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Geology, Palaeontology & Archaeology / Are current pre-industrial CO2 levels lowest in Earth's history?
« on: 21/07/2010 13:41:14 »
Only the Carboniferous Period had CO2 levels as low as present.
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Your saying it could be green obsidian? i found it in the Russian river not near crater lake.
Can I point out that Kilburn might be a really good name for someone drilling holes in volcanoes.
Continental Drift was not a settled theory when I was in undergraduate school and majoring in Geology.
As temperature rises, the atmosphere is able to hold more water as vapor. Could this act as a buffer system to absorb some of the impact?
As I understand it, the ice caps have melted many times in the earth's history (non present during most of the mesazoic era).
If they completely melted, how much devestation could we expect to see?
The fact that peer reviewed literature may use the term interchangeably is just down to sloppy thinking/wording.
Although we may have only known about Plate Tectonics for fifty years it does not depend upon proxy data because the historical data is still there to be sampled, at the bottom of the oceans and in the rock formations on land. While this data may not be able to give us precise rates of movement, they confirm tectonic action, so while the establishment of the process of Plate Tectonics does not depend upon proxy data, the rates of movement will do, because we weren't there to actually measure them. The process of Plate Tectonics and the rates of movement are once again, two different things.
However, if you really want to look at it your way then all data is proxy. For example, does a thermometer really tell us the temperature of something, or does it just provide proxy data, because all it can really tell us directly is how it is reacting, and not the direct temperature of the thing we are trying to measure?
My common sence informs me that as Ocean and Atmospheric temperatures rise, partly due to human generation of green house gases, then this will increace water evaporation and hold more vapour in the atmosphere thus increasing cloud formation and providing more greenhouse effects on a compounding basis.
Actually frethack, you said that they were not entirely different, suggesting that they were, to some degree, the same.
QuoteThe sun's magnetic field - the heliosphere - is our first line of defense...
Oops! The two are entirely different things. However, it then goes on to say...QuoteRight now, the sun's magnetic field is weak...
When I think they may have meant that the heliosphere is (relatively) weak.
You're also guilty of exaggeration in suggesting that I was disregarding research based upon proxy data when it was pretty clear that I was questioning the accuracy, and therefore the value, of forecasts based upon that proxy data...
Your comments re plate tectonics, evolution and the notion of the atom are not just plain silly but wrong too, for we do not depend upon extrapolated proxy data for them, but correlations of hard data.
The solar magnetic field and the heliosphere are entirely different things, even though they might be linked, just as I am entirely different from the building to which I am clearly linked by living in it. Trying to claim otherwise, to prove a point, is disingenious.
While we may have been observing solar activity for more than fifty years and for more than five cycles we only have direct measurements of solar magnetic activity for those fifty years and those five cycles, and just as five cycles isn't really enough to establish trends and maxima/minima, it is also insufficient to provide a mapping basis for the accurate extrapolation of historical observations where it was not possible to record that data directly. While the tree ring and ice core data is valuable, inferring conditions with a high degree of accuracy over such long periods of time from such a small overlap is unwise, especially when it is remembered that the conditions during the period when the hard data was collected is known to be different to the period being extrapolated, because...
...these particles have mass and are accelerated to nearly the speed of light, seems to me that is a lot of energy entering the system, and our main line of defense(our magnetic field) seems to be having issues at the moment.
I don't think that the current level, being '19% higher' (a percentage of what? - it appears to be a percentage of the total range) than the previous highest level really amounts to very much, being based upon just five previous cycles. It would be rather surprising if, after only five previous cycles we had established clear maxima and minima.
That article also seems to confuse the magnetic field and the heliosphere...QuoteThe sun's magnetic field - the heliosphere - is our first line of defense...
Oops! The two are entirely different things. However, it then goes on to say...
QuoteRight now, the sun's magnetic field is weak...
When I think they may have meant that the heliosphere is (relatively) weak.
There's then a bit of sensationalist speculation...QuoteWe could see cosmic ray fluxes jump all the way to 30 percent above previous Space Age highs
...but then of course, we might not.
Finally though, it does add a bit of perspective...QuoteIndeed, we've weathered storms much worse than this. Hundreds of years ago, polar ice cores show, cosmic ray fluxes were at least 200 percent higher than they are now.
...and then admits...Quote"The space era has so far experienced a time of relatively low cosmic ray activity," says Mewaldt. "We may now be returning to levels typical of past centuries."
...which really just highlights the fact that five cycles, and fifty years, isn't enough to establish any sort of meaningful trend.
Apparently, generally speaking, the odds are not good ...
Haematite seems to be the most common "Meteorwrong" but would be revealed by streak test.