Guest post by Dr. David Archibald
The Earth is currently in an interglacial period of an ice age that started about two and a half million years ago. The Earth’s current ice age is primarily caused by Antarctica drifting over the South Pole 30 million years ago. This meant that a large area of the Earth’s surface changed from being very low-albedo ocean to highly reflective ice and snow. The first small glaciers were formed in Antarctica perhaps as long ago as 40 million years. They expanded gradually until, about 20 million years ago, a permanent ice sheet covered the whole Antarctic continent. About 10 million years later, glaciers appeared on the high mountains of Alaska, and about 3 million years ago, ice sheets developed on lower ground in high northerly latitudes.
Pacific Ocean bottom water temperatures started declining 40 million years ago, falling 10° C to the current 3° C. The band of high ocean temperatures (above 25° C) also contracted towards the equator, from 45° latitude to 20°. Eventually the oceans lost enough heat that the Earth’s orbital parameters started causing surges in ice formation. There are three orbital parameters: eccentricity, precession and obliquity, shown in Figure 1.
Figure 1: Orbital Parameters: Eccentricity, Precession and Obliquity- click for larger image
This figure is developed from A.L.Berger, 1978, Long Term Variations of Daily Insolation and Quaternary Climatic Changes, Journal of the Atmospheric Sciences, volume 35 (12), 2362-2367.
Eccentricity is caused by changes in the shape of the Earth’s orbit due to the gravitational attraction of other planets. Precession is the change of direction of rotation. Obliquity is the tilt of the axis. When these effects aligned, their effect is reinforced. From three million years ago to about 800,000 years ago, the dominant pattern of glaciation corresponded to the 41,000 year period of changes in the Earth’s obliquity. Since then, a 100,000 year cycle has been dominant.
Ice ages occur because the summer sun in the northern hemisphere does not get hot enough to melt all the ice that accumulates over winter. Ice has a much higher reflectivity than rocks or vegetation, and so reflects more sunlight into space and the cooling is reinforced. Eventually the orbital parameters change back and warming occurs. Glacial periods tend to cool slowly and warm abruptly. Because the Earth’s orbital parameters can be calculated, the amount of sunlight in high northern latitudes can be calculated.
Figure 2: June Mid-Month Insolation at 65° North – click for larger image
This figure is derived from M.F.Loutre and A.Berger, 2000, Future Climate Changes: Are we entering an exceptionally long interglacial?, Climatic Change 46, 61-90
Figure 2 shows how that translates to insolation (sunshine) at 65° North. The recent peak in insolation was 11,000 years ago at the end of the last glacial period. It has since declined by about 10% to 476 watts per square metre. Insolation will rise from here for the next 30,000 years, but it will still be low enough for the next glaciation to form. This is shown by Figure 3 of Northern Hemisphere ice volume for the last 200,000 years and a projection for the next 130,000 years. According to these calculations, the Earth is at the beginning of a 20,000 year plunge into the next ice age.
The reason why the Earth doesn’t respond more rapidly to changes in insolation is due to the retained heat in the oceans, which smoothes the whole process over thousands of years. Over the short term, the oceans are very responsive to changes in solar activity. Figure 5 shows the very strong correlation between the annual rate of sea level rise and solar cycles over the 20th century. The sea level rise of the 20th century can largely be attributed to a more active Sun relative to the 19th century. About 70% of the sea level rise of the 20th century was due to thermal expansion of the oceans, with the rest due to melting glaciers.
Figure 3: Future Glaciation – click for larger image
This figure is derived from M.F.Loutre and A.Berger, 2000, Future Climate Changes: Are we entering an exceptionally long interglacial?, Climatic Change 46, 61-90
Figure 4: The Correlation between Sea Level Rise and Solar Cycles over the 20th Century. – click for larger image
The sea level data is derived from S.Holgate, Decadal rates of sea level change during the twentieth century, Proudman Oceanic Laboratory, Liverpool, UK.
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Why did temperatures start declining 40 million years ago? Is the sun cooling down?
The article indicates that Antartica started to cover the south pole at that time.
No. I believe the sun’s irradiance is slowly increasing over geologic time scales.
The temperature decline may be related to the earth entering one of the spiral arms of the Galaxy from a relatively less active region for GCR, but I don’t think anyone knows for sure.
