Reader “Markx” writes in Tips and Notes on a paper I hadn’t noticed before (because it was published before WUWT was born). Of course it only works if CO2 has a long residence time and/or our elevated emission levels continue. We need at least 3x more CO2 to pull off the delay.
A movable trigger: Fossil fuel CO2 and the onset of the next glaciation. David Archer and Andrey Ganopolski
Published in G3 Geochemistry Geophysics Geosystems Research Letter Volume 6, Number5 5 May 2005
Abstract:
The initiation of northern hemisphere ice sheets in the last 800 kyr appears to be closely controlled by minima in summer insolation forcing at 65N. Beginning from an initial typical interglacial pCO2 of 280 ppm, the CLIMBER-2 model initiates an ice sheet in the Northern Hemisphere when insolation drops 0.7 s (standard deviation) or 15 W/m2 below the mean. This same value is required to explain the history of climate using an orbitally driven conceptual model based on insolation and ice volume thresholds (Paillard, 1998). When the initial baseline pCO2 is raised in CLIMBER-2, a deeper minimum in summertime insolation is required to nucleate an ice sheet. Carbon cycle models indicate that 25% of CO2 from fossil fuel combustion will remain in the atmosphere for thousands of years, and 7% will remain beyond one hundred thousand years (Archer, 2005). We predict that a carbon release from fossil fuels or methane hydrate deposits of 5000 Gton C could prevent glaciation for the next 500,000 years, until after not one but two 400 kyr cycle eccentricity minima. The duration and intensity of the projected interglacial period are longer than have been seen in the last 2.6 million years.
Some excerpts:
“Models require some amplifying feedback, from sea ice … or the terrestrial biosphere ….to nucleate on the basis of insolation forcing, but insolation is always the primary driver.”
and
An anthropogenic release of 300 Gton C (as we have already done) has a relatively small impact on future climate evolution, postponing the next glacial termination 140 kyr from now by one precession cycle.
Release of 1000 Gton C … is enough to decisively prevent glaciation in the next few thousand years, and given the long atmospheric lifetime of CO2, to prevent glaciation until 130 kyr from now.
If the anthropogenic carbon release is 5000 Gton or more….[…]… The model predicts the end of the glacial cycles, with stability of the interglacial for at least the next half million years…
Figure 3. Effect of fossil fuel CO2 on the future evolution of climate. Green represents natural evolution, blue represents the results of anthropogenic release of 300 Gton C, orange is 1000 Gton C, and red is 5000 Gton C. (a) Past and future pCO2 of the atmosphere. Past history is from the Vostok ice core [Petit et al., 1999], and future anthropogenic perturbations are from a carbon cycle model [Archer, 2005]. (b) June insolation at 65N latitude, normalized and expressed in s units. 1 s equals about 20 W m2. Green, blue, orange, and red lines are values of the critical insolation i0 that triggers glacial inception. The i0 values are capped at 3 s to avoid extrapolating beyond model results in Figure 3; in practice, this affects only the 5000 Gton C scenario for about 15 kyr. (c) Interglacial periods of the model. (d) Global mean temperature estimates.
Not having mile thick ice sheets crush northern hemisphere cities is a good thing, don’t you think?
Full PDF here: http://geosci.uchicago.edu/~archer/reprints/archer.2005.trigger.pdf
Sorry — don’t believe it. Only a couple thousand ppm CO2 could have enough effect, if then.
“..seen in the last 2.6 million years”? Seen by whom?
I have read that the only way to get us out of the Ice Age, in which we currently live and have so lived for that last 2.5 million years, is to remove the Isthmus of Panama. CO2 does not come into play with this equation at all.
….to be closely controlled by minima….
henry says
those are all pipe dreams.
not a chance.
not even the recent warming was due to CO2
http://wattsupwiththat.com/2013/04/25/dana-nuccitelli-misleads-and-misinforms-in-his-first-blog-post-at-the-guardian/#comment-1289402
It’s a nice dream anyway, the same one Svante Arrhenius had.
No chance! We haven’t seen the end of the ice-ages.
In his book, “Coal Trains of Death” Hansen says that the output from a single chlorofluorocarbon plant is enough to prevent an ice age.
That could be wishful thinking.
http://www.geocraft.com/WVFossils/PageMill_Images/image277.gif
“Not having mile thick ice sheets crush northern hemisphere cities is a good thing, don’t you think?”
Think of all the shoveling we would save…
While it is refreshing to read someone at least trying to take an objective look at climate change rather that screaming about catastrophe, I don’t put any more faith in this model than I do the IPCC’s various models and only slightly more than a sheep’s entrails.
