The hockeystick of 600 million years

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In summary, the conversation began with a discussion about a hockeystick graph as proof of global warming due to human activity. The purpose of the thread was to identify the truly important aspects of the topic, and the conversation turned to the topic of ice ages and their correlation with carbon dioxide levels. The participants discussed various theories and potential factors that could contribute to the onset of an ice age, such as changes in land mass and ocean currents. The conversation also touched on the idea of looking at the past 100,000 years for a more accurate correlation between ice ages and present topography. The conversation ended with a question about dating plant matter found under 3 kilometers of ice in Greenland and its relation to the depth of the ice.
  • #1
Andre
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In the other thread we were discussing the http://www.unc.edu/~sstaff/images/hockeystick.jpg as valid proof for global warming due to anthropogenic increase in greenhouse gasses. However the purpose of that thread was more philosophycal, intended to identify the truly important. And it was centered around Rich Muller priceless remark:

When a conclusion is attractive, I am tempted to lower my standards

But we strayed to ice ages when as intermezzo, I showed a (old) carbon dioxide graph going back 600 million years with seemlingly little correlation between ice ages and carbon dioxide level in the atmosphere.

So why don't we try and make our own 600 million years hockeystick, the relation between global temperatures and carbon dioxide.

For starters I found a more recent carbon dioxide graph from the same author:

http://calspace.ucsd.edu/virtualmuseum/climatechange2/07_1.shtml [Broken]

and the http://www.studyworld.com/newsite/ReportEssay/Science/Earth\The_Ice_Age-36240.htm or rather global temperatures. Here is something:

evidence of glaciation
has been found in at least five stretches of geologic time:
in the middle of the Huronian era in Precambrian time; at
the end of the Proterozoic Era; the middle of the Paleozoic
Era between the Ordovician and Silurian Periods; the late
Carboniferous and early Permian Periods in the late
Paleozoic Era; and in the Pleistocene Epoch

Also good ref:
Pre Mesozoic Ice Ages John, C Crowell 1999 GSA
ISBN 0-8137-1192-4

Note that the Ordovician – Silurian 440 Mya is about 18 times more CO2. The Devonian – Carboniferous border 350-360 million years (Mya) correspond with 3-4 times times the current carbon dioxide level while the Late Carboniferous - Early Permian era boundary, 290-286 Mya, is about level with nowadays. We also have the http://geog.hku.hk/undergrad/course/2038/2038cycl.htm [Broken] that shows the lack in correlation of CO2 especially in the 450 - 480 Mya time frame and a remarkable corrolation around the 300 Mya. On the other hand, between 200 - 100 Mya an inverted corrolation seems to exist with temps gradually rising and CO2 gradually lowering.

But how accurate is all of this? Can we make a more accurate approximation and see how the Carbon dioxide - greenhouse correlation really looks like.

There are however several more noise factors, the tectonics send the continents all around the globe. Formation of a big cluster of continents will affect global temperature, also when a sizeable continent passes the poles, a ice sheet will likely be formed, although one might wonder if that could happen with 18 times the current CO2 if the global warming idea was right. We also have no idea about the variability of the sun.
 
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  • #2
There are far to many variables and it is absolutely rediculous to go back 600 million years the structure content shape patterns winds were completely different. It is best to look at the past 100,000 years and check the correlation of ice ages with the present topography. This will yeild far more accurate results. There has been supposedly spikes in CO2 in all recent ice ages according to core samples. Since we are pesently off the charts this is a potentiality in the not so distant future.

On a side note of something which I have thought of was it may be that part of the reason an ice age occurs is the sudden loss of land mass due to rising waters. In the distant past the oceans were not as deep so the oceans would have been warmer regardless of the carbon dioxide content.

There is also the theory that the deeper waters in the atlantic which are heated by an undertow of warm water are impeded by the excess waters. These things may trigger different wind patterns etc... and all these things working in conjunction creates the ice age. The question is when did the first ice age happen and the second and so on.
 
  • #3
There are far to many variables

Well I agree about that and indicated already some problems but perhaps we could take those caveats into consideration.

It is best to look at the past 100,000 years and check the correlation of ice ages with the present topography.

More than happy to do that (have been peeking already) but we would restrict ourselves, missing the relevance of the long cycles. Some milankovitch but the most important one definitely not. 1,000,000 years would be better to have a full view on the 100,000 year cycle.

and all these things working in conjunction creates the ice age. The question is when did the first ice age happen and the second and so on.

First ice ages may be billion of years. If we limit ourselves to the middle to late Pleistocene ice ages there are several ideas about the onset. Particulary when we see that http://www.glaciology.gfy.ku.dk/ngrip/billeder_eng.htm [Broken] are found under 3 kilometres of ice in Greenland we seem have a lot of mysteries to solve.
 
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  • #4
Nice pictures. So did you carbon date the plant matter you brought up and at what depth was it in the ice. How much deeper is the ice from where the plant matter was extracted? Also is there a fairly linear time line for ice depth and time passage? What is the time per depth for this ice?

Note: I do think the shallow seas and different topography along with a warmer planet due to it's younger stage of development are why there was no ice age in the distant past. Plant coverage per surface area may also be a factor. Green plants capture the suns energy and transforms it into latent potential. Deserts flip flop like the wind due to low humidity/less plant density which helps towards humidity since plants capture water. The more of the planet we make into a concrete jungle the more potential of the temperate swings. This is presently not an effect because of the massive amounts of fossil fuel burned. What would happen if you cooled all the areas without the burn of fossil fuels or electrical energy? What is the total sum of fossil fuel output accoss the planet for a single year? What does that average per surface area is it negligable or is the presence of a city causing the shift of wind patterns which cause other things. To many varaibles all working in unison. Planets core, volcanic activity, meteors/comets strikes.
 

1. What is the significance of the hockeystick of 600 million years?

The hockeystick of 600 million years is a visual representation of the Earth's climate over the past 600 million years. It shows the fluctuations in global temperature and CO2 levels, and the correlation between them. This data helps us understand the Earth's climate patterns and how they have changed over time.

2. How was the hockeystick of 600 million years created?

The hockeystick of 600 million years was created using data from various sources, such as ice cores, sediment samples, and tree rings. These sources contain information about the Earth's climate in the past, and by analyzing and combining them, scientists were able to create a comprehensive timeline of global temperature and CO2 levels.

3. What does the hockeystick of 600 million years tell us about climate change?

The hockeystick of 600 million years shows a clear pattern of increasing global temperatures and CO2 levels over time. This indicates that the Earth's climate is changing rapidly, and humans are the main cause of this change through the emission of greenhouse gases. It also highlights the urgency of addressing climate change and implementing measures to reduce our carbon footprint.

4. Are there any limitations to the hockeystick of 600 million years?

Like any scientific study, the hockeystick of 600 million years has some limitations. The data used to create it may not be complete, and there may be uncertainties in the analysis. However, multiple studies have replicated the same pattern, giving us confidence in the overall accuracy of the hockeystick.

5. How can we use the hockeystick of 600 million years to inform future climate action?

The hockeystick of 600 million years serves as a valuable tool for understanding the Earth's climate and the impact of human activities on it. By studying the data and the patterns it reveals, we can make more informed decisions about how to mitigate the effects of climate change and protect our planet for future generations.

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