I was wondering, since the time stamp is about the same, would we get enough energy when the supermassive black hole in the center of the milky way turns on to get us back to the temperatures that existed through most of the geological record with higher life forms?
How much of the night sky be lit up with the two jets blasting out perpendicular from the center of the milky way from our vantage point in the galaxy?
Maybe an event like this effects the output of the sun itself ….
Being in and out of spiral arms may be a possibility.
Below someone reminds me of the time with water over the poles and Pangea the supercontinent girdling the globe. Perfect configuration to avoid Milankovitch cycles. Fortunately we still have one pole with water to avoid that other scenario … Snowball Earth. Although the theory that ever happened is not supported by a large amount of evidence from what I’ve seen.
Antarctica started drifting over the south pole as it separated from South America. As glaciers and an ice cap formed, sea levels dropped, and circumpolar winds started insulating antarctica from the rest of the planet. Then as the continent totally separated from SA, a circumpolar ocean current started up, that further isolated and insulated Antarctica from the rest of the global climate. This all made Antarctica a sort of refrigeration compressor.
Since about 22 million y.a., the Antarctice ice caps have been stable during some periods of significantly greater warmth and higher CO2 levels than at present. Expeditions to the buried glaciers in the katabatic canyons have verified this, which has demolished the disasturbationist theory claims of imminent doom.
Is “disasturbation” a new word?
Apt.
“The Earth’s current ice age is primarily caused by Antarctica drifting over the South Pole 30 million years ago. This meant that a large area of the Earth’s surface changed from being very low-albedo ocean to highly reflective ice and snow. “
Antarctica has been slowly drifting SE in a continental drift sense during the Tertiary. Starting 40 mya, the first edges of the continent were reaching latitudes greater than 85 South. During the last 40 million years, the drift has continued so that 90 S is located in the middle of the continent. If the spreading continues about 40 million years in the future, it will be mainly north of 85 degrees south.
The importance is that as the land mass moved further south, ice could begin to accumulate on it and that started a cooling feed back loop.
Interesting post.
A couple of minor points:
1. It is difficult to conceive of Pacific bottom waters’ ever having been 13 degrees Celsius. Are there other corroborations of this number?
2. Figure 3 appears to be inverted.
Harold, read the scale again. The graph is correct…more ice is towards the bottom of the graph! 🙂
OK, I get it. Thank you! Intuitive graphs, though, remain my favorite kind. This one does not pass the test (for me).
I understand that the scale increases toward the bottom, however I think the author made a mistake in formatting the graph that way. Many people will fail to notice that and misunderstand. They will think “He predicts the ice is melting!”
Thanks, I missed that 1st time through… I’d suggest changing the caption to “Future (inverse) Glaciation”.
Being from down under David Archibald will be standing upside down. 🙂
Figure 3 indicates a potential emergency crisis.
Buy bricks now! You can put them on your SUV’s fast pedal in the near future to protect the Earth from Climate Change.
1. It is difficult to conceive of Pacific bottom waters’ ever having been 13 degrees Celsius.
I agree. I was taught in elementary school that bottom waters always stay at 4 degrees (probably slightly different for salt water), since the density at this temperature is the highest. To reach 13 degrees I guess extreme currents would be necessary, so this figure sounds like nonsense.
[snip – take questions about schooling elsewhere please]
Because the temperature of rocks increase with depth, it would also make sense for the deep ocean to be warm. But convection can remove that heat. The ocean bottom is kept cold by water from the poles. So all that’s needed to warm the ocean bottom is for the poles to warm, and we’re being told that it’s easy for the Arctic Ocean to warm. The south polar area is oddly isolated by the current flowing all the way around it, so to keep the Pacific bottom warm there would be competition between cold water from the Antarctic and the warming caused by upwellings such as off the coast of Peru.
Same question, 10C at the bottom?. Plain physics tells you that water under serious pressurte will tend to the temperature for which it has its smallest volume, which for water is about 4 degrees C. No matter how warm or cold the surface, the bottom of the oceans is always 4C everywhere, except near thermal vents, of course. Yet you mention 10C and I have seen similar numbers in connection with carbonate sediments. So, how come, and do you have references? Apart from that, good post, although I must mention that I was told about the Milankovitch cycles already at secundary school in the 1960-ies by an enthousiastic teacher.
