Posted on 04/06/2010 10:49:31 AM PDT by decimon
(Santa Barbara, Calif.) –– In an analysis of the past 1.2 million years, UC Santa Barbara geologist Lorraine Lisiecki discovered a pattern that connects the regular changes of the Earth's orbital cycle to changes in the Earth's climate. The finding is reported in this week's issue of the scientific journal Nature Geoscience.
Lisiecki performed her analysis of climate by examining ocean sediment cores. These cores come from 57 locations around the world. By analyzing sediments, scientists are able to chart the Earth's climate for millions of years in the past. Lisiecki's contribution is the linking of the climate record to the history of the Earth's orbit.
It is known that the Earth's orbit around the sun changes shape every 100,000 years. The orbit becomes either more round or more elliptical at these intervals. The shape of the orbit is known as its "eccentricity." A related aspect is the 41,000-year cycle in the tilt of the Earth's axis.
Glaciation of the Earth also occurs every 100,000 years. Lisiecki found that the timing of changes in climate and eccentricity coincided. "The clear correlation between the timing of the change in orbit and the change in the Earth's climate is strong evidence of a link between the two," said Lisiecki. "It is unlikely that these events would not be related to one another."
Besides finding a link between change in the shape of the orbit and the onset of glaciation, Lisiecki found a surprising correlation. She discovered that the largest glacial cycles occurred during the weakest changes in the eccentricity of Earth's orbit –– and vice versa. She found that the stronger changes in the Earth's orbit correlated to weaker changes in climate. "This may mean that the Earth's climate has internal instability in addition to sensitivity to changes in the orbit," said Lisiecki.
She concludes that the pattern of climate change over the past million years likely involves complicated interactions between different parts of the climate system, as well as three different orbital systems. The first two orbital systems are the orbit's eccentricity, and tilt. The third is "precession," or a change in the orientation of the rotation axis.
Weak eccentrics ping.
A rediscovery of the Milankovich Cycles.
Cyclic climate change?
No way!
</sarcasm off>
It’s ridiculous to think that little things like the orbits of celestial bodies would effect climate, when it’s obvious that climate is driven exclusively by backyard barbecues.
Move along, nothing to see here. The science is settled.
Let’s see, 1.2 million years versus 200 years of analytical data. Clearly, the 200 years of data is a far better indicator of trends!
In a related subject, Albert Pujols, who hit two home runs yesterday, is on a pace to hit a record shattering 324 home runs in 2010. Alex Rodriguez, on the other hand, is on pace to hit 0 for 2010.
She proabably thinks the earth is round, too. Heretic!!! /s
I think that we may be on to something here. Too early to tell for sure, but it just may be that the Sun has a bigger effect on our climate than do humans. More research needed.
That shouldn't be surprising at all. A large change in eccentricity means that the Earth is closer to the sun for half the year. A weak change means that, on average, the Earth will be farther away from the sun than in cycles with a "strong" change.
Great tie-in of science and opening day!
Yeah, I thought this had been brought up before except she seems to be saying that a more eccentric orbit produces a minimal change in climate. and vice versa.
So it really does not have anything to do with my wife's SUV?
1.2 million is NOTHING to a 4.6 billion year old planet.
As time goes by, we may find that the solar magnetic field, in its interactions with the Earth’s magnetic field, may affect things beyond just weather. I would not be surprised to find interactions affecting earthquakes and volcanism.
But , but, but, algorejr an Mortimer Snerd have this other theory.
Thanks I could not remember his name. I read a small book regarding his theory about 20 years ago. I loaned it out and never got it back.
By the way: did she even mention Milankovich’s theory?
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.
