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Study blames human activity for climate change

NASA and international university researchers claim that humans have thrown off the balance between the Earth's rotation, surface air temperatures and movements in its molten core through our contribution of greenhouse gases.

Those included in the study were Jean Dickey and Steven Marcus from NASA's Jet Propulsion Laboratory, along with Olivier de Viron, from the Universite Paris Diderot and Institut de Physique du Globe de Paris in France.

It is well known that an Earth day consists of 24 hours, which is the time it takes for the Earth to make one full rotation. Over a year's time, seasonal changes occur due to energy exchanges between fluid motions of the Earth's atmosphere, the oceans and solid Earth itself, which changes the length of a day by about 1 millisecond. In addition, the length of a day on Earth can vary over longer timescales such as interannual timescales (two to 10 years) or decadal timescales (10 years).

But Earth’s oceans or motions of its atmosphere cannot explain the variances in the length of day over longer timescales. Instead, longer fluctuations are explained by the flow of liquid iron within Earth's outer core, which interacts with the mantle to determine Earth's rotation. This is also where the Earth's magnetic field originates, and because researchers cannot observe the flows of liquid iron directly, the magnetic field is observed at the surface.  

Studies have shown that this liquid iron "oscillates in waves of motion that last for decades," and have timescales that resemble long fluctuations in Earth's day length. At the same time, other studies have shown that long variations in Earth's day length are closely related to fluctuations in Earth's average surface air temperature. 

In this study, the NASA/university team of researchers has linked Earth's rotation, surface air temperatures and the movement in its molten core. They did this by mapping existing data on yearly length-of-day observations and fluid movements within Earth's core against "two time series of annual global average surface temperature." One dated back to 1880 from NASA's Goddard Institute of Space Studies in New York, and the other dated back to 1860 from the United Kingdom's Met Office.  

According to the study, temperature changes not only occur naturally, but are also affected by human activities. So researchers used computer climate models of Earth's oceans and atmosphere to generate changes made by humans. Then, these temperature changes caused by human activities were removed from the overall total observed temperature records. What they found was that old temperature data coordinated with data on Earth's day length and movements of its core until 1930, but after that, surface air temperatures increased without corresponding changes in movements of the core or day length. According to the study, this deviation after 1930 is linked to increased levels of the human contribution of greenhouse gases.  

But the new temperature data that the researchers generated (which subtracted human activity from the equation) had a temperature record that coordinated with Earth's core movements and day length, showing how human activity has thrown the Earth's climate off balance. 

"The solid Earth plays a role, but the ultimate solution to addressing climate change remains in our hands," said Dickey. 

Dickey is unsure as to why these three variables correlate, but hypothesized that Earth's core movements might interfere with the magnetic fielding of charged particle fluxes, which may affect cloud formation. This affects how much sunlight the Earth absorbs and how much is reflected back into space. 

"Our research demonstrates that, for the past 160 years, decadal and longer-period changes in atmospheric temperature correspond to changes in Earth's length of day if we remove the very significant effect of atmospheric warming attributed to the buildup of greenhouse gases due to mankind's enterprise," said Dickey. "Our study implies that human influences on climate during the past 80 years mask the natural balance that exists among Earth's rotation, the core's angular momentum and the temperature at Earth's surface." 

This study was published in the Journal of Climate.

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By docawolff on 3/14/2011 2:24:04 PM , Rating: 1
Dickey is unsure as to why these three variables correlate, but hypothesized that Earth's core movements might interfere with the magnetic fielding of charged particle fluxes, which may affect cloud formation. This affects how much sunlight the Earth absorbs and how much is reflected back into space.

Not exactly "no idea..." and not exactly "no hypothesis..."

By Schrag4 on 3/14/2011 2:33:22 PM , Rating: 1
Yes but the impression I got when reading this was that the study used the assumption that humans caused change to prove that humans caused change. Did the article read this way for anyone else? Maybe it's just me...

By kattanna on 3/14/2011 3:51:26 PM , Rating: 1

starting off with blame didnt seem overly professional to me.

but im not sure if it came from the actual study paper, or the person who actually wrote the article at science daily, which tiff just about copied word for word

the papers abstract doesnt have that blame up front

on another note: i do find it interesting that they managed to find earth based cycles affecting climate. that to me was the real news that is getting lost in the "blame game"

By phxfreddy on 3/14/2011 5:40:09 PM , Rating: 3
Responsible Environmentalist Terrans Against Reprehensible Debacles

Won't you please join??? Don't be a denier!

By JediJeb on 3/14/2011 9:13:37 PM , Rating: 2
This group probably also supports PETA since cow farts are a major cause of global warming. Please support People for the Eating of Tasty Animals, it will help us alleviate this very serious problem. PETA, saving the planet one burger at a time.