Hello Ed,
the heaviest water sinks to the bottom, regardless of its temperature. There may not even be any 4 C water if the overall average temperature is high enough. When you start heating your tea water there may be some 4 C just having come right out from the tap, but very soon the coldest water is close to 100 C.
“Precession is the change of direction of rotation”
It makes it sound like the sun rises in the west during the ice age. Maybe say the “Change in the direction of the AXIS of rotation” to be a bit more accurate.
Also, the bottom waters of the pacific ocean at 13 C? Where does that information come from? It is pretty tough for me to swallow.
Precession can be described as the wobble of the earth as it spins on its axis similar to the wobble of a top as it slowa down. A good description of Milankovitch cycles can be found here.
http://www.homepage.montana.edu/~geol445/hyperglac/time1/milankov.htm
moderator, please snip previous. The link helped me understand the difference. tnx for the trouble.
Um, I thought the wobble was ‘nutation’ while precession was the ‘rotation of the axis of rotation’.
http://en.wikipedia.org/wiki/Nutation
Precession is the effect when a force is applied to a gyro axis, where the actual movement is displaced by 90º. Wobble is Nutation as noted by E. M. Smith & others.
Precession can be demonstrated with a toy gyro, Push the top, translate that force to the rotational disc & rotate 90º in the direction of rotation. That is the direction the gyro will tilt.
DaveE.
E.M.Smith (13:18:49)
Thanks for the correction. Cheers
I thought of that, too. It would be clearer.
Help!
I thought precession was the advancing of the equinoxes at the ecliptic, which is caused by the proturbent matter about the equator. Are we talking about the same thing?
Please explain “change in the direction of the AXIS of rotation”
markm
The link provided by E. M Smith shows precession nicely. The rotational axis (which is a vector) is itself rotating around another axis. So, the axis of rotation is constantly changing direction. The precession causes an apparent motion of the position of the sun at equinox against the stellar background.
http://en.wikipedia.org/wiki/Nutation
http://en.wikipedia.org/wiki/Precession_(astronomy)
Nice post David.
Here is nice animatable graphic showing Antarctica continental drift over time.
Between 50 million to 40 million years ago, the Australian plate separated from Antarctica and then Antarctica moved far enough away from the South American plate (while simultaneously drifting toward and over the South Pole) so that the southern ocean current could isolate it from warmer ocean patterns. ie. Glaciation.
And CO2 is not involved in continental drift (although I’m sure some model could simulate it).
http://www.exploratorium.edu/origins/antarctica/ideas/gondwana2.html
Bill,
Nice animation. Do you have one for the northern hemisphere as well??
Thanks, Tom
navigate around these pages – a good resource:
http://www.scotese.com/
Mike
A little off topic but this change in the location of Antarctica reminds me of how long the penguins have occupied Antarctica and how long the Emperor penguins have been making the migration to breed!! Now that’s what I call adaptation!!
Please: “And CO2 is not involved in continental drift”. CD was Alfred Wegener’s theory, for which he was hooted out of polite scientific society. He actually had the correct idea, and the mechanism now known as “plate tectonics” explains how, for example, one can cut out maps of Africa and South America, put them together, and they fit very well. Today, he’s (posthumously) back in good standing.
Geology is replete with many such great controversies. The latest of course is “global warming” var. “anthropogenic”. One camp is again trying to hoot another out of the fold. We should know better by now.
We should know better by now that man is insignificant when it comes to Solar scales.
Epicycles met Ockham’s razor.
So too will CO2 forcing. When going to great lengths to smash a square peg into a round hole, the first clue is the splinters and destroyed carpentry.
A reliable take, we’re obliged.
It would be interesting to see how these figures relate with Sun movements around barycenter.
it would have been helpful for the article to have referred to the third of the Milankovitch cycles – the variations in the elliptical orbit of the Earth. The three together (obliquity, changes in the precession), act like biorythms when they can reinforce or cancel each other in varying degrees.
In any event, as a Geographer, my understanding that we are in the Fourth Great Ice Age of the earth’s history. It actually started nearly forty million years ago, became somewhat more intense about 16 million years and ago then worsened a lot 3 million years ago. The article is right in that there are alternating glacial / interglacial periods.
