates the amount of direct forcing (without feedbacks) of an increase in CO2 is significant less than that used in the IPCC calculations.

There is recent published data and analysis that indicates the planetary response to a step increase in climate forcing is less than half what was used in the IPCC estimate. The forcing data indicates that planetary cloud cover increases when the planet warms and tropical moisture moves polar ward both of which reduce rather than amplify changes in the forcing. (This conclusion is supported by a 20 times increase in CO2 and only a 7C increase in temperature as well as significant increase and decreases of CO2 levels in the past with no accompanying change in planetary temperature.)

http://icecap.us/images/uploads/DOUGLASPAPER.pdf

A comparison of tropical temperature trends with model predictions by D. Douglass, J. Christy, B. Pearson, and S. Singer

We have tested the proposition that greenhouse model simulations and trend observations can be reconciled. Our conclusion is that the present evidence, with the application of a robust statistical test, supports rejection of this proposition. (The use of tropical tropospheric temperature trends as a metric for this test is important, as this region represents the CEL and provides a clear signature of the trajectory of the climate system under enhanced greenhouse forcing.) On the whole, the evidence indicates that model trends in the troposphere are very likely inconsistent with observations that indicate that, since 1979, there is no significant long-term amplification factor relative to the surface.

If these results continue to be supported, then future projections of temperature change, as depicted in the present suite of climate models, are likely too high...

...In summary, the debate in this field revolves around the idea of discrepancy in surface and tropospheric trends in the tropics where vertical convection dominates heat transfer. Models are very consistent, as this article demonstrates, in showing a significant difference between surface and tropospheric trends, with tropospheric temperature trends warming faster than the surface. What is new in this article is the determination of a very robust estimate of the magnitude of the model trends at each atmospheric layer. These are compared with several equally robust updated estimates of trends from observations which disagree with trends from the models.

Does the Earth Have an Adaptive Infrared Iris? R.Lindzen, Ming-Dah Chou, Arthur Y. Hou

http://www-eaps.mit.edu/faculty/lindzen/adinfriris.pdf

The calculations show that such a change in the Tropics could lead to a negative feedback in the global climate, with a feedback factor of about -1.1, which if correct, would more than cancel all the positive feedbacks in the more sensitive current climate models. Even if regions of high humidity were not coupled to cloudiness, the feedback factor due to the clouds alone would still amount to about -0.45, which would cancel model water vapour feedback in almost all models...

...This new mechanism would, in effect, constitute an adaptive infrared iris that opens and closes in order to control the Outgoing Longwave Radiation in response to changes in surface temperature in a manner similar to the way in which an eye’s iris opens and closes in response to changing light levels. Not surprisingly, for upper-level clouds, their infrared effect dominates their shortwave effect. Preliminary attempts to replicate observations with GCMs suggest that models lack such a negative cloud/moist areal feedback.

[nauthiz]

Research which calls the Douglass paper's results into question has come out since then. Basically, the authors glossed over known accuracy problems in the instrumentation that produced their data, and these problems make it hard to draw any reliable conclusions from the tropical troposphere data.

In-depth discussion at RealClimate.

[lomiller1]

It should be noted that the quantum allowed orbits of electrons in a gas (Venus, 96.5% CO2 by volume, 90 atmospheres at Venus’ surface.), start to blend, at 90 atmosphere (as the gas changes phase to a liquid). Venus cannot therefore be used as an analogue to what would be the expected out come if CO2 levels were to double (from 380 parts per million C02 to 560 parts per million C02) on the earth at one atmosphere.

Pressure spreading of absorption bands does not change the basis for the results. Whatever the absorption bands are, if you prevent energy from escaping to space the whole planet warms up.

It should be noted that CO2 levels on the earth have been 20 times higher than current levels and the temperature was only 7C higher than current

It’s also worth noting that when this happend the suns energy output was 25% lower then it is now.

(that's about 4 doublings of CO2 or 12 deg)

As others have noted geological evidence indicates that there is not correlation of past CO2 levels and planetary temperature. i.e. In the past there have been significant increases and decreases of CO2 and there was not an accompanying change in planetary temperature.

Not true. Changes in CO2 track very well with changes in temperature for a very long time. There may be one or two minor discrepancies but these are so far back in time there is no way to measure either temperature or CO2 with great accuracy at any given time.

I suspect you are simply mixing up your talking point. The usual version of that it some variation on “it was warmer at time x then time y even though CO2 was the same” when time x and y are separated by tens of million or hundreds of millions of years.

There is recent publish data and analysis that indicates the amount of direct forcing (without feedbacks) of an increase in CO2 is significant less than that used in the IPCC calculations.

That’s like saying 1 + 2 + 3 = 4 as long as you ignore the 2. You can’t ignore feedbacks. Without them you can’t have things like solar activity or Milenkovich cycles effecting the earths climate either.

For this reason climate sensitivity includes short term feedbacks by definition. If you calculate it without short term feedbacks it isn’t climate sensitivity.

A comparison of tropical temperature trends with model predictions by D. Douglass, J. Christy, B. Pearson, and S. Singer

As pointed out that paper is both outdated and flawed. Outdated because newer measurement directly contradict it's results and flawed because even if correct it doesn’t mean what it’s purported to. (Tropical hotspots occur in climate models are not unique to greenhouse warming, they show up with any warming at all)

Does the Earth Have an Adaptive Infrared Iris? R.Lindzen, Ming-Dah Chou, Arthur Y. Hou

Lindzen’s hypothesis was discounted a decade ago because it forbade the occurrence of ice ages or the earth ever being warmer then it is today.

