Global warming: Our best guess is likely wrong
No one knows exactly how much Earth’s climate will warm due to carbon emissions, but a new study this week suggests scientists’ best predictions about global warming might be incorrect. The study, which appears in Nature Geoscience, found that climate models explain only about half of the heating that occurred during a well-documented period of rapid global warming in Earth’s ancient past. The study, which was published online today, contains an analysis of published records from a period of rapid climatic warming about 55 million years ago known as the Palaeocene-Eocene thermal maximum, or PETM.
“In a nutshell, theoretical models cannot explain what we observe in the geological record,” said oceanographer Gerald Dickens, a co-author of the study and professor of Earth science at Rice University. “There appears to be something fundamentally wrong with the way temperature and carbon are linked in climate models.”
During the PETM, for reasons that are still unknown, the amount of carbon in Earth’s atmosphere rose rapidly. For this reason, the PETM, which has been identified in hundreds of sediment core samples worldwide, is probably the best ancient climate analogue for present-day Earth.
In addition to rapidly rising levels of atmospheric carbon, global surface temperatures rose dramatically during the PETM. Average temperatures worldwide rose by about 7 degrees Celsius — about 13 degrees Fahrenheit — in the relatively short geological span of about 10,000 years.
Many of the findings come from studies of core samples drilled from the deep seafloor over the past two decades. When oceanographers study these samples, they can see changes in the carbon cycle during the PETM.
“You go along a core and everything’s the same, the same, the same, and then suddenly you pass this time line and the carbon chemistry is completely different,” Dickens said. “This has been documented time and again at sites all over the world.”
Based on findings related to oceanic acidity levels during the PETM and on calculations about the cycling of carbon among the oceans, air, plants and soil, Dickens and co-authors Richard Zeebe of the University of Hawaii and James Zachos of the University of California-Santa Cruz determined that the level of carbon dioxide in the atmosphere increased by about 70 percent during the PETM.
That’s significant because it does not represent a doubling of atmospheric carbon dioxide. Since the start of the industrial revolution, carbon dioxide levels are believed to have risen by about one-third, largely due to the burning of fossil fuels. If present rates of fossil-fuel consumption continue, the doubling of carbon dioxide from fossil fuels will occur sometime within the next century or two.
Doubling of atmospheric carbon dioxide is an oft-talked-about threshold, and today’s climate models include accepted values for the climate’s sensitivity to doubling. Using these accepted values and the PETM carbon data, the researchers found that the models could only explain about half of the warming that Earth experienced 55 million years ago.
The conclusion, Dickens said, is that something other than carbon dioxide caused much of the heating during the PETM. “Some feedback loop or other processes that aren’t accounted for in these models — the same ones used by the IPCC for current best estimates of 21st Century warming — caused a substantial portion of the warming that occurred during the PETM.”
Source: Rice University
Oops, I missed two inter-related ones in additon to the others I already posted, sorry!
The other thing I’d meant to ask was about ‘warmer’ temperature conditions. My understanding was that it during historical time periods when the earth was warmer than present day, flora and fauna seemed to flourish — .e.g., almost certainly more life, plants, and animals on average than during cooler periods. IF that’s correct, how is the IPCC et. al, justifying all the claims of deserts, water shortages, decreased life overall, etc.
Next, for warmer temperature effects…. suspect I’ll feel very silly when someone answers this one for me… but doesn’t one have to look to the tropics and see rain forests and massive amounts of life and diversity? Seems an apparent disconnect to me, present day warm often results in vastly more life, but theoretical warm = death and drought? Obviously location relative to oceans, mountain ranges, atmospheric jet stream etc., have huge impact on the issue, but in general….. ??
Help please? (15:16:57) :
The other thing I’d meant to ask was about ‘warmer’ temperature conditions. My understanding was that it during historical time periods when the earth was warmer than present day, flora and fauna seemed to flourish -e.g., almost certainly more life, plants, and animals on average than during cooler periods. If that’s correct, how is the IPCC et. al, justifying all the claims of deserts, water shortages, decreased life overall, etc.
