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Can we expect an ice age to start every 36,500,000 days or so?

While the battle for what's right and wrong roars on concerning climate change as a whole, it seems that many small observations are left to collect dust while politicians and activists concentrate on their own immediate problems. It can seem overwhelming at times when science-fact is pushed into a corner because it doesn't help support a growingly concerned (or unconcerned) community. Nevertheless, these data and observations are important in the long term to help climate scientists and geologists understand how the Earth changes over millennia and how those changes are affecting the current climate.

Some great finds have made their way into 
DailyTech's news reel already this year. In January, the National Center for Atmospheric Research and the University Corporation for Atmospheric Research published findings that suggested tiny geological formations could be responsible for regulating the entire North American region. In February, researchers at the Woods Hole Oceanographic Institute released data that suggested Greenland's rapid glacial retreat is being at least marginally affected by warm subtropical waters making their way along currents all the way into the country's fjords. These findings suggest that at least one part of the northern hemisphere's climate is controlled more than partially by ocean systems.

This week, University of California, Santa Barbara geologist Lorraine Lisiecki has presented information linking long-term climate cycles more closely with Earth's ~100,000 year orbital cycle. And not only does the information suggest quite clearly that ice ages are an effect of these cycles, it shows that how adversely the orbit changes inversely affects the climate change. The idea that the planet's orbit is a large or ultimate factor in the rise and fall of ice ages is not new, however, the study shows a very strong connection between hard data and theory.

"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. It is unlikely that these events would not be related to one another," explains Lisiecki.

The data correlates the climate change to two different aspects of the Earth's orbit around the sun as well as its own rotational oscillations. The first is the Earth's orbital eccentricity, or how elliptical/circular the orbit is. The second is its inclination, or the angle of its path compared to the solar orbital mean. The planet's rotational precession, or how the planet wobbles around its own rotational axis, is the third contributing factor in Lisiecki's study.

While this evidence strongly suggest patterns of climate due to local astronomy, Lisiecky does not solely attribute the cyclical changes to her findings. She stresses that these kinds of total climate changes are most likely a complicated interplay between the astronomical system and the Earth's own weather and more immediate systems. Further, the inverse relationship between the strength of climate change and the change in orbital pattern suggest that the overall system simply isn't that easy to decipher.

Lisiecki used climate data for the last 1.2 million years collected from 57 separate ocean sediment cores in her study. With this data she discovered the correlation between orbit and climate. Her full findings have been published in this week's edition of 
Nature Geoscience.



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RE: Yet another reason for global warming
By 3minence on 4/7/2010 8:56:26 AM , Rating: 4
I'm beginning to think their are no moderates left in the world. So many people say it must be one way or another with no mixing in the middle.

Global warming and cooling has been going on for millions of years. The earth has not suddenly stopped its natural cycle of change and allowed anthropogenic greenhouse gasses to take over it's job. However, that does not mean humans are not effecting the climate. We may be accelerating the process or increasing the peak temperatures experienced.

When ever a natural cause of global warming is identified or talked about, so many point to it and dismiss the possibility of man made global warming. Can't man made factors also be influencing the climate as well as natural ones? Does it really have to be one or the other?


By porkpie on 4/7/2010 9:13:21 AM , Rating: 5
"Can't man made factors also be influencing the climate?"

You don't understand the debate. The values for climate sensitivity (the amount the earth warms from a given amount cf CO2) were calculated by assuming the majority of all warming we've seen since 1850 was due to CO2. In other words, the assumption was that natural forces were minor...and thus CO2 had to be being "amplified" by positive feedback in our climate system.

When you use that artificially high figure to calculate what temperature the earth will be in 100 years, you get scary results. However, as research is showing more and more, those early researchers were wrong to discount the natural factors affecting climate. While CO2 does exert some influence, it is a very small one, and moderated by increasing warmth and water vapor, not amplified by it.

Without that positive feedback assumption, the estimated temperature increase between now and the year 2100 from increased CO2 is nearly too small to measure. Thus, not a problem.


By JediJeb on 4/7/2010 10:02:26 AM , Rating: 2
quote:
Does it really have to be one or the other?


It really is both, but how much of each is what is blown out of proportion. There are just too many variables to plug into models to get it all right. Noone really knows if mans effect is warming the earth too much or maybe just maybe helping to stave off the next mini Ice Age. What would people do if they found out that by reducing our influence on the climate we accelerate the coming of the next Ice Age instead of slowing some drastic over heating?

Right now being a alarmist about man's contribution to warming is like looking up into the sky at night and seeing a meteor and proclaiming a star just fell to earth because the only data you have about stars is you see points of light in the sky. There may be tons of data out there for climate scientist to sift through, but really it is still just a drop in the bucket compared to all of the data needed to account for every single influencing factor on our climate. This report shows a link to orbital cycles, another shows a link to solar cycles, others do show links to CO2, or water vapor, or dust, or ocean currents. Then you have to factor in reflectivity of the earth's surface which changes by season due to amount of snow cover and foliage. Heck whether or not the trees have leaves on them at a certain time of year can effect overall temperatures. Nobody knows ever little or large factor that needs to be put into the equations to build the correct model, that is why most of the models are not very accurate beyond a few years.


By rdhood on 4/7/2010 10:50:45 AM , Rating: 5
quote:
Does it really have to be one or the other?


It does if there are political factions in the world that insist on taking my wealth from me in the name of "global warming". When the U.N. wants to establish payment from first world countries (i.e. United States) to developing countries (i.e. China and India and Brazil + 100 others) in the name of "global warming", then it HAS to be one or the other. When the Democrats want to enact Cap-and-trade to generate revenues that will increase my cost of energy by 1/3, AND increase my taxes to subsidize "the poor" in order to allow them to pay THEIR increased energy costs, then it has to be one way or the other.


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