[William]

The data from the paper referenced in the attached link provides evidence that contradicts Milankovitch's hypothesis. The data shows that a planet wide forcing function is simultaneously affecting both Northern and Southern Hemisphere. The Northern and Southern hemisphere glacial and interglacial cycle are synchronized. (i.e. The Northern hemisphere and Southern Hemisphere cool and warm at the same time.) The Milankovitch orbital change mechanism is not capable of simultaneously affecting both the Northern and Southern Hemispheres. The insolation changes due to the orbital changes are symmetrically opposite from North to South Hemisphere. i.e. If summers are warmer in the Northern hemisphere due to orbital changes they are colder in Southern hemisphere.

Milankovitch's hypothesis cannot explain why the glacial/interglacial cycle started as a 41kyr cycle and is now a 100 kyr cycle. The interglacial periods are roughly 12kyrs long and contrary to comments in the web end very abruptly.

Data supports Lindzen's assertion that the earth has negative rather than positive feedback which resists warming. Abruptly climate changes in the paleoclimatic record require a massive forcing function. The earth's magnetic field drops by a factor of around 7 from it current level during the cold periods. The solar magnetic cycle forcing mechanism is amplified when the geomagnetic field is weak, as the effects move to lower latitudes on the planet.

Try to imagine Canada and a portion of the Northern US states covered with a two mile thick ice sheet. That has happened 22 times. The planet over that period has been cooling cycle by cycle. The deep ocean is now close to freezing.

http://www.sciencedaily.com/releases...0319071426.htm

The results address a major debate in the scientific community, according to Singer and Kaplan, because they seem to undermine a widely held idea that global redistribution of heat through the oceans is the primary mechanism that drove major climate shifts of the past.

The implications of the new work, say the authors of the study, support a different hypothesis: that rapid cooling of the Earth's atmosphere synchronized climate change around the globe during each of the last two glacial epochs.

"Because the Earth is oriented in space in such a way that the hemispheres are out of phase in terms of the amount of solar radiation they receive, it is surprising to find that the climate in the Southern Hemisphere cooled off repeatedly during a period when it received its largest dose of solar radiation," says Singer. "Moreover, this rapid synchronization of atmospheric temperature between the polar hemispheres appears to have occurred during both of the last major ice ages that gripped the Earth."

[William]

The discovery of rapid planetary climate changes was not expected. There was no explanation as to what could be causing this cyclic massive planetary climate changes, prior to the solar magnetic modulation of clouds hypothesis.

There are cosmogenic isotopes which correlate in time (smoking gun evidence) with the timing of the rapid climate changes.

"Sudden climate transitions during the Quaternary"

http://www.esd.ornl.gov/projects/qen/transit.html

Until a few decades ago it was generally thought that all large-scale global and regional climate changes occurred gradually over a timescale of many centuries or millennia, scarcely perceptible during a human lifetime. The tendency of climate to change relatively suddenly has been one of the most surprising outcomes of the study of earth history, specifically the last 150,000 years (e.g., Taylor et al., 1993). Some and possibly most large climate changes (involving, for example, a regional change in mean annual temperature of several degrees Celsius) occurred at most on a timescale of a few centuries, sometimes decades, and perhaps even just a few years.

According to the marine records, the Eemian interglacial (My comment, Eemian is the name for the last interglacial cycle. There has been roughly 22 interglacial/glacial cycles, in the last 1.8 MMyears. The interglacial cycles last approximately 12 kyrs to 15 kyrs, the glacial cycles around 90 kyears.) ended with a rapid cooling event about 110,000 years ago (e.g., Imbrie et al., 1984; Martinson et al., 1987), which also shows up in ice cores and pollen records from across Eurasia. From a relatively high resolution core in the North Atlantic. Adkins et al. (1997) suggested that the final cooling event took less than 400 years, and it might have been much more rapid.

[William]

Checkout figure 5 in the attached paper. CO2 levels are 12 times higher than present 500 million years ago. The sun was not 30% dimmer 500 million years ago.

Note CO2 levels change and there is no corresponding change in planetary temperature.


http://www.aps.org/units/fps/newslet...7/monckton.cfm

[neilzero]

Would you believe 3% dimmer, 500 million years ago? That would make sun light 30% hotter in 5 billion years, if the relationship is linear. Neil

[nauthiz]

Checkout figure 5 in the attached paper.

Check out the disclaimer at the top of the attached paper.

My concerns about that one start right off the bat with figure 1: I don't believe that doing short-term linear regressions on the sampling data is a wise idea. Here's a graph the HadCRUT3 data (which I believe is what was used by the author, though it's hard to be certain because the Hadley center publishes a lot of data sets and the author didn't identify one by name) with trend lines for every set of 8 years. Kind of all over the place, aren't they? Note that Monckton was using a single 6.5 year trend line, so his result is subject to even more instability.


Monckton would have gotten a much more anti-GW looking graph if he had chosen the early '80s, but I guess that would have run a greater risk of people being able to ask him to see the rest of the century.


And my concerns get great enough to make wonder if there's much value in fretting over the rest of the paper by figure 2. That graph, and its accompanying explanation, represent one of the oldest and most noxious canards used by climate change detractors, and frankly it saddens me to see that it isn't dead yet. Hansen made those predictions based on assumptions about how annual greenhouse gas emissions would change in the future. (His purpose was not to make a rock-solid projection, but to encourage discussion in Congress on the issue climate change.) It turned out that the assumptions for none of his three scenarios would match well with what really happened, so drawing much of anything from comparisons of the Hansen predictions to actual temperature data is, to be blunt, completely asinine.