During geological eras biodiversity reaches higher numbers than during cooling periods. As the surface is warmed up by the incident solar radiation, evaporation and cloudiness increase, so in general rainfalls tend to increase. I see all climate changes are natural until present. I have talked about ecological succession many times; some species are displaced by other species, but that does not mean “extinction” but change, i.e. succession. I think the term has been extremely abused by environmentalists for scaring people through showing them local “extinctions” of such or that species, when in reality those species are fluorishing abundantly at other locations.
For example, after fire in a taiga, the land finishes almost devastated. In the natural way of recovery, there will not be production of conifers immediately after the devastation, but organisms which can prosper under extreme conditions like drought, low levels of nutrients in soil, dragging by winds and water, etc.; for example, lichens and photosynthetic bacteria. Lichens and photosynthetic bacteria restore the best part of fertile soil which had been lost by the fire until ferns and mosses. When soil restoration has almost concluded, some weeds start populating the area; grass, herbs and scrubs for example. The humus layer must have been restored completely so that trunk plants can grow there. If there are survivors of native trees, their seeds could be transported by currents of air or water, or carried by animals, so the same species of trees could appear again populating the area. This can be completed in decades, centuries or millennia.
Next, for warmer temperature effects…. suspect I’ll feel very silly when someone answers this one for me… but doesn’t one have to look to the tropics and see rain forests and massive amounts of life and diversity? Seems an apparent disconnect to me, present day warm often results in vastly more life, but theoretical warm = death and drought? Obviously location relative to oceans, mountain ranges, atmospheric jet stream etc., have huge impact on the issue, but in general….. ??
Unfortunately, tropical rainforest is the most easily broken biome in terms of recuperation.
This type of conclusion happens when rising CO2, an effect, is confused as a driver and modeled as such.
As the measured radiation from the SUN is insufficient to explain the Earth Temperature observations, something else is at work.
The Earth’s temperature (not the temperature of the thin film of atmosphere) is modulated by the electrical currents entering it from the sun and solar system. The electrical force is the one force totally ignored by mainstream geoscience and climate as having any contribution to make to Earth dynamics.
Ammendment: “During geological eras biodiversity reaches higher numbers than during cooling periods.”
It should have said:
“During periods of warming through geological eras biodiversity reaches higher numbers than during cooling periods.”
Tom P (10:52:06) :
The paper did model the PETM climate
Tom P (13:29:52) :
This can by no stretch of the imagination be described as running a model or even a fit, so where is the confusion?
The confusion is showing in the discrepancy between your two statements.
Neven (12:48:29) :
At first I thought Leif Svalgaard (who is one of the main reasons for me to come to WUWT on a daily basis) was being ironic, but seeing later on in the discussion that he isn’t, has left me feeling a bit uneasy.
What I’m saying is that the article can be read two ways: as many here did [cheering] and as support for AGW [the paper does support a significant increase (half of the total) due to CO2].
Typical example of the blindness caused by people with an agenda [or strong opinion], where they only can see what supports their own view, combined with the confusion about what a model is [see above]. As I indicated in an earlier comment there is a big difference between the GCM that people run a century ahead [which may be silly], and the simple sensitivity modelling [which is perfectly sensible – although one can quibble over details]. So when people say ‘the model don’t work’ are they sure they know which of the two they are talking about.
To me, the [partly unknown] differences between the conditions back then and now makes it dubious that one could expect an agreement to better than the factor of two they mentioned, and probably not even that good.
Nasif Nahle (13:44:46) :
We have observed at least four bodies of the solar system which simultaneously are undergoing climate changes.
I had my little granddaughter just now throw a coin, it only took her three trials to get four heads in row [slightly better than predicted]
The only common source of energy for climate in this solar system is… the Sun.
Same old tired argument. We are not talking about turning off the Sun, but about the variations of the climate.
And the simultaneous [and presumable in the same direction] climate changes on four planets is somewhat of a myth. Perhaps it is time to look at this in detail by digging up links to them. As far as I remember, the change in Uranus has to do with the polar axis lying in the orbital plane, so what we are seeing is a seasonal change [not a climate change]. the same for Neptune: “The relative “hot spot” is due to Neptune’s axial tilt, which has exposed the south pole to the Sun for the last quarter of Neptune’s year, or roughly 40 Earth years. As Neptune slowly moves towards the opposite side of the Sun, the south pole will be darkened and the north pole illuminated, causing the methane release to shift to the north pole” [wiki].