For the record, the first was a possible snowball earth approx 2,500 million years ago, the second a probable snowball earth about 750 million years ago and the third (the Kerroo if memory serves) was about 380 million years ago (I stand to be corrected on the actual figures)
As a counterpoint, we should be aware that the Cretaceous (160m years ago) was the total opposite – so hot that there was no ice anywhere on the planet. Since then it has been downhill all the way !
Seems DA is marching thru his info with the Cana protocol, it just seems to get better at each turn. The simplicity of presentation here of something that has always humbled me in text is arresting.
Thanks to Anthony for posting this. I did write this as a simple summary. Lautre and Berger are loony warmers, but they left enough information in their papers to see what was going on. I turned their graphs around so that time marched to the right, as it should. The Holgate – solar cycle graphic came from a graphic that was originally posted on Climate Audit a couple of years ago. That relationship is worth a paper. Lautre and Berger dreamt up a 50,000 year Holocene and said we would have another glacial period after that. They weren’t going to be so completely loony as to say that we would never have another glacial.
What is going to happen is that Mankind is going to burn through the rocks we can economically burn over the next couple of hundred years and the oceans are going to swallow 97% of that. The net result will be an increase in the biological productivity of the oceans. There will be no other discernible result.
On the current minimum, in the absence of larger sunspot numbers to calculate it from, the month of solar minimum is likely to be put in the middle of the period of flatlined F 10.7 radio flux. On that basis, if activity ramped up tomorrow, the month of minimum would be November 2008. Otherwise, each extra two months of flatline adds another month. Each extra month of minimum takes 0.06 degrees C off the temperature of the mid-latitudes over Solar Cycle 24.
For those of us amongst us in solar denial, I recommend Hoyt and Schatten’s “The Role of the Sun in Climate Change”. They note that the first person to discern a link between solar cycles and climate was in ancient Greece in 400 BC. That person was only equipped with an open mind.
The TSI bird is in it’s first solar cycle so what minimum looks like no-one knows.
Just threw this together for a quick look. (taken from 6 hour data, lot of data points)
Is it correct? Can’t be sure.
http://www.gpsl.net/climate/data/TSI_2009-02-24a.png
David, you say: “Lautre and Berger dreamt up a 50,000 year Holocene and said we would have another glacial period after that.” That is consistent with what I see in their paper, but your figure 3 above (which you say is from their paper) shows glaciation starting now, not in 50,000 years.
Am I missing something here, or is there an error somewhere?
“Why did temperatures start declining 40 million years ago? Is the sun cooling down?”
The major portion of the cause lies with terrestrial continent formations. Beginning in the 60’s plate tectonics observed, as DA alludes, to Pangea formations with most all of the land in one continent lead to peak global temps.
The reverse, ice ages recur with land ‘evenly’ distributed about the globe. While some have noted here that the NH and SH appear decoupled, the situation is worse with a Pangea configuration and one ocean of size.
Gary,
If you take a globe of the world and take it out of it’s mount, turn the globe so as Antarctica is on the Equator all you can see is one big ocean, makes you wonder what is up and what is down, I myself think that the Northern Hemisphere with all the extra weight must be down, but as I have not traveled in space and found out what is up and what is down I remain ignorant.
Well, the Northern Hemisphere is probably not all that much heavier. This is because continental crust is lighter than oceanic crust (density-wise). This is why, for the most part, oceanic crust subducts under continental crust.
Thanks, I forgot about that.
It think I ran into that discussion when looking at the ‘Snowball Earth’ theory. Pangea with water over the poles made us warmer and kept us out of the Milankovitch cycle …
It would be nice if the Milky Way remains an abstraction and not an influence.
Here is a site with a working model, which you can move around, of the cycles in question. Its really good.
http://apollo.lsc.vsc.edu/classes/met130/notes/chapter16/graphics/71_Orbital_Fluctuations/A_71.swf
Great animation Edward. Thanks
My pleasure.
David,
Is it not true that although insolation will begin to increase in the near future (geological time) the current level of insolation will continue to decrease slightly before then?