A more interesting (and valid) approach would be to plug the real data back into the model that Hansen used. Sadly, that would not be possible, as the necessary software is no longer available: NASA has continued to maintain and improve its GISS model II and it has long since been refined well beyond the state it was in when Hansen made those predictions two decades ago. Which hits on another really asinine thing about harping on Hansen: the climate change community has long since moved past the state of the art for its 1988 models. Anti-GWers, in poking at the Hansen data, seem to be continually trying (clumsily) to rediscover something that the orthodox climatological community figured out just once, the better part of two decades ago.

[William]

In reply to nauthiz comment: And my concerns get great enough to make wonder if there's much value in fretting over the rest of the paper by figure 2. That graph, and its accompanying explanation, represent one of the oldest and most noxious canards used by climate change detractors, and frankly it saddens me to see that it isn't dead yet. Hansen made those predictions based on assumptions about how annual greenhouse gas emissions would change in the future. (His purpose was not to make a rock-solid projection, but to encourage discussion in Congress on the issue climate change.) It turned out that the assumptions for none of his three scenarios would match well with what really happened, so drawing much of anything from comparisons of the Hansen predictions to actual temperature data is, to be blunt, completely asinine.

I do not understand your comment. Monckton’s paper “Climate Sensitivity Reconsidered” (see attached below) is a summary of fundamental issues with the general climate models and the IPCC's conclusions.

One of Monckton’s points is the planet's oceans have stopped warming. Are you saying that comment is not correct? Why have the oceans stopped warming?

http://www.osdpd.noaa.gov/PSB/EPS/SST/climo.html

I do not understand why a comparison of actual planetary temperature anomalies to predictions is not a logical scientific means to confirm or disprove a hypothesis. What is your concern?

The Intergovernmental Panel on Climate Change (IPCC, 2007) concluded that anthropogenic CO2 emissions probably caused more than half of the “global warming” of the past 50 years and would cause further rapid warming. However, global mean surface temperature has not risen since 1998 and may have fallen since late 2001. The present analysis suggests that the failure of the IPCC’s models to predict this and many other climatic phenomena arises from defects in its evaluation of the three factors whose product is climate sensitivity:

1. Radiative forcing ΔF;
2. The no-feedbacks climate sensitivity parameter κ; and
3. The feedback multiplier ƒ.

http://www.aps.org/units/fps/newslet...7/monckton.cfm

[nauthiz]

One of Monckton’s points is the planet's oceans have stopped warming. Are you saying that comment is not correct? Why have the oceans stopped warming?

The downward ocean surface temperature trend has been happening for an even shorter amount of time than the downward global mean surface temperature trend, so I have the same problem with making a big deal out of it.

I do not understand why a comparison of actual planetary temperature anomalies to predictions is not a logical scientific means to confirm or disprove a hypothesis. What is your concern?

I have no problem with comparing models to reality - it's a necessary part of the process. What I do have a problem with is comparing models to reality in a way that is fundamentally wrong: If you take incorrect data and feed it into a model, then of course you shouldn't expect it to line up with reality. Mathematically (the models in question are mathematical objects), it be the same as criticizing arithmetic on the basis that 2+2=4 but 5+7=12. Yet this is exactly what happens when people compare the Hansen projections with actual temperature records.

[William]

In reply to nauthiz's comment: Research which calls the Douglass paper's results into question has come out since then. Basically, the authors glossed over known accuracy problems in the instrumentation that produced their data, and these problems make it hard to draw any reliable conclusions from the tropical troposphere data.

The science appears to still be unresolved. Those who do not support the findings of Douglas et al. state that the discrepancy might be due to a problem with the general climate models or perhaps could be due to an instrumentation bias (See the quote below from Realclimate.)

As the mid-stratosphere appears to have cooled rather than warmed, if the problem is not with instruments but with the reason why the planet has recently warmed, (say for example the warming was due to a reduction in planetary clouds due to electroscavenging, rather than to the GHG mechanism), then a sudden increase in planetary clouds would cause the planet to abruptly cool and should settle the scientific issue.

My problem with the mechanisms in general, is how to explain the past rapid climate changes with the insolation theory mechanisms. The orbital insolation changes are gradual. They are not capable of cooling the planet (Northern and Southern Hemisphere) by 2C in less than decade.

Also as I stated I have a problem with simple correlation of insolation changes that cannot possibly based on the magnitude of the insolation change in question have cause the observed cyclic change of the planet's temperature. For example, the insolation affect on planetary temperature due to changes in the eccentricity of the earth's orbit is the smallest of the three orbital changes, yet it now drives the glacial/interglacial cycle.

It is as if a small child is blamed for a few thousand houses that were demolished due to a hurricane. Obviously the small child is physically not capable of what is observed. Think of a two mile thick ice sheet that covers all of Canada and a portion of the Northern US States for 80kyrs. This is a major climatic cycle. It is difficult for anyone to imagine that this cycle has occurred 22 times in the past.

My disbelief, concerning the insolation mechanism, is shared by paleoclimatic specialists.

Thomas Cronin, from his text book "Principles of Paleoclimatology" writes:

"Eccentricity changes introduce such small total changes in insolation, relative to those from precession and obliquity, that the degree to which eccentricity alters earth's climate has been a troublesome aspect of orbital theory. This is the case especially for the past 600 kyrs when the 100 kyr cycle was evident. Translating small insolation changes into huge glacial-interglacial climatic swings characteristic of the earth's recent past has been difficult for paleoclimatic modellers."...

