New Ice Age Theory 272
amigoro writes "Most believe that the ice ages are the result of subtle changes in Earth's orbit, known as the Milankovitch cycles. According to one scientist, that is not the case. Robert Ehrlich of George Mason University in Fairfax, Virginia, has developed a model which hypothesizes a dimmer switch inside the sun that causes its brightness to rise and fall on timescales of around 100,000 or 41,000 years, exactly the same period as between ice ages on Earth. The main problem with Milankovitch cycles is that they can't explain how the ice ages go from 100,000 year cycle to 41,000 year cycle. The cycles predicted by Ehlrich's model line up with the observations."
Broken link to details. (Score:3, Informative)
Who the hell knows...
From TFA: "In an article appearing in the journal Nature, Ehrlich describes..."
Click the nature link and you end up at NewScientist.
Even if this guy has a viable mechanisim for his "dimmer switch", I can't see that it has any implications for our current climate problems. Wake me up again iff someone finds an abstract.
Re:To the Retard who Posted this Story (Score:5, Informative)
That's less "difference in atmospheric composition" and more "has an atmosphere or not."
This is an inference -- not a prediction (Score:5, Informative)
Shouldn't this be? The cycles predicted by Ehlrich's model were inferred from observations. Implying that a prediction is lining up with observations is not the same as a prediction that's inferred from observations. And besides, the article is claiming it's an inference based on past observations, not a prediction which has been verified with observations.
The article itself makes no such wild encompassing claim.
Re:Combination (Score:5, Informative)
Re:Ice Age Frequency (Score:3, Informative)
Re:This is an inference -- not a prediction (Score:3, Informative)
Re:To the Retard who Posted this Story (Score:2, Informative)
I think global warming is accepted by those with open minds, but keeping an open mind means looking at other science as well. It's how we got here.
Re:To the Retard who Posted this Story (Score:3, Informative)
Venus' albedo is 0.65; i.e. it reflects 65% of the light, thus it absorbs 35%. Earth's albedo is about 0.3, the Moon's 0.12. Venus would be even hotter if it was less reflective, but still it absorbs a lot of sunlight.
Re:Ice Age Frequency (Score:3, Informative)
Lots of nice graphs at the end of it.
All based on 18O/16O ratios
It's all here on the archive in glorious pdf-ed Latex.
http://arxiv.org/PS_cache/astro-ph/pdf/0701/07011
Re:Real source (Score:5, Informative)
We actually did a simulation using a coupled GCM to remove the Tibetan pleateau all together, to see its influence. The result was that some aspects of the current climate system, for example the Asian monsoon, or the western Pacific warm pool has weakened dramatically. The jet stream did change dramatically, but that alone was not enough to trigger a continental ice sheet.
We then changed the orbital parameters to see which impact is greater. The result was that a slight change in orbital parameters is far efficient in changing the northern hemispheric surface temperature in the order of 7-8 degC.
So the parent is correct in some respect. I guess he just didn't bother to explain in detail.
Re:Ice Age Frequency (Score:2, Informative)
Get the paper here (Score:3, Informative)