By Divineburner on 3/14/2011 6:49:20 PM , Rating: 5
Exactly. That's what I thought when I read this article too.


When I read the abstract of the paper in question ( I have no subscription), I see nothing that means even close to what this article is implying.

Quoting from the extract:
It is shown here that 1) the correlation among these three quantities exists until 1930, at which time anthropogenic forcing becomes highly significant; 2) correcting for anthropogenic effects, the correlation is present for the full span...

Yes, a correlation after anthropogenic factors are removed.

As well as the final sentence of the abstract:
In all three cases, their signals would be much smaller than the anthropogenic greenhouse gas effect on Earth’s radiation budget during the coming century.

Which obviously states that man made global warming outweigh the effects from Earth's core and Length of Day.

This paper checks the Length of the Day, Surface Average Temperature and Core Angular Momentum, and discovers a curious correlation that need to be addressed in further studies. This is nothing out of ordinary. You first find a phenomenon, then you attempt to explain it.

It's people like that author of this "news" (read: Tiffany Kaiser) that intentionally mislead the reader as to the original intent of the article and gives science a bad light.

By geddarkstorm on 3/14/2011 5:10:42 PM , Rating: 3
No, that's speculation, no matter what they want to call that, it's pure hand waving and conjecture. There is no friggin way the surface temperature of Earth, within the range of natural variability, is going to affect rotational speed.

However, what about the other way around? What about the frictional heat generated by the core and the mantle? Might THAT affect surface temperature of the Earth? Wouldn't that not only make senses, but follow the laws of physics that the other way would likely be breaking?

What makes more sense?

By Lexda on 3/15/2011 11:44:04 AM , Rating: 2
Tell me again why you believe "there's no friggin' way?" If you're trying to show an aura of competence regarding science, you're doing it wrong. I mean, personally, there's no friggin' way a bowling ball and a golf ball will fall at the same rates; it just doesn't make sense!

"The greatest words ever uttered by a scientist aren't 'Eureka!" but rather, 'Now that's funny...'"

Science isn't about proclaiming "But that's impossible!" It's about figuring out why something we previously thought was impossible actually occurs.

By geddarkstorm on 3/15/2011 5:34:56 PM , Rating: 2
They have absolutely no mechanism. Nor is there any mechanism in physics I know of. Perhaps I'm wrong, but think about heat transfer for a minute and spin dynamics between a solid and a fluid. Then look at the orders of magnitude difference between small fluctuations of 10C on the surface of the planet between the mass and temperature of the core/mantle.

Use your head for a second.

Now, what about the other direction? Could changes in the MASSIVE core of our planet rubbing against the MASSIVE mantle, affect within a few tenths of a degree C the temperature of the surface? Think for a minute, and do some empirical experiments of your own instead of of just swallowing whatever you're spoon fed.

As to your example, empirical evidence quickly showed they did fall at the same rate, nor was there no obvious violation of physics that would preclude them to do so, or any opposite, and far more likely mechanism. So don't go spouting off cliches without actually thinking about the issue.

By Lexda on 3/15/2011 6:16:02 PM , Rating: 2
I'm not trying to offer an explanation. I'm simply noting that all of my scientific training has taught me to not discard something simply because it doesn't meet my preconceptions.

By RedemptionAD on 3/16/2011 1:56:20 AM , Rating: 2
The law of probability says that nothing is impossable. It's just a matter of is it probable. No exceptions.

By geddarkstorm on 3/17/2011 1:17:49 PM , Rating: 2
And scientific training says outlandish speculation requires outlandish proof before it's anything more than. Or, that to be science in the first place, it must be testable. There's nothing testable about this, so it can't even be considered science. On the other hand, what we do know of physics contradicts this.

Could it be real? As the other person who replied to you said, of course; and our overarching theories get modified and changed by discoveries every year. But probable? No way. So should we freak out and start talking about this as if it were fact? NO. And that's where the danger lies, and that's where rationality needs to step in and put on the breaks.

By flybefree on 3/15/2011 2:40:30 PM , Rating: 2
He's basically saying "I have no idea how this this works", but how about this wild guess, and so obviously, humans are causing the Earth to stop rotating. QED.

So researchers used computer climate models of Earth's oceans and atmosphere to generate changes made by humans.

This sounds like a large leap to me, as this is a part that is highly debatable. Reminds me of this:

They're fabricating out of thin air what they think is different in the last 80 years since 1930 based on data from only the past 150 years, arbitrary deciding what they consider "normal", then saying since the first 70 years are normal, the next 80 years must be human-caused abnormality. Sounds ridiculous to me.

"If you mod me down, I will become more insightful than you can possibly imagine." -- Slashdot

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