So, produce links/papers/evidence that what we see are climate changes and not seasonal changes [seasons on the outer planets are very long in Earth years].
I swear, I am not drunk. It’s just another correction:
“Lichens and photosynthetic bacteria restore the best part of fertile soil which had been lost by fire until ferns and mosses can grow again there.
This event lasted 20,000 years so what is left. Some kind of albedo related event, making the Earth’s surface darker? To get the required temp increase would mean dropping the albedo from 0.3 to 0.26 , that’s a lot of stagnant algal bloom in the sea?
It’s a unique event in the geological record. It is also extraordinarily short on geological timescales. Which means we have to look for something that could have only occured once.
The filling of the Arctic basin with relatively warm water through a narrow gap fits the bill. This happened to both the Black and Red Seas in recent geological times. So we know this kind filling of a previously empty below sea level basin is a regular occurance. The difference would have been the size of the Arctic basin and the fact it is at the N Pole.
Which leads to a paradoxical conclusion.
What appears to be an abrupt warming of the climate was caused by an abrupt cooling of the climate. As warm water poured into the Arctic Basin (and note this would have been warm surface water), massive quantities of heat and water vapour would have been dumped into the atmosphere.
For a short period the Earth’s atmosphere would have been much warmer and wetter with a large increase in the water vapour greenhouse effect. Plant growth would have increased dramatically. However, when the Arctic Basin filled and equilibrium was reached, the result would have been the Earth’s climate had lost a great deal of heat. The oceans and the atmosphere would become much colder (and much drier). A massive plant die off then occurs giving the CO2 spike.
This fits all the evidence I have seen. Also note the 20,000 years is due to the precision of the geological record. It could have happened in 1,000 years.
Leif Svalgaard (05:26:04) :
Drudge picked up the story
Thanks for the tip Leif !
@ur momisugly Leif…
You have left the kings of the story behind, Mars and Titan. Those bodies, a planet and a satellite, are not undergoing seasonal changes but climate changes. RC has overreacted before the news on the melting of polar caps on Mars because it is not a myth, but an “inconvenient” real thing. I never thought you could consider reality is a myth:
http://mars.jpl.nasa.gov/mgs/newsroom/20050920a.html
Regarding Titan, its liquid methane is melting, like in the old good times:
http://www.astrobio.net/index.php?option=com_retrospection&task=detail&id=2194
http://www.newscientist.com/article/mg20227115.400-will-summer-never-end-in-titans-south.html?DCMP=OTC-rss&nsref=saturn-and-its-moons
RE: rbateman (17:32:17) :
What else was going on 55 million years ago?
What about the extinction that occured 65 million years ago that is in a layer all over the place?
=========================
Indeed. That extinction resulted in a massive explosion of fungi. The fungi, combined with the sudden exposure of soil in areas with humid climates that were previously heavily covered by green plants, would have liberated a massive amount of methane and CO2 not to mention water. That incident is instructive in another way. Just prior to the extinction, CO2 levels were quite low … on par with what we currently have. I consider this a grave threat. Any serious interruption in photosynthesis at this low level of CO2 and we may have another great extinction on our hands. A big bolide may be all that’s required to crash the system. We have almost no margin right now, CO2 is so low green plants must be stressed and low functioning, relatively speaking.
Nasif Nahle (17:52:33) :
RC has overreacted before the news on the melting of polar caps on Mars
So Mars is getting warmer and the Earth is cooling all due to the Sun.
Regarding Titan, its liquid methane is melting
Hardly climate, as the Titan ‘year’ is 30 years long. This is just weather, and as your links suggest are due to Titan causes.
So, all in all, there is no good evidence for the myth that all planets change their climate in sync because of changing solar activity.
Leif alternative point of view seems rather shaky to me.
The climate models fail to predict even the most basic aspects of today’s climate, let alone thousands of years ago. The heating profile with altitude is wrong, the precipitation rates are wrong. Some effects like net forcing of clouds are likely the wrong sign entirely, the role of dust and soot and other factors like biological influences in the biosphere are almost entirely neglected. One just has to look at the past performance of future predictions to illustrate this point. I’m entirely on the side of Freeman Dyson with my confidence that these models are very poor at describing the climate.
