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Re: Climate Science (Read 80951 times)
gizmo_2655
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Re: Climate Science
Reply #285 - Dec 17th, 2010 at 2:55pm
 
muso wrote on Dec 17th, 2010 at 2:13pm:
Gizmo, I'd like to continue our discussions on Climate Change if possible.

gizmo_2655 wrote on Dec 17th, 2010 at 1:48pm:
That's where the problem is Skippy....

There is no way to say that the current climate change isn't natural, except some 'simulations'....

There's nothing happening NOW that hasn't happened in the past, long before man developed industry or fire, (or worked out what causes babies for that matter)....other than some people saying it's 'faster' this time....which they can't prove, because there aren't any records of how fast or slow the increases were the last time....


OK, here's one. Ocean acidification (reduced alkalinity) is taking place as a direct result of increased CO2 concentration in the atmosphere. This will have increasing effects on a large number of marine organisms which rely on extracting calcium from the ocean for part of their structure.

Let's tackle this from the carbon dioxide perspective to start with.  

Do you dispute that the increase in CO2 in the atmosphere is a direct result of activities such as the burning of fossil fuel, the production of cement and the deforestation of tropical rainforest?

The carbon dioxide concentration in the atmosphere is very easily measured, and we can work out that it is increasing. It has increased to nearly 400ppm, up from about 320ppm in 1960.  

I'd just like you to answer honestly. I don't have a political agenda, and I'm not a 'froth at the mouth' greeny who thinks we should all become poor overnight, but in this case, I believe that there is a problem and we should acknowledge that fact so that we can work to remedy the situation before it gets worse.

I don't know if you're familiar with the Stockdale Paradox. You can read about General Stockdale here:

http://en.wikipedia.org/wiki/James_Stockdale

I'm a firm believer in facing the facts, "warts and all" so that we can be in a better position to tackle the problem.


And what was the Co2 level during the Late Carboniferous to Early Permian???

There have been lots of times in history when the Co2 level has been LOWER and the TEMPERATURE higher...

Check the 2nd graph at 300 million years..

http://www.geocraft.com/WVFossils/Carboniferous_climate.html

But of course you'll say that this site is funded by 'Big Oil'...because it goes against ACC doctrine....

Really, what are the chances that a bunch of 'naked apes' can work out the complexities of a 4.5 BILLION year old climate system, using LESS than 200 years of experience in weather science????
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« Last Edit: Dec 17th, 2010 at 3:01pm by gizmo_2655 »  

"I just get sick of people who place a label on someone else with their own definition.

It's similar to a strawman fallacy"
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muso
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Re: Climate Science
Reply #286 - Dec 17th, 2010 at 6:19pm
 
gizmo_2655 wrote on Dec 17th, 2010 at 2:55pm:
But of course you'll say that this site is funded by 'Big Oil'...because it goes against ACC doctrine....



That would be a simplistic answer. You know me better than that.  However, I'm pretty sure that that vegetation and other conditions during the Permian and Carboniferous were totally different to those of today. Since most of our coal comes from that period, I guess we were dealing with an densely forested world for at least part of that period. There was actually a period back then where the earth was  glaciated. There are various theories for this, including variables such as reduced solar output, increased volcanic activity etc, none of which apply today.

However, just to summarise the position you have chosen:

1. You are happy to quote the results of scientific research that  involves  an extrapolation of temperatures and atmospheric CO2 levels 280 million years ago despite the fact that the results of different studies differ by several magnitudes.

2. You are not confident that scientific methods can be used to  extrapolate CO2 levels and temperatures 50 years into the future, even though the results of various independent studies of the same emission scenario agree within 20%.

Take a moment to reflect. Can you see the problem here? Thanks for at least reading the content of my post. That's why I appreciate discussing this topic with you.
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« Last Edit: Dec 17th, 2010 at 6:28pm by muso »  

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Re: Climate Science
Reply #287 - Dec 17th, 2010 at 6:40pm
 
Hi muso.

What is you interpretation of the graph?
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Re: Climate Science
Reply #288 - Dec 17th, 2010 at 11:02pm
 
tallowood wrote on Dec 17th, 2010 at 6:40pm:
Hi muso.

What is you interpretation of the graph?


My guess (and it can only be a guess) is that the Siberian traps eruption sent enormous amounts of sulphate into the atmosphere at various points during this period. The eruption is coincident with the glaciation, for which there is extensive evidence.

Of course we can only speculate when it comes to 280 million years in the past. One thing is for sure - it represented a major extinction event. Whatever caused it was quite cataclysmic.

Quote:
Currently there is no single agreed upon event that caused the Permian mass extinction.  It is believed that a combination of factors caused the worst mass extinction the world ever experienced.  Environmental pressure on organisms caused by plate tectonics seems to have played an important role.  The combination of a single supercontinent affecting climate, glaciation and sea level with the additional environmental stress of the Siberian Traps may have been the driving force that nearly wiped out life on Earth.

http://park.org/Canada/Museum/extinction/permcause.html

The proxy temperature and CO2 data for 280 million years in the past are not particularly reliable.
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Re: Climate Science
Reply #289 - Dec 18th, 2010 at 7:06am
 
This paper suggests that climate sensitivity has been constrained by CO2 concentrations over the past 420 million years:

http://www.nature.com/nature/journal/v446/n7135/abs/nature05699.html

If you want a copy of the full paper, let me know.
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« Last Edit: Dec 18th, 2010 at 7:26am by muso »  

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Re: Climate Science
Reply #290 - Dec 18th, 2010 at 6:03pm
 
Thanks, muso, your interpretation is as good as any.
I have noticed 2 things about the graph.

