Ancient global warming was jarring, not subtle, study finds

Los Angeles Times ^ | January 5, 2007 | Robert Lee Hotz

[presidio9]

Foreshadowing potential climate chaos to come, early global warming caused unexpectedly severe and erratic temperature swings as rising levels of greenhouse gases helped transform Earth, a team led by researchers at UC Davis said Thursday.

The global transition from ice age to greenhouse 300 million years ago was marked by repeated dips and rises in the amount of carbon dioxide in the atmosphere and wild swings in temperature, with drastic effects on forests and vegetation, the researchers reported in the journal Science.

"It was a real yo-yo," said UC Davis geochemist Isabel Montanez, who led researchers from five universities and the Smithsonian Museum of Natural History in a project funded by the National Science Foundation. "Should we expect similar but faster climate behavior in the future? One has to question whether that is where we are headed."

The provocative insight into planetary climate change counters the traditional view that global warming could be gradual and its regional effects easily anticipated.

Over several million years, carbon dioxide in the ancient atmosphere increased from about 280 parts per million to 2,000 ppm, the same increase that experts expect by the end of this century as remaining reserves of fossil fuels are burned.

No one knows the reason for so much variation in carbon dioxide levels 300 million years ago, but as modern industrial activity continues to pump greenhouse gases into the air at rapid rates, the unpredictable climate changes that took millions of years to unfold naturally could be compressed into a few centuries or less today, several experts said.

Carbon dioxide levels last year reached 380 ppm, rising at almost twice the rate of a decade ago, experts said. Average global temperatures have been rising about 0.36 of a degree Fahrenheit per decade for the last 30 years.

Still, the transformation

[Izzy Dunne]

Foreshadowing potential climate chaos to come, early global warming caused

Past performance is not indicative of future results.

[presidio9]

Stupid Dinosaurs. Wiped themselves out buring fossil fuels, only to become fossils themselves.

[Wuli]

".....Average global temperatures have been rising about 0.36 of a degree Fahrenheit per decade for the last 30 years."

But have not risen further since 1998. And actually, the "average global temperatures" have been rising since before the turn of the century, before world industrialization took off. But no matter, it must have been all those logs people burned to keep warm.

[DustyMoment]

This still fails to explain why CO2 levels were higher in the first half of the 20th century, but overall temeperatures were cooler during the same period. I don't believe that they can correlate the data between CO2 and global temperature levels.

In addition, the average temperature rise of .36 degrees F per decade for the last 30 years is also untrue. Satellite temperature measurements have consistently shown the total temperature rise for the last galf of the 20th century was only .1 degrees F.

This article is simply riddled with misinformation and mis-statements.




(Uh-oh, here it comes!)

[dynoman]

Actually in many cases the CO2 increase was after a temperature increase.

<<<-------longer ago --------- more recent-------->>>
<<<------Temperature --------- CO2------->>> ------------------------------------------------------------------------------------------------------------------------------------

<<<-------more recent --------- longer ago-------->>>
<<<------CO2 --------- Temperature------->>>

[grobdriver]

The global transition from ice age to greenhouse 300 million years ago was marked by repeated dips and rises in the amount of carbon dioxide in the atmosphere

Those damn cave men and their cars.... I mean... opps.

[dynoman]

what I should say is - "a CO2 change was after a temperature change."

[Froufrou]

Oh. Well, I knew that from the opening scenes of "Ice Age."

[Argus]

George Bush was around 300 million years ago? That guy is truly amazing.

[Bloody Sam Roberts]

I find it comical that a scientist is trying to explain the current, alleged, global temperature swing by juxtaposing human civilization with geologic time frames.

Whether it was 300 million years ago or 300 days ago, no human can easily comprehend a process that takes hundreds of thousands...or even thousands of years to manifest.

[cpdiii]

Carbon dioxide levels last year reached 380 ppm, rising at almost twice the rate of a decade ago, experts said. Average global temperatures have been rising about 0.36 of a degree Fahrenheit per decade for the last 30 years.

Not true

[presidio9]

I prefer the nutballs who say "global warming" is caused by methane from cow farts. These are the same lunatics who get tears in their eyes talking about how the plains were black with buffalo before whitey came along and killed them all for their hides. Nope, no disconnect with logic there.

[Obadiah]

...the same increase that experts expect by the end of this century as remaining reserves of fossil fuels are burned.

That's a MSM two-fer! Global warming is going to kill us, AND we're running out of oil!!

[Rurudyne]

Stupid Dinosaurs. Wiped themselves out burning fossil fuels, only to become fossils themselves.

