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
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Is there any observational evidence that temperature lags CO2 at any scale?
The can of coke heated was used to prove runaway warming on NOW.
If the Earth was the can of coke, something had to have heated it to cause it to release so much CO2.
Passing dwarf star?
Hot arm of the Milky Way?
Intense cloud of radiation?
Nearby Supernova?
Big slowdown in Earth rotation rate (releasing stored energy)?
Incendiary comet swarm torching planet?
Highly elliptic orbit dwarf star getting close in (the Sun’s unknown companion)?
Sun in massive active overdrive?
Whatever it was 55 million years ago, we were NOT around.
Not even close by a factor of 10.
No mass extinction 55 million years ago, so an impact event is way down of the list. Maybe a swarm of meteorites, but then the evidence would be the layer along with the carbon.
How’s about a Carbon Meteorite?
NPR are citing this as a mechanism to heat the arctic. I think we can see how this will play out in the media …
http://www.npr.org/templates/story/story.php?storyId=5447575
I just saw the article and was going to drop a message to Doc. Watts. Anthony is tooooo fast.
2 things:
1) DUH!!
2) I expect RC to be in FULL DEFCON 1 RETALLIATION/DAMAGE CONTROL tomorrow….
Let’s see what scientists believe happened during this horrible time 55 million years ago. I am wondering where the now Arctic was during that time .. At any rate, it appears life made some major strides back then.
From: http://www.sdnhm.org/exhibits/mystery/fg_timeline.html
(San Diego Natural History Museum)
“Eocene Epoch
55-34 million years ago Plate tectonics and volcanic activity form the Rockies in western North America. Erosion fills basins. Continental collisions between India and Asia culminate in the Alpine-Himalayan mountain system. Antarctica and Australia continue to separate and drift apart.
The climate is subtropical and moist throughout North America and Europe. Early forms of horse, rhinoceros, camel, and other modern groups such as bats evolve in Europe and North America. Creodonts and ruminant ungulates evolve.
Archaic whales (archeocetes) evolve from terrestrial meat-eating ungulates. Sirenians (dugongs and manatees) first evolve in the shallow Tethys Sea.
Paleocene Epoch
65-55 million years ago During the Paleocene, the vast inland seas of the Cretaceous Period dry up, exposing large land areas in North America and Eurasia. Australia begins to separate from Antarctica, and Greenland splits from North America. A remnant Tethys Sea persists in the equatorial region. Mammalian life diversifies, spreading into all major environments. Placental mammals eventually dominate the land, and many differentiated forms evolve, including early ungulates (hoofed animals), primates, rodents, and carnivores. “
oops! I meant Antarctic.
Isn’t this just the same point that can be made from the ice core data?
The temperature changes in the Vostok ice core cannot be explained by the change in CO2 if 2CO2 leads to 3K.
Either 2CO2 is larger than 3K or… CO2 is not the main driver of temperature.
But…but…but!!! They told us the Science is Settled!!! [sarcasm off]
I love this one. Nothing like a good rebuke from a top-notch university.
Rice University is where the smart guys go.
The paleoclimate record of Temp vs CO2 tells us something very important about our climate and CO2. That is that CO2 is not a very sensitive driver of temperature and that in fact if anything it is temp that drives CO2. Of course though the alarmist will tell you that we are entering a dangerous period of CO2 driven warming. That is that our earth can tell the difference between natural CO2 and anthropogenic CO2 and it will react differently to smit us for our evil ways.
If I didn’t know any better, the conclusion one might draw is that if climate models only predict half the actual warming due to CO2, then the effect of AGW would be twice what is predicted…
Lot’s of ‘Death-trains” even back then…how dare they unsettle the settled science?
Leif,
That was my first thought, too.
Jim (18:53:56) :
NPR are citing this as a mechanism to heat the arctic. I think we can see how this will play out in the media …
Those people are “greenhouse” gases-obsessed. They cannot think in the real causes of warming, but only in their fabulous-“greenhouse” gases.
rbateman (18:50:20) :
How’s about a Carbon Meteorite?
——————————-
You’re giving AlGore’s some new ideas now, be careful… imagine having to pay taxes for ever single lil stone that lands on earth.
Smokey (19:18:00) :
Leif, That was my first thought, too.
so, why are people so happy about this? It would seem that AGW worse than anybody imagined is awaiting us…
Leif Svalgaard (19:14:39) : OK, so where’s the frapping warming then??
55 million years ago eh ?
Just proves Fred Flintstone did drive a Hummer through that Drive In restaurant for those giant ribs.
Leif Svalgaard (19:14:39) :
If I didn’t know any better, the conclusion one might draw is that if climate models only predict half the actual warming due to CO2, then the effect of AGW would be twice what is predicted…
Vaya! You’re right… I haven’t seen it that way. Perhaps they will adjust their models so the predicted temperature by doubling CO2 given by the models would be twice. It’s another AGW trick!!!
The same it’s happening with the NPR article cited by Jim (18:53:56)… They are cleaning the road before the race.
Leif,
It only shows how wrong their models are. Bill Illis’ chart makes clear that CO2 is not a causative agent regarding temperature.
Whatever caused the ancient warming,Could we be looking at the fact that the
warmer seas could hold less Co2?
I find it hard to compare the anomalies of NOAA, Unisys, and the SST of Marine Weather. NOAA shows us that the warmest anomaly is on the west coast of South America with the anomaly droping off the the west. While Marine Weather shows us Cooler water off the coast with warmer water off to the West. It looks like the wind is pushing water to the west not to the east like I thought El Nino is reported to do. Cooler water is still moving north in South America and lots of winter left down south.
While at it, what is up with all that cool water between Labrador and Greenland? It is 2-4 degrees below normal and Marine Weather shows it at 2-4 degrees C. Hudson bay is siting around 1 degree C on we are nearly halfway through July.
We are so happy, Leif, because it says that the Earth’s temp should be .7 C hotter than it is now…or was in 1998. It means they are looking at thier models closely and discovering that in order to force the feedback, the CO2 has to act like a one-way filter, and the Earth should look like Venus.
But it’s not.
So much for the global warming.
The PETM came and went. Whatever caused it left no traces (so far).
Which is why I would primarily suspect an interplanetary interloper of unknown origin, and secondarily suspect that the Sun went wild with high activity.
We have no better answer than a list of suspects then, and now.
The problem with rejiggering the climate models to show more sensitivity is that they will be in more trouble when it comes to explaining the current cooling.
The warmists are so…. (begins with an “S”)
the_Butcher (19:20:40) :
Ask not for whom the Carbon Meteorites fall, they fall for you.
Ideas for Gore? No, but if it’s true, I have some advice for Gore: Dump the luxurious mansion and get a cave.
Hmmm….. as I have wondered before. Why exactly were they in caves?
Didn’t know how to make huts? I doubt it.
Only hermits and monks live in caves.
Nobody lives in caves. So what were they doing in there?