The graphic says that insolation at 65 north will be higher than present for the next 50,000 years. Not enough to stop a glaciation though.
Very nice and clear explanation of the orbital parameters. Some tectonic events also should be noted: 1) the separation of the Indian subcontinent from Antarctica and subsequent contact with Asia caused the uplift of the Himalayan plateau and changed circulation patterns between 40 and 10 million years ago (mya), 2) opening of the Drake passage between South America and Antarctica allowed a circumpolar current that limited the flow of warm water as far south as before, 3) uplift of the isthmus between North and South America caused more warm waters to flow poleward about 6 mya. The physical factors are given little acknowledgment in the media, yet are by far the greater contributors to the basic climate we have.
yes the start of the ice ages 2.5 mya corresponds to the formation of the gulf stream/THC. strangely nobody seem to realise that this should act like a car radiator and cool the earth by transporting heat and moisture from the tropics to the high latitudes where heat can escape easier and moisture forms more clouds increasing albedo. Of course people in the north atlantic think the gulfstream warms the entire world because it warms their own. However the system is a little bigger than the north atlantic
cheers
Excellent point.
Absolutely….. and one would have to admit, these tectonic processes are much more substantial than a molecule of CO2 gas….. and more believable in cause and effect.
Is it so difficult to believe that carbon dioxide is a greenhouse gas? Is it so difficult to understand that man has pumped billions of tons of CO2 into the atmosphere? Is it so difficult to believe that the amount of carbon dioxide in the atmosphere is steadily increasing and is it so difficult to believe that all this will have some effect on climate?
Of course there are many other factors which affect our climate, from the sun to the inside of the earth but to blindly ignore any one of them is poor science.
Don’t forget the regulation and stabilizing effect of water and water vapor, which has kept the climate stable for about a billion years. I was taught this 35 years ago in high school. It is bizarre to me how this has been corrupted by modelers.
Dennis Ward,
[snip]
No one is blindly ignoring demon CO2. With Pangea formations comes interruption of the oceanic circulation of polar waters between hemispheres, the global average temperature has recurrently rising to 72 degrees F.
CO2 follows temperature rising to roughly 10 times its crustal abundance as its solubility in the oceans decreases. Episodes of extreme volcanism, possibly induced by the odd asteroid hit serve to accelerate the process.
Your piddling Gtons aren’t much against the background of natural fluctuations.
Concerning fig.3 attributed to Loutre and Berger, there is a Science paper of the two authors from 2002, vol 297, p. 1287, which gives an almost constant (and close to zero) northern ice sheet volume over the next 50 ka, fitting to their title: ‘an exceptionally long interglacial ahead?’. Only a drop of CO2 concentration to 210 ppm would induce earlier glaciation, significant after 20 ka.
However, my main concern is fig. 4, which does not really agree with the data from University of Colorado:http://sealevel.colorado.edu/current/sl_noib_global.jpg
There are no hints given, how terrestric data, taken since 1900, can be of higher quality than the recent satellite data, which do not seem to indicate any signature of SC 23.
“Only a drop of CO2 concentration to 210 ppm would induce earlier glaciation”
I believe your maths are open to question. First one needs to demonstrate that CO2 has ever changed the Earth’s temperature rather than being, in fact, the other way around.
Anyone who wants to learn more about how Milankovitch was validated can read Imbries’ book. Its excellent.
The position of the continents determines how excess heat or cold is distributed and how efficiently it is transported.
The reason why the Earth doesn’t respond more rapidly to changes in insolation is due to the retained heat in the oceans, which smoothes the whole process over thousands of years. Over the short term, the oceans are very responsive to changes in solar activity.
You can’t have both.
Figure 5 shows the very strong correlation between the annual rate of sea level rise and solar cycles over the 20th century.
The sea level even knew that cycle 19 was coming and started rising way before.
The sea level rise of the 20th century can largely be attributed to a more active Sun relative to the 19th century.
Except that the Sun was not more active during the 20th century.
You can’t have both.
There’s a much better correlation between solar cycles and ocean levels, than there is between CO2 and temperature.
they are both lousy
Leif,
In regards to solar activity during the 20th century that these graphs are wrong?
http://penoflight.com/climatebuzz/Files/Solar1415ext4.jpg
http://penoflight.com/climatebuzz/Files/sunspot_num_graph_big.jpg
well, the first one does not extend into the 19th century and therefore does address the issue of comparing 19th and 20th.