We are a long way yet from understanding what is going on to an extent that allows us to model climate. There are waaayy too many exceptios probing the regnums.
I vaguely recall that during the late Ordovician Co2 was over 4,000 parts per million. (Today 400ppm).
I vaguely recall during the late Ordovician there was an ice age.
I vaguely recall that Co2 remained at over 3,000 ppm throughout the glaciation.
C02 is a magical gas. 😉
The length of the Holocene without any CO2 in the graph above seems unusually long. Is this reasonable? Doesn’t the paleo record show that inter-glacials have all been quite short? In the absence of CO2, why expect this time be different?
It seems more likely that the prediction of the lengthy, non CO2 interglacial is wishful thinking, in support of limiting CO2 production for political and economic advantage. If we are on the edge of slipping into the next ice age, then CO2 may provide the only hope for the future of many of the cities and peoples of the world.
Otherwise, we are left with the 1950’s alternative. Building thousands of nuclear power plants to heat the oceans, and/or thousands of gigantic solar reflectors in space to warm the land.
oh good grief…this was 8 years ago
…science has progressed since then
Now we know that it causes wet/dry, warm/cold, snow/rain, freeze/heat, drought/flood, and earthquakes………….
It’s funny how our dangerous level of co2 at well above the safe limit of 350ppm could not prevent the 15 year global temperature standstill (slight 10 years of cooling), but at higher levels is sufficient to prevent another ice age.
10 times more co2 failed to do this.
The model appears to be based on a climatic sensitivity to CO2 that is typical of the beliefs of the warmist fraction.
It is thus quite possible that the CO2 will have as trivial an effect on the next glacial as it is having this past decade (and more) on global average temperatures.
I think the next bond event will probably start the next glaciation. Its due soon geologically speaking so maybe fun for all.
CO2 will not stop a glaciation because as the oceans cool they will suck up CO2 from the atmosphere.
The problem with the CO2 warming hypothesis is that if makes Ice Ages and Interglacials impossible. We know that the oceans release CO2 as they warm. Thus Interglacials make the next Ice Age impossible. We know that oceans absorb CO2 as they cool. Thus Ice Ages make the next Interglacial impossible.
However, we know that Ice Ages and Interglacials happen regularly, with only a very slight change in solar energy reaching the earth due to orbital mechaniscs. So, either the paleo records are wrong, or the CO2 warming hypothesis is wrong.
Gosh it appears that people have not noticed that we are near the end of the present interglacial and that it has been cooling for around 4,000 years now.
Here once again are some references to charts which are based on empirically based published science papers using actual and credible proxies.This is from Chapter 8-10 of his book and linked to his website:
http://theinconvenientskeptic.com/chapters-8-10/
Go there and see that this interglacial period is almost over and called the Autumn phase at this point of history.
Jimbo says:
April 27, 2013 at 7:22 am
———————————————-
And from the same site
http://www.geocraft.com/WVFossils/PageMill_Images/image354.gif
IF the plant stomata proxies are more accurate than the ice core ones it`s possible co2 levels from previous interglacials were a lot higher than indicated , then it means the rating of the glacial delaying effect from CO2 would drop from “BB gun Vs charging elephant” to “pop gun” rating .
Admit it, you just want to ruin the shovel and snow plow industry!
Byron says:
April 27, 2013 at 8:01 am
IF the plant stomata proxies are more accurate than the ice core ones it`s possible co2 levels from previous interglacials were a lot higher than indicated
=========
that would explain the inconsistency between glacial cycles and CO2 levels. it would indicate that today’s CO2 levels are consistent with past CO2 levels during interglacials, and that warming, not SUV’s, is the cause of CO2. Or, that CO2 is the result of widespread land use change over the past 100 years.
The claims in the paper are completely preposterous. First, even if the CO2 doubling caused (sensitivity) of 2 Celsius degrees, one would need four doublings to get 8 °C to neutralize an ice age – sixteen times larger concentrations of CO2.
But this mistake is negligible relatively to the residence time. We will probably run out of – or stop using fossil fuels – within 300 years or much less. Within two more centuries, a vast majority of the excess CO2 will be reabsorbed again. There’s no way how we could affect temperatures in the future that is as distant as 5,000 years – first moment when a credible sign of a new ice age might potentially occur.