"A reduction in elliptical orbits from its present value of 0.17 to 0.04 translates into a very small net change in total solar radiation reaching the earth's upper atmosphere - only about 0.1% of total insolation, or about 0.5 W/m2. A change of this magnitude would cause a change in mean annual global temperature of only a few tens of a degree Celsius."...

If you look at the actual magnitude of the eccentricity insolation forcing as compared to precession and obliquity it is seems that there is another major forcing function that is causing the change.

In addition as noted above, Kaplan's very recent finding that the Southern and Northern hemispheres warm and cool in synchronism proves the forcing is not eccentricity or the other insolation changes, as the effect of the insolation changes is 180 degrees out of phase, comparing Northern to Southern Hemisphere.

Kaplan's findings is supported by other research that has shown that for two cases the abrupt change from glacial to interglacial occurred before orbital insolation forcing was at its maximum.

First off, Lanzante and Free do an excellent job in really pinning down the biases (compared to satellites and models) of the standard homogenised radiosonde networks (RATPAC2 and HadAT2). These biases undoubtedly exist and the issue is to work out whether they are due to instrumental problems, sampling issues, errors in model physics or errors in model forcings (or all of the above!). In the global mean, there isn't much of an issue for the mid-troposphere - the models and data track each other when you expect they would (the long term trends or after volcanoes, and don't where you expect them not to, such as during La Niña/El Niño events which occur at different times in models and observations). Similarly the lower stratospheric trends and variability is reasonably matched except for the post-Pinatubo period where the sondes cool uniformly more than the models - possibly due to underestimation of the stratospheric ozone trend. However, the big discrepancies are in the tropics.

[dmr81]

The discovery of rapid planetary climate changes was not expected. There was no explanation as to what could be causing this cyclic massive planetary climate changes, prior to the solar magnetic modulation of clouds hypothesis.

There are cosmogenic isotopes which correlate in time (smoking gun evidence) with the timing of the rapid climate changes.

"Sudden climate transitions during the Quaternary"

http://www.esd.ornl.gov/projects/qen/transit.html

That paper does not give any support to your ATM idea. It does not mention clouds, cosmic rays or the sun's magnetic field.

[dmr81]

http://www.aps.org/units/fps/newslet...7/monckton.cfm

Lord Monckton is not a climate scientist, nor any kind of scientist. "He was educated at Harrow School, Churchill College, Cambridge where he read classics and University College, Cardiff, where he obtained a diploma in journalism." (source).

A detailed list of the errors in Monckton's July 2008 Physics and Society article.

[dmr81]

My problem with the mechanisms in general, is how to explain the past rapid climate changes with the insolation theory mechanisms. The orbital insolation changes are gradual. They are not capable of cooling the planet (Northern and Southern Hemisphere) by 2C in less than decade.

If you'd bothered to read the paper to which you linked above you might have a clearer idea. Here are the section headings that show the feedback mechanisms they considered...

III. The mechanisms behind sudden climate transitions.

It is still unclear how the climate on a regional or even global scale can change as rapidly as present evidence suggests. It appears that the climate system is more delicately balanced than had previously been thought, linked by a cascade of powerful mechanisms that can amplify a small initial change into a much larger shift in temperature and aridity (e.g., Rind and Overpeck, 1993). At present, the thinking of climatologists tends to emphasize several key components:

III.1. North Atlantic circulation as a trigger or an amplifier in rapid climate changes.
II.2 Carbon dioxide and methane concentration as a feedback in sudden changes.
III.3 Surface reflectivity (albedo) of ice, snow and vegetation.
III.4 Water vapour as a feedback in sudden changes.
III.5. Dust and particulates as a feedback in sudden changes.

http://www.esd.ornl.gov/projects/qen/transit.html

[William]

In reply to dmr81's comment:

Let's address each of your miss-understandings.

First the North Atlantic drift current myth.

This paper by Seager et al. quantifies why a sudden stoppage of the North Atlantic drift would have a minor effect on North Atlantic climate.

The ocean current hypothesis was never quantified. i.e. A stoppage of the current does not have the power to create the desired effect. Wally Broecker started the myth.

Science is based on data and analysis.

http://www.ldeo.columbia.edu/res/div...al_QJ_2002.pdf

Incidentally the North Atlantic drift current is currently reduced by 30%, no drastic effects.

In addition to the problem that North Atlantic drift current does not have the capability to have the cool the entire planet by 2C there is no mechanism to abruptly start and stop the North Atlantic drift current cyclically.

Bond found the climate cycles occurred with a periodicity of 1450 years, in addition to the 2400 cycle.

Each of the climate cycles has cosmogenic isotopes that occur at the same time. That is a fact that supports the solar modulation of cloud hypothesis.

In conclusion,while OHT warms winters on both sides of the North Atlantic Ocean by a few degC, the much larger temperature difference across the ocean, and that between the maritime areas of north-western Europe and western North America, are explained by the interaction between the atmospheric circulation and seasonal storage and release of heat by the ocean.

[William]

Atmospheric dust increases by a factor of 10 during the cold periods, as when the planet is very, very, cold there is less precipitation and there is vast desertification. Almost a 1/3 of the Amazon rainforest changed to savannas type grass lands during the cold periods.

Paleo climatologists do not have an explanation for what causes the abrupt climate changes.