Unless I'm mistaken, 300 million years ago was well before the age of Dinosaurs––in the Paleozoic.

As for an increase in CO2 during this time, how are these estimates being produced?

There are no ice cores from that era to trap 300 million year old bubble of air so the only thing I can imagine is they are somehow inferring atmosphere from sedimentary rock.

P.S. As for Dinosaurs and global warming, it is now believed that the quality of plant food made fermentation (a tactic used by cows––some of which can sustain a flame) a common necessity to extract value from low-quality plants. As fermentation gains efficiency as scale increases, a big stomach means a big, hungry dinosaur.

But pray tell imagine a 35 to 60 ton cow?

The sheer quantity of fart gas (methane) would have been staggering and such is considered a component of global warming. Add in the termites and more oxygen in the atmosphere and it's easy to see how there could be herd die offs––one lightning strike at the wrong time/place and instant firestorm.

[dynoman]

I can't believe how the entire premise of global warming caused by CO2 increase has been so easily sold to the public. One of the teams involved with the ice core CO2/temperature data was led by French expert Dr. Nicholas Caillon. Here is a link to their research paper;

Timing of Atmospheric CO2 and Antarctic Temperature Changes Across Termination III

In it are tidbits like this;

"The analysis of air bubbles from ice cores has yielded a precise record of atmospheric greenhouse gas concentrations, but the timing of changes in these gases with respect to temperature is not accurately known because of uncertainty in the gas age-ice age difference. We have measured the isotopic composition of argon in air bubbles in the Vostok core during Termination III (-240,000 years before the present). This record most likely reflects the temperature and accumulation change, although the mechanism remains unclear. The sequence of events during Termination III suggests that the CO2 increase lagged Antarctic deglacial warming by 800 ± 200 years and preceded the Northern Hemisphere deglaciation."

"This confirms that CO2 is not the forcing that initially drives the climatic system during a deglaciation. Rather, deglaciation is probably initiated by some insolation forcing (1, 31, 32), which influences first the temperature change in Antarctica (and possibly in part of the Southern Hemisphere) and then the CO2. This sequence of events is still in full agreement with the idea that CO2 plays, through its greenhouse effect, a key role in amplifying the initial orbital forcing. First, the 800-year time lag is short in comparison with the total duration of the temperature and CO2 increases (~5000 years). Second, the CO2 increase clearly precedes the Northern Hemisphere deglaciation."

The Caillon team paper goes on to mention a delay of 800 years "seems to be a reasonable time period to transition from an initial Antartic temperature increase into a CO2 atmospheric increase though oceanic processes". The mechanism might be "a change in vertical ocean mixing", consistent with "a process that involves the deep ocean as its mixing time is close to the observed 800 year lag". They offer cryptic comments like "sequence of events is still in full agreement with the idea that CO2 plays, through its greenhouse effect, a key role in amplifying the initial orbital forcing. "

Ok an "idea", what's that? The absolute objective truth? "The radiative forcing due to CO2 may serve as an amplifier of initial orbital forcing, "

"May"?? What's that, the absolute objective truth?

"Initial orbital forcing"?? What's that? Temperature increasing first?

One more thing the Caillon paper states is that the the 800 year lag cannot rule out any of these mechanisms - "vertical ocean mixing, sea-ice cover changes, or a biological mechanism such as atmospheric dust flux or ocean productivity" - as having sole control of CO2 outgassing.

"Sole control", how about that?

[Obadiah]

The sheer quantity of fart gas (methane) would have been staggering and such is considered a component of global warming. Add in the termites and more oxygen in the atmosphere and it's easy to see how there could be herd die offs––one lightning strike at the wrong time/place and instant firestorm.

SO THAT'S IT! That's the BIG BANG Theory in a nut shell! The copious amounts of methane gas from dinosaurs ignited the big bang when lightning struck.

Sheer genius!

[oncebitten]

Does anyone realize how large an SUV would have been required to carry 6 full-grown brontosaurs? I have estimated the size of the engine at 3000 cubic inches with 5000 horsepower - and that does not even count the turbos. Typical milage was .10 per gallon and they did not even have catalytic converters.

[presidio9]

Unless I'm mistaken, 300 million years ago was well before the age of Dinosaurs––in the Paleozoic.

Sorry professor.

Stupid trilobites.

[Rurudyne]

More Dresden than Hiroshima, but you've got it.

Or as one friend of mine put it when he read a longer explanation: "That's just WRONG!"

I always think of Henry Blake's quote from the M*A*S*H episode: "It just went 'boom.'"