And thus, here we are. Instead of seeing this for what it is – yet another illustration of how over-simplistic climate models fail to model the exceedingly complex biosphere, we instead try to claim that these flaws could be a sign that climate change is going to be far worse. Its amazing…while we accept that the predictions are 50% out, we never waiver in our believe of their validity but instead suggest scaling things up.
Fortunately, we still have empirical evidence to take heart in. There are many past CO2-temperature reconstructions that illustrate the same facts. Temperatures rise and fall in many cases irrespective of CO2 levels.
* The Cambrian period had CO2 levels at over 7000ppm with no runaway effect.
* The Ordovician period has CO2 levels at 4200ppm and a temperature varying from todays up to +7C.
* Carboniferous period…800ppm…temperature varying between +8C and todays.
Lots of variation, relatively weak forcing.
Then obviously you have the time delays in the icecores with temperatures leading CO2 which gives another clue on how significant CO2 is. Then you have the lack of correlation between temperatures and Co2 levels in the present century with temperature warming and cooling periods while CO2 levels are always increasing.
Why is it so hard to accept that CO2 effects on global temperatures have been drastically overstated by the likes of the IPCC?
I also wonder about the logic. We are at an age where in the past few hundred thousand years, the global climate has been on average bitterly cold. We have had many oscillations from iceage to a relatively short warm spell and back to ice age. We are at the tail end of a warm spell right now according to the Vostok data for example. It is very likely that we would of eventually dove back into an iceage. If anything, I wish global warming was true because a 4C rise is vastly more attractive than the long term icy alternative.
Privet Ein (19:41:16) :
The climate models fail to predict even the most basic aspects of today’s climate, let alone thousands of years ago.
I think you, too, are confusing the two kinds of models
are 50% out, we never waiver in our believe of their validity but instead suggest scaling things up.
The model referred to in the paper is NOT the silly GCMs that people use to ‘predict’ the climate, but the other kind of model, that just is used to determine the sensitivity of the climate system to forcings.
As I now have said umpteen times, people’s blindness arising from their viewpoints allow this paper to be interpreted both ways, and on balance, the paper thus is not a useful contribution to the debate.
Leif Svalgaard (19:36:40):
So Mars is getting warmer and the Earth is cooling all due to the Sun.
The note on Mars’ climate change was released in 2005.
Hardly climate, as the Titan ‘year’ is 30 years long. This is just weather, and as your links suggest are due to Titan causes.
Weather all over a hemisphere of the satellite? Here a fragment from the article:
“These southern clouds are thought to be caused by convection in Titan’s atmosphere, driven by the heat of the sun. They were expected to disappear as Titan’s southern summer draws to a close, before reappearing in the northern hemisphere soon after.” (bolds are mine)
However, they didn’t disappear and the southern summer prolonged beyond model predictions:
“However, the latest analysis of Cassini observations shows that the southern clouds have not budged. “Titan’s meteorology is still active in late summer, which does not agree with climate model predictions…”
So, all in all, there is no good evidence for the myth that all planets change their climate in sync because of changing solar activity.
There are not observations on all planets, only on four planets, including Earth, one planetoid and two satellites, which does not exclude the fact that other bodies’ climates are changing.
Neven (14:59:16) :
“Even if it did all escape and cause a climate change it would still not be AGW. ”
Well, that’s a relief!
Absolutely! You get my point though? All this carfuffle – and how Gore has made his $100 million so far and counting fast – is on the premise that humans are causing global warming. Most of the contributors here on WUWT don’t think that we are. But also most of us do not argue that climate changes. It’s never stable.
I’m a geologist and I grew up looking at rocks in Scotland which are more than 1 billion years old which were deposited when Scotland was a hot and arid desert. I can’t say where ‘Scotland’ was relative to the equator 1 billion years ago but it was hot and dry. (At one of my favourite localities in the north west highlands of Scotland there are some lacustrine mudstones which have desiccation cracks in them and also raindrop impressions. I like to think that the raindrops fell at 14:37 on a Tuesday afternoon, 17th October , 1,000,000 Before Present.) Climate also isn’t just about temperature. There are many more factors that make up climate and weather. The weather forecast shouldn’t just be : “it will be 20C (70F) tomorrow. It should also state that it will be 20C tomorrow, there will be 80% cloud cover, the humidity will be 80%, the wind will be from the north east at 18 mph backing northwest and increasing to 25mph, the pressure will drop from 1000mb to 990mb from midnight to midnight – and at an increasing rate.