The second one is indeed wrong. It should look more like the Figure on page 7 of http://www.leif.org/research/Napa%20Solar%20Cycle%2024.pdf
Lief,
It’s a fine paper, but it put a crick in my neck.
Lol, I noticed that too. Such smart oceans we have! That or they’re so powerful they influence the sun! /sarcasm
Leif,
Your Figure 7 goes back to 1750. Lee’s graph goes back to circa 1610. The portion of Lee’s graph from 1750 on is virtually identical to your Figure 7. Why is your graph correct and his wrong?
Remember that the PDO switched to a cool phase in 1945, so several changes in the ocean behavior are to be expected around that time.
“Except that the Sun was not more active during the 20th century.”
Actually, it was. The solar cycles of the 20th have had far higher peak sunspot counts and higher 11 year running average sunspot counts than previous centuries. We are now entering an era more akin to the Dalton Minimum of the early 19th century.
They certainly spent a lot more time on the high side heating up the place than they did on the low side, which was short & elevated.
Low cycles spend a lot of time at the bottom, freezing the heck out of things and barely manage to get themselves high enough to simply halt any more freezing.
David,
Your figure 3 seems to have time reversed from Berger et al (2002). That would explain the discrepency noted by Werner above.
Now that I look closer, my reversed time comment is not correct, but your figure is definitely different for future projection than Berger et al (2002).
Spectrum of 100-kyr glacial cycle: Orbital inclination, not eccentricity
http://www.pnas.org/content/94/16/8329.full
” The hypothesis that variations in inclination are responsible for the 100-kyr fluctuations cleanly solves three of the difficulties associated with the hypothesis that variations in eccentricity are responsible. First, the inclination shows a single narrow peak, in agreement with the spectrum of climate proxy records. Second, the variation in inclination does not show any peak at 400 kyr, again in agreement with observations. Third, the inclination hypothesis satisfactorily deals with the causality issue. “
SO it’s true what the doomsayers say: The Earth IS spinning out of control 🙂
That’s got to be due to all the SUVs concentrated in one hemisphere. Someone needs to move the tire weights around the rims. 😉
The time scales mentioned are academic. CO2 is being taxed now.
We are told there is only four years to save the planet.
We have screwed the planet over 150 years and we will fix it in three!!!
Okay. I can wait three years to see what happens.
Where can I lay a bet on the outcome?
Not in Vegas. They only take bets they are sure to win.
Werner Weber (08:46:02)
I have to say, I agree with you. In a paper published shortly before the data from which the curve in Figure 4 above was produced, Holgate published a paper on the rate of sea level rise since the mid-19th century in which a dominant effector was the stratospheric aerosolic depth (e.g from the effects of volcanic eruptions). See Figure 6 of
S. Jevrejeva, A. Grinsted, J. C. Moore, S. Holgate (2006) Nonlinear trends and multiyear cycles in sea level records. J. Geophys. Res. 111, C09012.
…and there is no indication of a solar cycle contribution in that analysis.
In the Holgate’s paper from which the data in Figure 4 in the top post was drawn, Holgate selected a very small sub-group of 9 coastal tide guages (in N. America and Europe and 1 in Hawaii), and perhaps it is this subset of stations in shallow coastal waters that respond somewhat more quickly than the oceans as a whole to solar irradiation changes through the solar cycle, that give rise to a variation that seems to track (somewhat) the solar cycle. Of course that would require that the local sea levels in the subset were “out of equilibrium” with the oceans as a whole in terms of sea level….
Likely he selected coastal tide guages located in areas that did not experience significant subsidence or uplift/rebound that would possibly skew results, particularly given that tectonic processes are very erratic in their changes consistent with major earthquakes.
“and there is no indication of a solar cycle contribution in that analysis.”
Because it wasn’t considered?
Richard111,
You can bet here: click
Your bet is tax deductible, too.