Moreover, the true new local minimum ice age will arrive in 60,000 years or so and that’s much further:
http://motls.blogspot.com/2012/03/next-peak-of-ice-age-year-60000-ad.html?m=1
The excess CO2 above the temperature-dictated equilibrium (now 280 ppm) is decreasing exponentially with time with the halving time currently shorter than a century (it may be a bit longer when life is mostly frozen and slowly reacts to the changes). It’s easy to see why it’s so. We’re emitting the equivalent of 4 ppm of CO2 in the atmosphere every year but the concentration only grows by 2 ppm. So the remaining 2 ppm are absorbed. They are absorbed *because* the CO2 is elevated so the consuming processes are strengthened. They would be strengthened even if we didn’t emit any CO2 because these ocean and life processes don’t care about the emissions in the last year – they only care about the immediate CO2 concentration in their vicinity. So the concentration would begin to drop by 2 ppm a year if we stopped making any emissions tomorrow.
From any realistic concentration – 2,000 ppm, if you wish – we would be back below 300 ppm within at most a few centuries.
To make a prediction it is necessary to know the planet’s sensitivity to a doubling of CO2 (Very low unfortunately, it appears a doubling of atmospheric CO2 will warm the planet less than 1C) and to understand what causes the glacial/interglacial cycle. If I understand the mechanisms that control the glacial/interglacial cycle, the increase in atmospheric CO2 will not inhibit the start of the next interglacial. The current orbital position is optimum for terminating this interglacial period, if the below mechanism is what terminates interglacial periods. The current observations appear to support the assertion that we are going to experience what causes either a Heinrich event or a Dansgaard-Oeschger cycle. I will if and when there is the start of unambiguous global cooling make a formal presentation to explain the mechanisms and what to expect next.
An analysis of geomagnetic dipole lows and related geomagnetic excursion over the last 800k years from (the Sint-800) deep sea floor analysis data base shows that 12 of the interglacial terminations correlate with geomagnetic excursions. It is asserted that geomagnetic excursion is what terminates the interglacial not insolation at N65 in July and August. If that assertion is correct, the next question is what causes the cyclic geomagnetic excursions?
http://openearthsystems.org/data/readings/Open%20Earth%20Library-%20Topical%20Folders/Core%20Dynamics/Thouveny%20et%20al%202008.pdf
See table 2 in this paper.
Paleoclimatic context of geomagnetic dipole lows and excursions in the Brunhes, clue for an orbital influence on the geodynamo?
An observation to support the above assertion (that insolation at 65N in July and August does not control the glacial/interglacial cycle) is the Younger Dryas abrupt cooling event that occurred 12,900 years ago. 12,900 years ago, insolation at N65 in July and August was close to the peak for the Holocene interglacial period. Then some external forcing function created a geomagnetic excursion which in turn caused the planet to return to glacial cold for a period of 1000 years with 70% of the cooling occurring in less than a decade. The logic point is the geomagnetic excursion is the 800 pound gorilla, the massive forcing function which can make it cold in both summer and winter which causes the ice sheets to form and grow or vice verse as the massive forcing function can ultimately strengthen geomagnetic field which causes the planet to be warmer in both winter and summer. The external forcing function terminates and initiates the interglacial periods by inhibiting or strengthening the geomagnetic field.
The authors of the above paper speculated that orbital changes somehow caused the geomagnetic lows. That speculation is not correct. The mechanism, the forcing function that causes cyclic abrupt changes to the geomagnetic field is a restart of the solar magnetic cycle after it has been interrupted. There are burn marks on the surface of the planet that correlate with Younger Dryas abrupt cooling period (the duration of the Younger Dryas cooling event is roughly 1000 years). There are burn marks on the planet’s surface that correlate with other geomagnetic excursions.
What controls whether the massive discharge from the sun ultimately attempts to reverse or strengths the geomagnetic field is the orbital position when the event occurs. Greater orbital eccentricity and orbital tilt amplifies the mechanism in how much the strikes affects the geomagnetic field strength. Whether the Northern Hemisphere or the Southern Hemisphere is in summer or winter (point towards or away from the sun at perihelion – closest point to the sun) determines whether the strikes ultimately strengthen or attempt to reverse the geomagnetic field. In all cases the strike temporary reduces the intensity of the geomagnetic field as the field in the core resists a field change. Then over time equilibrium is reached as current flows through the earth attempting balance charge on the surface with the core.
In the last 10 years geomagnetic specialists have discovered and reached consensus that the geomagnetic field has in the past abruptly changed (the speed of the change and the number of the changes is orders of magnitude higher than previous assumptions based on the theoretical origin of the geomagnetic field and the theoretical origin of geomagnetic field changes) and that the changes correlate with climate changes.
There are two types of observed rapid geomagnetic field changes: 1) archeomagnetic jerks at which time the geomagnetic field axis abruptly changes by 10 to 15 degrees and 2) geomagnetic excursions which is a failed or very short lived reversal at which time the intensity of the geomagnetic field drops by a factor of 5 to 10. The geomagnetic field specialists have multiple hypotheses to try to explain why the geomagnetic field is abruptly changing.