Initial evidence from the GRIP ice core evidence (Dansgaard et al., 1993; Taylor et al. 1993) indicated that the Eemian was punctuated by many short-lived cold events, as shown by variations in electrical conductivity (a proxy for windblown dust, with more dust indicating colder, more arid conditions) and stable oxygen isotopes (a proxy for air temperature) of the ice were used by these workers infer the climatic conditions during the Eemian. The cold events seemed to last a few thousand years, and the magnitude of cooling was similar to the difference between glacial and interglacial conditions; a very dramatic contrast in climate. Furthermore, the shifts between these warm and cold periods seemed to be extremely rapid, possibly occurring over a few decades or less.

The following is an excerpt from Broecker’s famous Angry Beast article (see attached link for details) in which he discussions macroclimate models and extreme climate changes:

http://www.soest.hawaii.edu/GG/FACUL...SA%20Today.pdf

“Models to the Rescue?”

“…No one understands what is required to cool Greenland by 16C and the tropics by 4 +/-1C, to lower the mountain snowlines by 900m, to create an ice sheet covering much of North America, to reduce…CO2 by 30%, or to raise the dust rain… by an order of magnitude. If these changes were not documented in the climate record, they would never have entered the minds of the climate dynamics community....


Models that purportedly simulate glacial climates do so only because key boundary conditions are prescribed (the size and elevation of ice sheets, sea ice extent, sea surface temperature, CO2 content, etc”

The current climate models do not explain and cannot reproduce the sever and abrupt climate changes in the proxy climatic record.

Comments:
1) In the Angry Beast article Broecker postulates that the Younger Dryas (Youger Dryas is the name for the sever cooling event that occur during the start of this interglacial) was caused by a fresh water pulse, from Lake Agassiz (Lake Agassiz was a massive glacial lake in the Province of Manitoba) Subsequent data has shown that the fresh water pulse hypothesis is likely not correct, as the fresh water pulse occurred a 1000 years before the Younger Dryas. See attached paper below for the data and another hypothesis.

2) An alternative hypothesis to Broecker’s non-linear knife edge hypothesis (Small natural or anthropogenic changes can force the macroclimate from one mode to another mode and hence create the massive ice sheets and so forth.) is the hypothesis there is a massive semi-periodic external forcing, that forces the macroclimate from one mode to another.

Reduced solar activity as a trigger for the start of the Younger Dryas?

http://www.geo.vu.nl/~renh/pdf/Renssen-etal-QI-2000.pdf

As the paper notes besides Seager's analysis which indicates the THC does not have the power to plunge the planet back into an ice age, the trigger which is hypothesized to have turned the thermohaline circulation (THC) off the release of water from Lake Agassiz is 1000 years before the start of Younger Dryas cooling.

Although acceptance of the shallower THC hypothesis may explain part of the geological evidence for the YD, the important question what the trigger for the THC weakening exactly was, remains to be answered. The timing of the meltwater pulses, being the proposed source of perturbation, causes a problem. The main late glacial meltwater pulse found by Fairbanks (1989) is dated at 14 ka cal BP, thus at least 1000 years before the start of the YD (Bard et al., 1996).

[William]

As referenced in my above comment, there is this recent finding that supports global synchronous, climate change.

A solar modulation of cloud mechanism would effect both hemispheres. The North Atlantic Drift current would only effect one hemisphere and Singer's et al's paper quantifies that complete stoppage of the North Atlantic drift current would only cool winter European temperatures by a few degrees Celsius and would have no effect on European summer temperatures.

http://www.nsf.gov/news/news_summ.js...100348&org=ATM

(This data and analysis) … address a major debate in the scientific community, according to Singer and Kaplan, because they seem to undermine a widely held idea that global redistribution of heat through the oceans is the primary mechanism that drove major climate shifts of the past.

The implications of the new work, say the authors of the study, support a different hypothesis: that rapid cooling of the Earth's atmosphere (my comment: Or some other forcing function that can change temperature in both hemisphere.) synchronized climate change around the globe during each of the last two glacial epochs.

"Because the Earth is oriented in space in such a way that the hemispheres are out of phase in terms of the amount of solar radiation they receive, it is surprising to find that the climate in the Southern Hemisphere cooled off repeatedly during a period when it received its largest dose of solar radiation," says Singer. "Moreover, this rapid synchronization of atmospheric temperature between the polar hemispheres appears to have occurred during both of the last major ice ages that gripped the Earth."

Here is a link to another paper by the same authors that provides data which supports synchronous climatic change in the current interglacial period.

http://www.geology.wisc.edu/~davem/abstracts/05-2.pdf

[William]

One of Monckton’s points is the planet's oceans have stopped warming. Are you saying that comment is not correct? Why have the oceans stopped warming?

http://www.osdpd.noaa.gov/PSB/EPS/SST/climo.html

[dmr81]

Let's address each of your miss-understandings.

I did not offer my own opinion. I quoted from the paper to which you linked. You claimed that the paper supported your ATM idea about cloud formation. Now that I have shown that it didn't, you are claiming that it is wrong.

Each of the climate cycles has cosmogenic isotopes that occur at the same time. That is a fact that supports the solar modulation of cloud hypothesis.

You still haven't provided a shred of evidence to support this claim. All you've done is insinuate that certain papers support it when in fact they make no mention of it.

[dmr81]

One of Monckton’s points is the planet's oceans have stopped warming. Are you saying that comment is not correct? Why have the oceans stopped warming?

http://www.osdpd.noaa.gov/PSB/EPS/SST/climo.html

This has already been answered by lomiller1 here and here, and by the article to which I linked above.

