Friday August 7, 2009, 10:12 am
It doesn't matter what you eat...it's not you changing the climate! CO2 has nothing to do with it!

Long debate ended over cause, demise of ice ages – may also help predict future

CORVALLIS, Ore. – A team of researchers says it has largely put to rest a long debate on the underlying mechanism that has caused periodic ice ages on Earth for the past 2.5 million years – they are ultimately linked to slight shifts in solar radiation caused by predictable changes in Earth’s rotation and axis.

In a publication to be released Friday in the journal Science, researchers from Oregon State University and other institutions conclude that the known wobbles in Earth’s rotation caused global ice levels to reach their peak about 26,000 years ago, stabilize for 7,000 years and then begin melting 19,000 years ago, eventually bringing to an end the last ice age.

The melting was first caused by more solar radiation, not changes in carbon dioxide levels or ocean temperatures, as some scientists have suggested in recent years.

“Solar radiation was the trigger that started the ice melting, that’s now pretty certain,” said Peter Clark, a professor of geosciences at OSU. “There were also changes in atmospheric carbon dioxide levels and ocean circulation, but those happened later and amplified a process that had already begun.”

The findings are important, the scientists said, because they will give researchers a more precise understanding of how ice sheets melt in response to radiative forcing mechanisms. And even though the changes that occurred 19,000 years ago were due to increased solar radiation, that amount of heating can be translated into what is expected from current increases in greenhouse gas levels, and help scientists more accurately project how Earth’s existing ice sheets will react in the future.

“We now know with much more certainty how ancient ice sheets responded to solar radiation, and that will be very useful in better understanding what the future holds,” Clark said. “It’s good to get this pinned down.”

The researchers used an analysis of 6,000 dates and locations of ice sheets to define, with a high level of accuracy, when they started to melt. In doing this, they confirmed a theory that was first developed more than 50 years ago that pointed to small but definable changes in Earth’s rotation as the trigger for ice ages.

“We can calculate changes in the Earth’s axis and rotation that go back 50 million years,” Clark said. “These are caused primarily by the gravitational influences of the larger planets, such as Jupiter and Saturn, which pull and tug on the Earth in slightly different ways over periods of thousands of years.”

That, in turn, can change the Earth’s axis – the way it tilts towards the sun – about two degrees over long periods of time, which changes the way sunlight strikes the planet. And those small shifts in solar radiation were all it took to cause multiple ice ages during about the past 2.5 million years on Earth, which reach their extremes every 100,000 years or so.

Sometime around now, scientists say, the Earth should be changing from a long interglacial period that has lasted the past 10,000 years and shifting back towards conditions that will ultimately lead to another ice age – unless some other forces stop or slow it. But these are processes that literally move with glacial slowness, and due to greenhouse gas emissions the Earth has already warmed as much in about the past 200 years as it ordinarily might in several thousand years, Clark said.

“One of the biggest concerns right now is how the Greenland and Antarctic ice sheets will respond to global warming and contribute to sea level rise,” Clark said. “This study will help us better understand that process, and improve the validity of our models.”

The research was done in collaboration with scientists from the Geological Survey of Canada, University of Wisconsin, Stockholm University, Harvard University, the U.S. Geological Survey and University of Ulster. It was supported by the National Science Foundation and other agencies.

UPDATE: Science now has the paper online, which is behind a paywall. The abstract is open though and can be read below:
http://wattsupwiththat.com/2009/08/06/long-debate-ended-over-cause-demise-of-ice-ages-solar-and-earth-wobble/#more-9788

Friday August 7, 2009, 3:54 pm
Friday August 7, 2009, 3:49 pm
Sent. I believe lowering ones meat intake or stopping all together, making that concious personal decision ,will stop the use of anti-biotics and hormones by reducing the actual # of cows we have, besides improving your health. Your personal decision is very important and so are YOU, yes YOU. Your decision adds energy to the same decision made by others worldwide, and that how change is fueled. That simple really, just not easy because of disunity and other factors that were instilled in us in THE PAST. OUR Future lies in moving together, and sharing not only what we know but what we have. WE ARE all one. Dis-unity or seperation is an illusion, a third dimensional one that must start to serve us now instead of keeping us stuck in what WE ARE NOT, seperate. thx simone

Friday August 7, 2009, 8:14 pm
Thank you Simone. Noted with pleasure :-)

Friday August 7, 2009, 8:39 pm
Thankyou for your information noted .

Friday August 7, 2009, 9:33 pm
Buy Local.

Saturday August 8, 2009, 12:14 pm
Thanks Dear Simone.

Saturday August 8, 2009, 1:57 pm
How can you eat your little brothers and sisters???????????????????????we are all One in Oneness

Saturday August 8, 2009, 2:25 pm
it goes to show how greedy , cruel and uncaring poeple are. with all the information out about how raising animals for food hurts our enviroment and causes so many health problems. poeple still refuse to stop eating animal flesh. it is more important to feed thier selfish greedy pleasure than be compassionate to animals or save our planet.

no animal should have to face the slaughter house for greedy humans to eat them.

Saturday August 8, 2009, 2:27 pm
Simone, noted with thanks from a fellow vegan!

Saturday August 8, 2009, 4:24 pm
Wow, Global Warming is the sign post for the next ice age.
So the smog in California is ok, because it isn't changing the climate, no it is, this means that if we reduce our carbon emmissions less people would die of asthma and many other breathing problems.
We need to breathe clean air, to live healthy lives period. If we can reduce Carbon emmissions, and other forms of pollution from our air, then everyone will live healthier lives.
On meat production/comsumption, the fact is that there are a lot of people of the world are compassionate of all living things, and there are enough alternatives to get the protein that we need from plant products, that a human being has the intellect and free will to make a conscious choice to no longer consume animal products.
I am a vegan for environmental reasons, health reasons, and finally compassionate reasons, I have made this choice because of the reality that the Global Environment; is severely threatened by pollution, our world is greatly overpopulated, and we consume resources much faster than they can be replaced, those of course would be the ones that are renewable.
My aim in my everday live is to live lightly, consume less, help renew and restore natural resources, and to educate people, on how they to can live lightly.