I can look at pretty much any sample of a sedimentary rock and give you my opinion of in which of a myriad of depositional environments it was deposited – subaerial – submarine – shallow marine – deep marine – intertidal – storm deposit – swamp – etc. etc. Now – I could bullshit you. Were I to do so, I wouldn’t be the first geologist so to do. But I, personally, could not do that out of personal integrity. Furthermore, I can look at – say 1 metre – of sedimentary rocks and say how the depositional environment changed over that 1 metre – or 100 metres or kilometers… I may also be able to say whether or not there had been a major volcanic eruption, earthquake, ice age, possibly even meteorite impact event, during the deposition of the said 1 metre, 10 metres, 100m, 1 km or whatever. I’ve seen lots of good examples in sedimentary rocks of where sea level has risen by appreciable amounts – say up to at least 50m – over a very short (geologically) space of time. Likewise I’ve seen where sea level has fallen – although this is less common in the rock record as sea level fall is usually accompanied by erosion. The thing with rocks is that we can always go back and look at them again and confirm – or change – the interpretation.
One of the best tools in dating rocks, or in correlating rocks of similar age in different parts of the world, is by biostratigraphy. Biostratigraphic analyses also show that depositional environments change over time – sometimes extremely rapidly. Species abundance and biodiversity also changes in response to changes in depositional environment. And it is all natural. We are njust one species on this earth – we have adapted in the past and will adapt in the future. At some time we will become extinct.
And what really gets me going is that politicians, con men and pseudoscientists have been getting away with this scam of AGW for so long and now they want us to pay even more of our hard earned money so as they can continue to feather their own nests.
If you have the time and a fast connection, verify that the warming on Mars started off in 1998; coincidence?
http://www.nasa.gov/mov/133955main_mgsweb-cc.mov
Nasif Nahle (20:24:39) :
The note on Mars’ climate change was released in 2005.
And pertains to the change since 2002. You call that climate? And how much did the Sun [TSI] increase from 2002 to 2005?
However, they didn’t disappear and the southern summer prolonged beyond model predictions
Just shows that we don’t understand seasons on Titan yet. And again, how much did the Sun’s output increase to ‘explain’ the melting?
So, all in all, there is no good evidence for the myth that all planets change their climate in sync because of changing solar activity, and, in particular, that the scattered observations of weather and seasons on some of them support such a view.
Bill Illis (18:20:27) :
I have charted the temp vs CO2 data over this period and there is really a poor correlation between the two. This chart also shows the important continental drift timelines which are fundamental to understanding this climate period.
http://img20.imageshack.us/img20/2464/tempvsco267m.png
Thank you for this. It shows that CO2 starting levels were 800ppm and end levels also 800ppm. In the “spike” temperature changed by 2.5 degrees, at least in this plot.
What guarantees that the functional relation of CO2 to temperature ( either lagging or leading) is linear and the absolute value has no effect? Out gassing from oceans I guess is linear, but am no chemist and am not sure, at least the function is known. All other possible CO2 sources come chaotically from highly complex systems and will be chaotic in output, that is highly non linear.
To get a sensitivity relevant to our value of 384 or so ppm doubling we would need that functional form .
The only known functional form is for out gassing from the heating oceans and is worthless for supporting an AGW argument as it lags. If use is to be made of this paper’s sensitivity in favor of AGW to bring it down for use to 300ppms it will be pure guess work. Of course climatologists excel in guesswork. They also excel in seeing the world as linear and ignoring logic.
I guess geologists have caught the linear bug from climatologists.
Doubling of atmospheric carbon dioxide is an oft-talked-about threshold, and today’s climate models include accepted values for the climate’s sensitivity to doubling. Using these accepted values and the PETM carbon data, the researchers found that the models could only explain about half of the warming that Earth experienced 55 million years ago.
Even if the sensitivity used in the GCMs were correct, which it is not as the last ten years temperatures vs CO2 show, the only conclusion could be that no linear extrapolation of current guessed sensitivities can explain the PETM CO2/tempearature maximum. No conclusion can be made for our current sensitivities for the same reasons.
Nasif Nahle (20:38:25) :
If you have the time and a fast connection, verify that the warming on Mars started off in 1998; coincidence?