[William]

http://www.americanscientist.org/iss...mild-climate/1

This is a more accessable version of Seager's paper, written for Scientific America, on why the Gulf Stream is not responsible for Europe's warm winters or the Bond climatic cycles.

The jet stream as it moves west to east over the Rockies due to Coriolis force moved down pulling cold Canadian air into the US. Counteracting forces cause the jet stream to move from South to North as it crosses the Atlantic bring warmer air to the UK and Europe.

Those large fixed air patterns are called Rossby waves.

http://en.wikipedia.org/wiki/Rossby_wave

[lomiller1]

One of Monckton’s points is the planet's oceans have stopped warming. Are you saying that comment is not correct? Why have the oceans stopped warming?

http://www.osdpd.noaa.gov/PSB/EPS/SST/climo.html

Monkton is a JOURNALIST he has credentials whatsoever in physics or climate science.

There is some data suggesting ocean heat content hasn’t increased in the last 2 years, but no one has attributed a cause to that and no one has even ascertained if it’s anything more then natural variation. Ocean heat content is less susceptible to year to year variation then atmospheric temperature, but it is not immune, and it’s been well documented that ocean heat content has been increasing for 5+ decades.

http://www.nature.com/nature/journal...ture07080.html

It’s behind a paywall but you can see the results courtesy of realclimate

http://www.realclimate.org/images/ohc_domingues.jpg

http://www.realclimate.org/index.php...ent-revisions/


Other then simple year to year variation, some possible reasons ocean heat content didn’t rise include more heat going into the deep ocean and more heat going into melting ice.

[HenrikOlsen]

and more heat going into melting ice.

The latter driven by the increased air temperatures causing faster glaciers, so there's more (old) ice being pushed into the oceans.

[William]

Have there been warm periods in the past? Yes.

http://www.esd.ornl.gov/projects/qen/transit.html

II.2.a. Interstadials.
Sudden and short-lived warm events occurred many times during the generally colder conditions that prevailed between 110,000 and 10,000 years ago (isotope Stages 2-5.4). First picked up as brief influxes of warm climate plants and insects into the glacial tundra zone of northern Europe, they are known as 'interstadials' to distinguish them from the cold phases or 'stadials' (Lowe & Walker 1984). The interstadials show up strongly in the Greenland ice core records. Between 115,000 and 14,000 years ago, 24 of these warm events have been recognized in the Greenland ice cores (where they are called 'Dansgaard-Oeschger events'; e.g., Bond et al., 1993; Bond and Lotti, 1995). Many lesser warming events have also been seen in the ice core records (e.g., Dansgaard et al., 1993; Taylor et al., 1993; 1997; Mayewski et al., 1997) but have not yet been recognized elsewhere. Short-lived and/or moist warm phases, coeval with interstadials, appear in the eastern Pacific (Behl and Kennett 1996), western Siberia, the Arabian Sea (Schulz et al., 1998) …

…Ocean Drilling Program Leg 169S, Saanich Inlet, British Coumbia, Canada). Ice core and ocean data suggest that interstadials both began and ended suddenly, though in general the 'jump' in climate at the start of an interstadial was followed by a more gradual decline involving a stepwise series of smaller cooling events and often a fairly large terminal cooling event which returned conditions to the colder 'glacial' state (e.g., Rasmussen et al., 1997). From the ice core evidence from Greenland, warming into each interstadial occurred over a few decades or less, and the overall duration of some of these warm phases may have been just a few decades, while others vary in length from a few centuries to nearly two thousand years (e.g, Mayewski et al., 1997).

Is cause of the periodic warm periods and the extreme abrupt shifts to cold periods due to the THC? No. See Seager's article in Scientific America and his paper.

http://www.bautforum.com/general-sci...ml#post1333865

What are the implications of Kaplan's findings of simultaneous cooling and warming of Northern and Southern Hemispheres?

http://www.bautforum.com/general-sci...ml#post1332080

[William]

The Milankovitch insolation mechanism does not explain the observations.

There is clearly a very large first order forcing function that is the trigger for what is observed. As there are cosmogenic isotopes that coincide in time with the abrupt cold events, it seems likely that a solar magnetic field change is driving the change.

As shown above ocean currents (THC) are not the forcing function.

Likewise as the Northern and Southern hemispheres are simultaneously affected and the change is abrupt, insolation due to orbital changes is not the forcing function.

The 41 kyr world: Milankovitch’s other unsolved mystery

All serious students of Earth’s climate history have heard of the ‘‘100 kyr problem’’ of Milankovitch orbital theory, namely the lack of an obvious explanation of the dominant approx. 100 kyr periodicity in climate records of the last 800,000 years. However, few have considered an equally perplexing characteristic of Earth’s climate, one that similarlydefies simple physical explanation yet dominates the Earth’s recent geologic record. We call this the ‘‘Milankovitch 41 kyr problem.’’

http://maureenraymo.com/2003_Raymo+Nisancioglu.pdf

http://www.sciencedirect.com/science...664dd77c4d73e0

[William]

In reply to HenrikOlsen and lomiller1,

I accept the data and analysis that shows the planet has warmed in the last 30 years. New data and analysis, however, directly challenges the assertion that the reason why the planet warmed was GHG.

There is data and analysis that indicates that GHG forcing has been over estimated by roughly a factor of two to three times. There is also data and analysis that shows the feedback mechanisms that are asserted to amplify any planetary warming have been over estimated.

