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Is there a better chart of temperature over the past billion years?

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bananas Donating Member (1000+ posts) Send PM | Profile | Ignore Thu Nov-10-05 01:12 AM
Original message
Is there a better chart of temperature over the past billion years?
Edited on Thu Nov-10-05 01:17 AM by bananas
I was trying to find a graph of temperature for the past billion years,
the only one I could find comes from an anti-global-warming website,
http://www.geocraft.com/WVFossils/Carboniferous_climate...

Is the data reasonably accurate - the temp has been a constant 22C,
occassionally suddenly switching to 12C? If there were error bars, what would they look like?

"Global Temperature and Atmospheric CO2 over Geologic Time"

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Odin2005 Donating Member (1000+ posts) Send PM | Profile | Ignore Sun Nov-13-05 02:47 PM
Response to Original message
1. The rough pattern is correct
But all the highs being so flat is not, and it is too simplified. the Earth flips back and forth between Hot-house mode (like the Age of Dinosaurs), where the pole are ice-free and the deep oceans are stagnant; and Ice-house mode (like today and the late Paleozoic, where there is ice at the poles and the big temperature gradient creates strong mixing of the deep oceans, making them oxygen rich) every few hundred million years.
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bananas Donating Member (1000+ posts) Send PM | Profile | Ignore Mon Nov-14-05 10:32 AM
Response to Reply #1
2. Any estimate when we go into hot-house mode again?
Welcome to DU :)
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Odin2005 Donating Member (1000+ posts) Send PM | Profile | Ignore Mon Nov-14-05 08:52 PM
Response to Reply #2
4. When Antarctica moves away from the soth pole.
thanks for the welcome. :)
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Bill McBlueState Donating Member (1000+ posts) Send PM | Profile | Ignore Mon Nov-14-05 01:23 PM
Response to Original message
3. look at the horizontal scale
That dip on the right side looks to be the last ice age. The scale is such that temperature changes over the past five hundred years -- which is what we're talking about when we discuss global warming -- are imperceptible.

If 100 million years is an inch, then 500 years is five millionths of an inch.
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bananas Donating Member (1000+ posts) Send PM | Profile | Ignore Tue Nov-15-05 03:14 PM
Response to Reply #3
5. yes - one pixel is about 1 million years
The gif is 660 pixels wide, so approx. 1M years per pixel.
We're 10,000 years into an interglacial period, 1/100 pixel wide.
I wasn't really discussing global warming,
I was curious about the flatness of the graph, a nearly constant 22C.
Apparently that isn't correct.
I found some related graphs here:
http://en.wikipedia.org/wiki/Paleoclimatology

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trotsky Donating Member (1000+ posts) Send PM | Profile | Ignore Tue Nov-15-05 05:19 PM
Response to Original message
6. Yeah, I would be pretty suspicious of those nice flat areas too.
I've come across that site before - the author clearly has a right-wing bias and is looking to put enough comments in to "debunk" the potential human causes global warming.

Problem is, it's not just CO2 responsible for global warming. There are lots of greenhouse gases; the earth's atmosphere has always been changing and just because CO2 was low (or high) says nothing about the concentration of other gases, or other factors that may or may not have been present.

Basically, the anti-environmentalists, after dragging their feet forever on whether global warming exists, are now acknowledging it, but claiming that it's a natural process and the tiny bit of activity by humans could not possibly be responsible in any way.

To do that, they always cherry-pick the numbers to support their conclusion.

Real climatologists look at all the numbers, and come to a conclusion after. The people who study this stuff the most seem to be the most concerned, so I'm inclined to trust them.

It's the same old science-haters vs. scientists battle that even rages here on DU.
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The Jacobin Donating Member (820 posts) Send PM | Profile | Ignore Tue Nov-15-05 09:18 PM
Response to Original message
7. That scale is crazy.
600 MILLION years ago?

I really only care about the last half-million or so ago. It is impossible to pick out the ice ages and the inter-glacial periods on that kind of graph.
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Ediacara Donating Member (1000+ posts) Send PM | Profile | Ignore Tue Nov-15-05 10:38 PM
Response to Original message
8. Not really accurate
This is average tropical temperature above and below today (the baseline):


And another temperature curve based on two different studies, with an expanded Quaternary:


And another very pretty one (recent on the left on this one):
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bananas Donating Member (1000+ posts) Send PM | Profile | Ignore Wed Nov-16-05 11:17 AM
Response to Reply #8
9. Thanks n/t
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