[snip – enough about gambling and IRS]
Lord Nicholas Stern is at it again, predicting climate change will result in “extended world war.”
http://www.foxnews.com/story/0,2933,498133,00.html
“Stern, author of a major British government report detailing the cost of climate change, was one of a select group of two dozen — environment ministers, climate negotiators and experts from 16 nations — scheduled to fly to Antarctica to learn firsthand how global warming might melt its ice into the sea, raising ocean levels worldwide. . . .”
“. . . If the world’s nations act responsibly, Stern said, they will achieve “zero-carbon” electricity production and zero-carbon road transport by 2050 — by replacing coal power plants with wind, solar or other energy sources that emit no carbon dioxide, and fossil fuel-burning vehicles with cars running on electric or other “clean” energy. Then warming could be contained to a 2-degree-Celsius (3.4-degree-Fahrenheit) rise this century, he said.”
Yes, I think a 2 degree Celsius per century is an achievable goal. In fact, I’d bet we could even keep it down to 1.2 degrees.
If he keeps saying it loudly enough it will become a self-fulfilling prophecy.
http://news.yahoo.com/nphotos/Snow-storms-hit-US/ss/events/sc/121908winterweather
Mike McMillan (10:36:56) :
Lord Nicholas Stern is at it again, predicting climate change will result in “extended world war.”
http://www.foxnews.com/story/0,2933,498133,00.html
From the link above:
“After he spoke, Norwegian organizers announced that the forecast looked good for Stern and the rest to fly south on Sunday to further ponder the future while meeting with scientists in the forbidding vastness of Antarctica.”
Picture of Norwegian minister of the environment Erik Solheim in Antarctica
http://www.aftenposten.no/nyheter/uriks/article2942300.ece
“He leads an expedition consisting of environment ministers from China, the Czech Republic, Finland, Russia, Sweden, Great Britain, Algeria, as well as representatives of seven other countries, to visit Antarctica”
The much more likely trigger of world war would be a global famine caused by drought induced crop failures after a shift to a cooler regime with lower CO2 levels.
WWII was partly about “living room” and the desire to control the Ukraine bread basket… The French Revolution was partly about the lack of wheat during a Little Ice Age crop failure. Hungry people start shooting.
Crops grow well when it is warm, wet, and CO2 rich. They fail when it is cold, dry, and CO2 poor. Cold and Dry come together as a set. We are presently getting dryer and the PDO et. al. and Landscheidt hypothesis are pointing to colder. Now we are going to push for much less CO2. He may have his outcome right, but his drivers are backwards…
You are correct. Warmer = more crops + less wars. Cooler = less crops + more wars.
http://www.scidev.net/en/news/climate-change-sparked-historical-wars-in-china.html
Although, note the AGW supporting speculation that isn’t supported by the study.
Re getting drier, this from NOAA re California drought should be interesting. Note that Shasta hydroelectric generation is cut back to half of normal. The farms are affected, too.
click
I guess we will know in about 4 weeks how much these recent rains/snowfalls helped.
What, as distinct from an ‘unextended’ World War? Not only does he mouth a great deal of drivel, he expresses it poorly.
“extended world war.”?
Modern force on force conflicts are likely to be short rather than extended as smart weapons and cruise missiles take out the major points of interest on both sides. Hence extremely expensive (another limiting factor) in terms of blood and treasure…
’nuff said – topic for another blog.
I am inspired by Edward Morgan’s post to believe that the Antarctic Circumpolar Current in its modern path started forming about 40 million years ago. The current had earlier been forced by the near connection of Australia and Antarctica to travel far to the North along the Northern coast of Australia before dropping south to the pole again. This would have brought relatively warm water down to the South Pole and kept Antarctica uncovered by permanent ice. Perhaps the poleward plunge of Antarctica and a change in current path together account for the change in frequency of the ice ages. Gary, has this idea been looked into and discarded?
It also looks to me that strong currents like these over millions of years can even help nudge continents along their paths. Relatively small forces summed over long periods can have important consequences. This is uninformed speculation on my part.
Ocean currents have little, if anything, to do with moving continents along on their journey around the earth. Mantle convection is what is thought to be the cause of continental drift.
STOP CONTINENTAL DRIFT!!
REUNITE GONDWANALAND!!
STOP CONTINENTAL DRIFT!!
REUNITE GONDWANALAND AND LAURASIA!!!