The general climate models predict a warming of the mid-troposphere due to the CO2 greenhouse effect that is roughly two to three times greater than what is observed (Douglas et al 2007).

http://www.bautforum.com/general-sci...ml#post1331737

The following is a paper by Lindzen that explains the greenhouse mechanism and the observations.

http://cfa-www.harvard.edu/~wsoon/Ar...rm-lindz07.pdf

“Taking Greenhouse Warming Seriously” R. Lindzen

Using basic theory, modeling results and observations, we can reasonably bound the anthropogenic contributions to surface warming since 1979 to a third of the observed warming, leading to a climate sensitivity too small to offer any significant measure of alarm assuming current observed surface and tropospheric trends and model depictions of greenhouse warming are correct.

http://en.wikipedia.org/wiki/Troposphere

Following common meteorological practice, height is replaced by pressure level. Pressure decreases approximately exponentially with height. 100 hPa (hector Pascals) corresponds roughly to 16 km; 200 hPa to 12 km; 500 hPa to 6 km; and 1000 hPa to the surface. What we see is that warming is strongly peaked in the tropical troposphere near the τ=1 level (which actually differs from model to model because the amount of water vapor differs among the models). Roughly speaking, the warming at τ=1 in the tropics is from more than twice to about three times larger than near the surface regardless of the sensitivity of the particular model. This is, in fact, the signature (or fingerprint) of greenhouse warming. Stated somewhat differently, if we observe warming in the tropical upper troposphere, then the greenhouse contribution to warming at the surface should be between less than half and one third the warming seen in the upper troposphere.

Fortunately, we have been measuring atmospheric temperatures with balloons since at least the 1960's and with microwave satellite sensors since 1979. Initially, the satellite and balloon data were showing insignificant temperature change for the tropical troposphere, while surface data was showing a warming trend of about 0.13 degrees Centigrade/decade. This gave rise to deep concern resulting in studies by both the National Research Council (2000) and the US Climate Change Science Program (2006) where strong attempts were made to find warming in the troposphere. It is now believed that there is indeed warming in the atmosphere. Figure 5 is the most recent depiction of the trends based balloon data from the United Kingdom’s Hadley Centre and incorporating the adjustments suggested by the above studies. We see that the trend in the troposphere does have a relative maximum near 300 hPa of about .1 degree C per decade, and judging from the results in Figure 5, this should be associated with a surface trend of between 0.033 and somewhat less than 0.05 degrees per decade. Contrary to the iconic statement of the latest IPCC Summary for Policymakers, this is only on the order of a third of the observed trend at the surface, and suggests a warming of about 0.4 degrees over a century. It should be added that this is a bound more than an estimate.

[dmr81]

The general climate models predict a warming of the mid-troposphere due to the CO2 greenhouse effect that is roughly two to three times greater than what is observed (Douglas et al 2007).

This was already answered by nauthiz when you brought it up a couple of posts ago. Here is the relevant link again:
http://www.realclimate.org/index.php...ropopshere-ii/

The following is a paper by Lindzen

Same issue again:
http://www.realclimate.org/index.php...#comment-98364

Both these belong in ATM, not in this forum.

[William]

In reply to dmr81

Originally Posted by William View Post: The general climate models predict a warming of the mid-troposphere due to the CO2 greenhouse effect that is roughly two to three times greater than what is observed (Douglas et al 2007).

Quote: Originally Posted by dmr81 View Post: This was already answered by nauthiz when you brought it up a couple of posts ago. Here is the relevant link again:
http://www.realclimate.org/index.php...ropopshere-ii/

dmr81, The link you provide notes something must be in correct with the General Climate Models. Douglas et al published a subsequent paper that shows the 40 years of data does show the mid troposphere in equatorial regions has not warmed.

The fact that the mid troposphere in equatorial regions has not warmed, in accordance with the General Climate models, indicates something is fundamentally in correct with the General Climate models. The problem is not 40 years of mid tropospheric temperature data is in correct.

The blog you linked to ignores data and published papers that does not support their viewpoint.

I note that you and the blog you linked to have no comment concerning the disproved myth that the changes to the thermalhaline conveyor (THC) can cause abrupt warming and cooling of the planet. See my link above to Seager's paper that was published in American Scientist and a speciality periodical.

http://www.bautforum.com/general-sci...ml#post1333865

Note the planet has cyclically abruptly warmed and cooled in the past. What is forcing the planet's temperature? Published papers show cosmogenic isotopes changes are concurrent in time with the abrupt warming and cooling of the planet. Published papers show planetary cloud cover is modulated by changes in galactic cosmic rays GCR when the electroscavenging mechanism is taken into account.

But no need to argue. The sun is heading to a deep solar magnetic minimum so we should see a change in planetary temperature this winter. (Planet will start to abruptly cool.) But is it ATM to make that statement also?

Any comments concerning the Milankovitch insolation myth? What is causing the 100 kyr glacial/interglacial cycle? Why was it a 41 kyr cycle in the past? It is obvious the solar magnetic cycle is the mysterious forcing function. Particularly as there are 40 published papers all supporting the solar modulation of clouds mechanism.

http://www.bautforum.com/general-sci...ml#post1336811

The problem is not a lack of scientific data or published papers to support the argument I am presenting above. I am presenting a logical argument that is supported by data and published papers. The viewpoint I am presenting is the authors of the papers not mine.

Name calling "ATM", shows that you are not reading the linked papers. You are not thinking about the 22 glacial/interglacial cycles that have happened in the past.

The following is a comparison of the Greenland Ice Temperatures to the Antarctic Ice Temperatures for the last 140 kyrs.

