Thursday, August 16, 2007

What Causes Ice Ages?

Since we have a consensus on climate science could some one please tell me the cause of ice ages?

18 comments:

Pal2Pal said...

My scientific explanation:

that ocean conveyor belt thingy gets all screwed up

M. Simon said...

Do the climate models show that?

What causes the screw up?

Pal2Pal said...

I saw it on a Discovery channel special, but here is a link that explains it.

A Chilling Possibility

M. Simon said...

Let me quote from "Chilling..."

For example, as the world warmed at the end of the last ice age about 13,000 years ago, melting ice sheets appear to have triggered a sudden halt in the Conveyor, throwing the world back into a 1,300 year period of ice-age-like conditions called the "Younger Dryas."

Will it happen again? Researchers are scrambling to find out.


In other words as of 2004 the climate models have no clue.

An Ice Age/Warm Age transition is the biggest event in climate science. We should understand how it works if the science is settled.

Pal2Pal said...

I'm more worried about Yellowstone Super Volcano erupting than I am about global warming or cooling. It is overdue.

As to the Conveyor Belt, I don't think they've even known about or grasped the significance of it until just a few years ago. If they even have all the measuring instruments in place, I doubt they've gathered enough current data to be make any definitive conclusions.

I remember on the TV special I watched, various scenarios were discussed such as most of the rivers in Europe and Russia freezing which would be a disaster for commerce that depends on those waterways.

Snake Oil Baron said...

Ice ages were caused by Karl Rove to discredit Global warming. He is an evil time traveler. Al Gore needs to go back in time and defeat him.

Anonymous said...

"What causes ice ages?"

Well, you see, it is er, ahem, ah, not easily explained. But it is thoroughly understood by those who need to know.

And an ice age couldn't happen again. AGW is what happens from here on. The science is settled.

Dan said...

If the ocean conveyor breaks down where does the heat go? Does variation in the suns output explain all of it, or does the tropics become an uninhabited torrid zone as Aristotle theorized during the Iron Age cold epoch?

Does global warming and ice ages go hand in hand as localized events?

Can’t help wondering.

Snake Oil Baron said...

When will the Sahara heat pump kick in again and turn North Africa into marshlands and savannah? That's what I want to know, dawl gumit!

I have heard some speculation that our solar system goes through dusty regions periodically as it goes around the galaxy and some of the dust gets through the solar winds and blocks some of the sunlight reaching earth, causing a cooling with the reflective ice feedback and the "Hey Hey - THERE'S FROSTBITE!" Glavin.

Doug said...

Pat Rogers said...
According to the newly released New York City Police Department report, "Radicalization in the West: The Homegrown Threat" by Mitchell D. Silber and Arvin Bhatt Senior Intelligence Analysts NYPD Intelligence Division, prisons are "A Radicalizing Cauldron".

"Prisons can play a critical role in both triggering and reinforcing the radicalization process. The prison’s isolated environment, ability to create a “captive audience” atmosphere, its absence of day-to-day distractions, and its large population of disaffected young men, makes it an excellent breeding ground for radicalization."

So one wonders why America pursues a drug war policy that gives our nation a world record prison population.

U.S. drug war prisons: "A Radicalizing Cauldron"
http://independentsofamerica.blogspot.com/2007/08/us-drug-war-prisons-radicalizing.html

Doug said...

Pat Rogers

Doug said...
This comment has been removed by the author.
papertiger said...

Well Rush Limbaugh (the national anchor, doctor of democracy, big lovable fuzzball, doing the job that the drive by media refuses to do) mentioned this very topic today in passing.
From that little blurb I tracked down Data on Atlantic flow is undercut.
Don't let the title fool ya. It's not about the need for North Atlantic tampons.
It seems that whatever climate/fluid dynamic models the IPCC, GISS, NCDC, and the greater AGW hysterical community at large have been using, they are all wet.
Up until Torsten O. Kanzow, an oceanographer at the National Oceanography Centre in Southampton, England, and William E. Johns, an oceanographer at the University of Miami, made a detailed study, the amount of water flowing through the Gulf Stream was based on a handful of measurements made by boats in the eighty's and nineties.
These guys finally got the bright idea to set bouys to get real time data. And they found out that the Atlantic conveyor, which had a starring role as the boogieman in ALGORE's movie, isn't slowwing down whatsoever.
If you can find someone willing to bet on the UK being thrown into an iceage due to Gulf Stream desalination (I would try here. These people seem pretty gullible), I would bet the farm, and the combine.

linearthinker said...

These guys finally got the bright idea to set bouys to get real time data. And they found out that the Atlantic conveyor, which had a starring role as the boogieman in ALGORE's movie, isn't slowing down whatsoever.

Linear thinking at it's best. Some more:

Reacting yesterday to word that certain European governments and officials are suddenly trying to abandon their costly "global warming" policies, Royal Astronomical Society fellow Benny Peiser, of the science faculty at Liverpool John Moores University in Great Britain, recalls the teachings of Marcus Aurelius: "The object of life is not to be on the side of the majority, but to escape finding oneself in the ranks of the insane."

linearthinker said...

Here's some more followup on papertiger's comment above:

The publications in Science show that the remarkable instrument array is working effectively and is bringing in some surprising results. The full range of variability measured in the Atlantic MOC is large. It can range from as little as 4 Sverdrups to as much as 35 Sverdrups. (A Sverdrup is a measure of ocean flow, with one Sverdrup equivalent to one million tonnes of water a second.) The year–long average of the MOC calculates at around 19 Sverdrups, in agreement with earlier estimates.

Prof. Marotzke explains, “There is no indication of an MOC slowdown. And the large fluctuations explain why previously it was diagnosed that a slowdown had already happened. By chance, measurements were taken at a time when the MOC happened to be quite weak.”

With the instrument array it is feasible to monitor the annual average MOC to a resolution of about 1.5 Sverdrups, or about 8 percent of the mean value. This would be sufficient to detect any large, abrupt changes in the circulation, critical to planning for future climate change.


That guy Sverdrup must have a great fan club. Imagine having one million tonnes of seawater per second named after you.

And, why wasn't the current monitored further? Well, the issue was settled. The evidence was conclusive, and supported the consensus. Move along there. We scientists have important policy work to attend to.

Just a side note. I'd have probably used rubber duckies, but then I couldn't have gotten my project published.

[Thank you, tiger.]

greg_k said...

I'd guess it's a bunch of stuff, including solar variance, really big volcanoes and asteroid impacts, and a whole host of things we don't yet know about: cosmic rays, anyone?

papertiger said...

Your welcome Lin
and thank you for digging out the Science. It's always risky taking an LATimes story literally.

papertiger said...

Looking at A Chilling Possiblity.
Have you noticed the ice is following the Geomagnetic pole?