I want the T-shirt…
That link again for anyone who missed it. You can play with the model in question in this topic
http://apollo.lsc.vsc.edu/classes/met130/notes/chapter16/graphics/71_Orbital_Fluctuations/A_71.swf
Glad you liked it John (not convinced you meant me though)
Ocean currents do not contribute to the motion of the plates. There is just no way to move that much material. Plates are more than just the crust; it’s the crust and upper rigid part of the mantle which forms a plate. These plates are many a kilometer thick and have an incredible amount of mass.
Density is the driver of plate tectonics.
Incidentally, since the title of this post mentions sea level, the rate of plate motion (more specifically the rate of production of new ocean floor) has the greatest control on large scale changes in global sea-level.
Q: “Where can I lay a bet on the outcome?”
A: hubdub.com . But, alas, it’s only play money.
Um, need I point out that the stock market and futures markets offer all the real money betting options you could ever want?
Bet on drought via grain futures or “MOO” “COW” “WOOD” “JJG” or “DBA” tickers (ag inputs, animals, trees, grain, and general ag basket; respectively). Bet on bad winter with road salt makers (ticker escapes me at the moment, though I own it… ). Bet on war with ‘aerospace & defense’ or bet on cold via heating oil (UHN) or natural gas (UNG) both up today, btw.
Disclosure: I own JJG and some “MOO” along with some natural gas producers and oil. I don’t think my saying anything about them here is going to move the world grain or oil price, though 8-}
On a related note, today’s Dot Earth blog in the NY Times says that Al Gore has pulled a graph from his presentation which purported to blame accelerating numbers of disasters on global warming. Perhaps someday Science will pull ahead of Advocacy in the climate horse race, even in the legacy media, and articles such as this WUWT one will help.
http://dotearth.blogs.nytimes.com/2009/02/23/gore-pulls-slide-of-disaster-trends/?ref=science
I worked at an outstation in the Andes during the 1980-s and we relied for the forecast on an “interpolation” between Santiago and Antofagasta. One day we found on the telex: today no weather (forecast) because of the weather. It was that bad. So
if Al Gores disasters come fast and strong, then we will have to do without weather forecasts altogether, so that we can all stop worrying about it.
Strike frequency and replace with severity in my post above.
“About 70% of the sea level rise of the 20th century was due to thermal expansion of the oceans, with the rest due to melting glaciers.”
Several times I’ve seen the 70% figure now. Is that also from Holgate?
John G. Bell,
It should be kept in mind that glaciers always melt eventually. Glaciers move, and they always flow downhill, either entering the ocean or warmer lowlands, where they melt.
It should also be remembered that glaciers grow and recede not because of the planet’s warming or cooling, but because of precipitation [or lack thereof] at higher altitudes.
That makes the 30% sea level rise due to glacier melt appear highly questionable. It could just as well be argued that the [very minor] seal level rise of the past century was due to precipitation, leaving out the glacier middle man. There are other causes besides glaciers and sea density. Had they said that fraction of sea level rise was due to general South polar ice shrinkage, or a decrease in global humidity and precipitation, it might have been defensible. But melting glaciers alone? Not likely.
The planet has been warming in fits and starts for ~11,000 years, ever since the end of the last great Ice Age — when Chicago was buried under a mile of ice. The sea level is still rising slightly as a direct result of the planet’s emergence from that Ice Age.
AGW has nothing measurable to do with the sea level. What is being described is entirely natural.
John,
Glacial ice can affect sea level. 35,000 years ago the sea level was hundreds of feet lower. Our current major sea ports would have been inland locations. But it is true that current glacial melt (for the ones that are retreating) is not going to cause a catastrophic increase in sea levels.
BTW…. To your list of causes for glacial ice loss don’t forget to add wind and landuse.
I addressed glaciers briefly in
The Story Of Glaciers
An excerpt..
The rest can be found here:
http://penoflight.com/climatebuzz/?p=88
I agree Smokey. Re: precip increasing ocean levels, I have wondered about the volume of water we are pumping out of the land-based aquifiers adding to the ocean volume. We’re pumping faster than the aquifiers can refill, it has to go somewhere and it doesn’t appear to be in the atmosphere either.
We are emptying aquifers but that may be more than offset by the lakes and reservoirs we create.
Yes, from Holgate.