The warm interstadial periods are evident in the Greenland data and are followed by a return to the very cold glacial period. Note the abrupt end to the last interglacial period the “Eemian” Interglacial. (P.S. The current warm interglacial period which is called the "Holocene Interglacial period is shown in an expanded scale. Interglacial periods have in the past ended abruptly.)

Comment: The Antarctic ice sheet proxy data smooths out the abrupt planetary temperature changes due to something paleo climatologists call the "Polar See-Saw Effect" where when clouds cool the planet, the Antarctic continent warms, rather than cools, as the ice albedo is greater than clouds so there is a net warming, when there is more clouds over the Antarctic ice sheet. The Antarctic continent was cooled over the last 30 years as the majority of the warming of the planet is due to a reduction in planetary cloud cover not GHG.

[William]

The Antarctic has cooled while the rest of the planet has warmed in the last 30 years. Svensmark has this explanation for what is known as the polar see-saw is that solar changes in the 20th century have caused a reduction in planetary cloud cover.

The albedo of the Antarctic ice sheet is so high (the ice reflects more sunlight than clouds) so the net affect of a reduction in planetary cloud cover is an increase in Antarctic ice sheet temperature.

Svensmark in the following paper presents an analysis of NASA satellite cloud data that supports the cloud mechanism. In addition he compares Greenland ice sheet temperatures at different depths in the ice sheet with Antarctic Ice sheet temperatures at different depths, to prove that when the Greenland icesheet warms the Antarctic ice has cooled, over the last 6000 years.

Comment: The ice sheet is an insulator, so it locks in the relative temperature when the ice formed in the ice sheet. It takes thousand of years for the locked in temperature to equalize. Before the in ice sheet temperatures equalize, they can be used to for relatively short temperature planetary temperature analyze.

As the sun is spotless and there will be likely a very, low solar magnetic cycle, there should be (If the solar magnetic cloud hypothesis, is correct.) an increase in planetary cloud cover and an temporary increase in Antarctic ice sheet temperature. As the planet continues to cool (assuming a Maunder minimum rather than a cycle slow down), the Antarctic will also cool, as it pulls heat from the surround ocean.

The following is from Svensmark’s paper:

http://arxiv.org/abs/physics/0612145v1

“The Antarctic climate anomaly and galactic cosmic rays” by Henrik Svensmark

Contradictory trends in temperature in Antarctica and the rest of the world, which are evident on timescales from millennia to decades, provide a strong clue to what drives climate change. The southern continent is distinguished by its isolation and by its unusual response to changes in cloud cover. While the rest of the global surface is (on balance) cooled by clouds, they have a warming effect on high-albedo snowfields[5, 6, 7, 8, 9, 10]. NASA’s Earth Radiation Budget Experiment (ERBE) [11, 12] provided valuable data on the effects of clouds at different latitudes. They can be interpreted to show that, if changes in cloudiness drive climate change, the anomalous behavior of Antarctica is predictable Borehole temperatures in the ice sheets spanning the past 6000 years show Antarctica repeatedly warming when Greenland cooled, and vice versa (Fig. 1) [13, 14].

[dmr81]

The link you provide notes something must be in correct with the General Climate Models.

No it does not. It says "The new analysis adds to the growing body of evidence suggesting that these discrepancies are most likely the result of inaccuracies in the observed temperature record rather than fundamental model errors."

The blog you linked to ignores data and published papers that does not support their viewpoint.

No it does not. It specifically addresses the paper to which you referred.

I note that you and the blog you linked to have no comment concerning the disproved myth that the changes to the thermalhaline conveyor (THC) can cause abrupt warming and cooling of the planet.

Straw man. I have not seen anyone claim that it did. The only mention I recall on this thread was in one of the papers to which you linked, which analyzed its possible function as a feedback mechanism.

Note the planet has cyclically abruptly warmed and cooled in the past.

Nobody is disputing that. I am disputing the fallacious conclusion that you have drawn from that premise: that since there have been natural changes in the past all changes must be natural.

What is forcing the planet's temperature?

There are many factors involved. See the IPCC report for details. A chart summarizing them is available here.

Published papers show planetary cloud cover is modulated by changes in galactic cosmic rays GCR when the electroscavenging mechanism is taken into account.

Asked & Answered

The sun is heading to a deep solar magnetic minimum

Speculation.

so we should see a change in planetary temperature this winter. (Planet will start to abruptly cool.) But is it ATM to make that statement also?

Yes it is ATM. The mainstream view is that even if there were an extended minimum it would not outweigh the greenhouse warming.

Any comments concerning the Milankovitch insolation myth?

Asked & Answered.

It is obvious the solar magnetic cycle is the mysterious forcing function. Particularly as there are 40 published papers all supporting the solar modulation of clouds mechanism.

Asked & Answered

Name calling "ATM",

It is not "name calling" to call something ATM when it is ATM. I have already asked you to provide a citation from the IPCC endorsing your ATM idea. Provide it or cease to deny that it is ATM.

shows that you are not reading the linked papers.

As I have demonstrated, you are the one who is not reading the papers to which you are linking. Either that or you are just hoping that we don't, since they do not provide the support you claim for your ATM idea.

You are not thinking about the 22 glacial/interglacial cycles that have happened in the past.

Asked & Answered.

The Antarctic continent was cooled over the last 30 years

http://environment.newscientist.com/...change/dn11648

as the majority of the warming of the planet is due to a reduction in planetary cloud cover

Another wildly ATM claim without a shred of evidence.