An observation that supports the assertion that solar changes modulate the geomagnetic field and that we are going to experience either a D-O cycle or a Heinrich event is the sudden unexplained increase in the North geomagnetic pole drift velocity by a factor of 4 to 5 starting in 1990’s which correlates with the inhibiting of Svensmark’s GCR mechanism.
http://onlinelibrary.wiley.com/doi/10.1029/2010EO510001/pdf
What Caused Recent Acceleration of the North Magnetic Pole Drift?
The north magnetic pole (NMP) is the point at the Earth’s surface where the geomagnetic field is directed vertically downward. It drifts in time as a result of core convection, which sustains the Earth’s main magnetic field through the geodynamo process. During the 1990s the NMP drift speed suddenly increased from 15 kilometers per year at the start of the decade to 55 kilometers per year by the decade’s end. This acceleration was all the more surprising given that the NMP drift speed had remained less than 15 kilometers per year over the previous 150 years of observation. … ….Why did NMP drift accelerate in the 1990s? Answering this question may require revising a long-held assumption about processes in the core at the origin of fluctuations in the intensity and direction of the Earth’s magnetic field on decadal to secular time scales, and hints at the existence of a hidden plume rising within the core under the Arctic… ….Sudden Acceleration in the 1990s Observations from satellites, magnetic observatories, and field surveys show that the NMP drift speed suddenly increased in the 1990s [Newitt and Barton, 1996; Newitt et al., 2002], from 15 kilometers per year in 1990 to about 60 kilometers per year in 2002, after which it slowly decreased [Olsen and Mandea, 2007; Newitt et al., 2009]. This phenomenon was observed in both field survey measurements and global geomagnetic models (Figure 1a). It followed more than 150 years of slow drift at less than 15 kilometers per year, starting with the first location of the NMP by Ross. This sudden acceleration contrasts with the behavior of the south magnetic pole, which has a drift speed that has never exceeded 15 kilometers per year since the beginning of the twentieth century [Olsen and Mandea, 2007]
http://eprints.whiterose.ac.uk/416/
Is the geodynamo process intrinsically unstable?
Recent palaeomagnetic studies suggest that excursions of the geomagnetic field, during which the intensity drops suddenly by a factor of 5 to 10 and the local direction changes dramatically, are more common than previously expected. The `normal’ state of the geomagnetic field, dominated by an axial dipole, seems to be interrupted every 30 to 100 kyr; it may not therefore be as stable as we thought.
http://geosci.uchicago.edu/~rtp1/BardPapers/responseCourtillotEPSL07.pdf
Response to Comment on “Are there connections between Earth’s magnetic field and climate?, Earth Planet. Sci. Lett., 253, 328–339, 2007” by Bard, E., and Delaygue, M., Earth Planet. Sci. Lett., in press, 2007
Also, we wish to recall that evidence of a correlation between archeomagnetic jerks and cooling events (in a region extending from the eastern North Atlantic to the Middle East) now covers a period of 5 millenia and involves 10 events (see f.i. Figure 1 of Gallet and Genevey, 2007). The climatic record uses a combination of results from Bond et al (2001), history of Swiss glaciers (Holzhauser et al, 2005) and historical accounts reviewed by Le Roy Ladurie (2004). Recent high-resolution paleomagnetic records (e.g. Snowball and Sandgren, 2004; St-Onge et al., 2003) and global geomagnetic field modeling (Korte and Constable, 2006) support the idea that part of the centennial-scale fluctuations in 14C production may have been influenced by previously unmodeled rapid dipole field variations. In any case, the relationship between climate, the Sun and the geomagnetic field could be more complex than previously imagined. And the previous points allow the possibility for some connection between the geomagnetic field and climate over these time scales.
FOR THOSE INTERESTED — W.F. Ruddiman is one of the ‘godfathers’ of the idea that humans have lengthened the present interglacial. He summarized, after publishing various aspects of the idea for almost 10 yrs, in his book, ‘Plows, Plagues and Petroleum – how humans took control of climate’, 2005 (Princeton University Press). The book was published about the same time as the above paper.
‘Jimbo says: (April 27, 2013 at 7:35 am)
I vaguely recall that during the late Ordovician Co2 was over 4,000 parts per million. (Today 400ppm).
I vaguely recall during the late Ordovician there was an ice age.
I vaguely recall that Co2 remained at over 3,000 ppm throughout the glaciation.’
Yes, yes, but that was NON-anthropogenic CO2!