Then the warming goes against the cooling that skeptics posit has happened on Earth the last decade…
So, all in all, there is no good evidence for the myth that all planets change their climate in sync because of changing solar activity.
So, all in all, there is no good evidence for the myth that the Earth changes its climate because of changing CO2 levels.
The amount of CO2 in the atmosphere cannot affect the temperature of the oceans (except through some effect it may have on cloudiness, although surely water vapour is a more important factor here – by an enormous amount). The thermal state of the oceans determines the “average” temperature of the atmosphere and “on average”, aka, “crudely”, the amount of CO2 in the atmosphere. CO2 concentration can never effect the average temperature of the atmosphere for anything more than a short time, slowing, as it clearly does by a small amount, the amount of heat that can escape from the oceans into the cold vacuum of space. But it is the heat content of the oceans that matters (leaving out plate tectonics over millions of years but CO2 is irrelevant here, too), and no-one has ever described a mechanism by which CO2 concentration in the atmosphere can effect this. This is a very simple argument. Why are we bothering with this C02 nonsense? It is only “good” at this point, as it may inhibit the onset of the next glacial period for a short time by slowing the loss of the heat that has, through an unknown process, been pumped into the oceans since the LIA. This, the terrifying reality of the ice age, is the only climatic change we should be thinking about. Can we stop the onset of the next glacial period of the current ice age? If we could, this would be the greatest boon to life on earth! We would then, truly, have saved the planet – at least in the sense of preventing a decline in the biomass of, what, 60-70% ?
Leif,
You missed my correction (11.11.12). This paper did NOT model the PETM climate.
As for Martian climate change, this is primarily driven by Milankovitch cycles, which due to the increased eccentricity and lack of lunar stabilisation have a stronger effect than on Earth.
anna v (21:16:07) :
What guarantees that the functional relation of CO2 to temperature ( either lagging or leading) is linear and the absolute value has no effect? Out gassing from oceans I guess is linear, but am no chemist and am not sure, at least the function is known. All other possible CO2 sources come chaotically from highly complex systems and will be chaotic in output, that is highly non linear.
Anna, the paper you brought to my attention earlier (thank-you) indicates that oceanic CO2 evolution is highly non-linear and chaotic, remember?
http://www.whoi.edu/page.do?pid=12457&tid=282&cid=45946
The plankton try to protect themselves by producing a chemical compound called DMSP, which some scientists believe helps strengthen the plankton’s cell walls. This chemical gets broken down in the water by bacteria, and changes into another substance called DMS.
DMS then filters from the ocean into the air, where it breaks down again to form tiny dust-like particles. These tiny particles are just the right size for water to condense on, which is the beginning of how clouds are formed. So, indirectly, plankton help create more clouds, and more clouds mean that less direct light reaches the ocean surface. This relieves the stress put on plankton by the Sun’s harmful UV rays.
DMS levels peak from June through the end of September. Surprisingly, plankton levels are at a minimum during this time. That means that the number of plankton does not affect how much DMS they produce. During the summer, the study found that a whopping 77 percent of the changes in amounts of DMS were due to exposure to UV radiation. The researchers found it amazing that a single factor could have such a big affect on this process.
And how much does the Sun’s UV production vary?
Two carbons/DMS: then conversion of DMS to DMSO then to CO2
http://umbbd.msi.umn.edu/sulf/sulf_map.html
Other DMS data
http://gradworks.umi.com/33/02/3302968.html
http://www.msmaustralia.com.au/articles/mainmsm.html
Although I am still not at liberty to discuss this in detail due to ongoing proprietary considerations, DMSO has a positive growth regulatory effect on terrestrial plants, as does polyvinyl pyrrolidone.
Tim Clark (04:41:02):
I should explain why PVP is involved in this process, but I can’t. If interested, follow this line of investigation:
http://www.patents.com/Agents-regulating-plant-growth/US4948415/en-US/
http://www.freepatentsonline.com/y2009/0169924.html
Anthony
Somebody above mentioned the limited number of posts on Roger Pielke Jr’s web site.
I have tried to post and I am not sure which account to use? It may be standard in the US but in the UK it is either like your site or Climate Audit’s or you register. It may be helpful if Roger placed and explanation for dummies like me.
Best Regards