1 From 266mya to 247mya level level of CO2 increased from 350ppm to about 1900ppm 86ppm/million years, increase rate of 0.082ppm/thy.
Compare to http://www.ozpolitic.com/yabbfiles/Attachments/vostok.jpg
Increase from 220mmp to 380ppm in 800 thousands, increase rate of 0.2ppm/thy

Fair bit of difference despite that ~250my ago there were more cataclysmic events then in last 1my. That is strange.

2 Increase of CO2 level is trailing increase of temperature, not other way around.

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Re: Climate Science
Reply #291 - Dec 18th, 2010 at 6:13pm
 
tallowood wrote on Dec 18th, 2010 at 6:03pm:
Thanks, muso, your interpretation is as good as any.
I have noticed 2 things about the graph.

1 From 266mya to 247mya level level of CO2 increased from 350ppm to about 1900ppm 86ppm/million years, increase rate of 0.082ppm/thy.
Compare to http://www.ozpolitic.com/yabbfiles/Attachments/vostok.jpg
Increase from 220mmp to 380ppm in 800 thousands, increase rate of 0.2ppm/thy


2 Increase of CO2 level is trailing increase of temperature, not other way around.



Horses for courses, Tallowood. As an ex rock breaker, you'll know that the distribution of landmass and by inference, the ocean currents were totally different during this period.  We don't really know for sure what the Earth's orbit was doing back then either. After all with Gondwanaland, the eccentricity must have been greater. It's an awful long time ago Smiley

There was also a lot more plant life during the Permian Carboniferous and it was probably much warmer than today.  Some studies say that it was of the order of 20 degrees warmer at times.

You also know of course that the actual temperatures you arrive at depend on the proxies used. It's extremely experimental trying to reconstruct paleoclimates that far back. All we have is fossil imprints.  

We also know that the output of the sun 500 million years ago was considerably lower than it is today.  

Now as far as the period covered by the Vostok cores is concerned,  the world was a lot more similar to its current state - except that there were not 7 billion people on Earth during most of that time.

What do you reckon?

Quote:
Fair bit of difference despite that ~250my ago there were more cataclysmic events then in last 1my. That is strange.


Well the Permo Triassic termination was a doozie whichever way you look at it. So you're saying that there were more cataclysmic events within a 30 million year period than in the last 1 million years?  I guess that stands to reason.
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Re: Climate Science
Reply #292 - Dec 18th, 2010 at 6:23pm
 
muso wrote on Dec 18th, 2010 at 6:13pm:
tallowood wrote on Dec 18th, 2010 at 6:03pm:
Thanks, muso, your interpretation is as good as any.
I have noticed 2 things about the graph.

1 From 266mya to 247mya level level of CO2 increased from 350ppm to about 1900ppm 86ppm/million years, increase rate of 0.082ppm/thy.
Compare to http://www.ozpolitic.com/yabbfiles/Attachments/vostok.jpg
Increase from 220mmp to 380ppm in 800 thousands, increase rate of 0.2ppm/thy


2 Increase of CO2 level is trailing increase of temperature, not other way around.



Horses for courses, Tallowood. As an ex rock breaker, you'll know that the distribution of landmass and by inference, the ocean currents were totally different during this period.  We don't really know for sure what the Earth's orbit was doing back then either. After all with Gondwanaland, the eccentricity must have been greater. It's an awful long time ago Smiley

There was also a lot more plant life during the Permian Carboniferous and it was probably much warmer than today.  Some studies say that it was of the order of 20 degrees warmer at times.

You also know of course that the actual temperatures you arrive at depend on the proxies used. It's extremely experimental trying to reconstruct paleoclimates that far back. All we have is fossil imprints.  

We also know that the output of the sun 500 million years ago was considerably lower than it is today.  

Now as far as the period covered by the Vostok cores is concerned,  the world was a lot more similar to its current state - except that there were not 7 billion people on Earth during most of that time.

What do you reckon?

Quote:
Fair bit of difference despite that ~250my ago there were more cataclysmic events then in last 1my. That is strange.


Well the Permo Triassic termination was a doozie whichever way you look at it. So you're saying that there were more cataclysmic events within a 30 million year period than in the last 1 million years?  I guess that stands to reason.


It is hard to read the past but it is even harder to read the future.

Where did all that CO2 come from 250 years ago?

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Re: Climate Science
Reply #293 - Dec 18th, 2010 at 8:10pm
 
tallowood wrote on Dec 18th, 2010 at 6:23pm:
It is hard to read the past but it is even harder to read the future.

Where did all that CO2 come from 250 years ago?



It's much easier to read 50 years ahead than it is to read 250 million years ago.

Re your question - I thought you were a geo.  The Earth's atmosphere was originally a CO2 nitrogen mix until the cyanobacteria came along and produced oxygen back in the Pre- Cambrian.

Over time the CO2 has gradually been sequestered into coal and oil, and carbonate rocks such as limestone and chalk.  

This is well known.  Why did you ask the question?
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Re: Climate Science
Reply #294 - Dec 18th, 2010 at 8:44pm
 
muso wrote on Dec 18th, 2010 at 8:10pm:
tallowood wrote on Dec 18th, 2010 at 6:23pm:
It is hard to read the past but it is even harder to read the future.

Where did all that CO2 come from 250 years ago?



It's much easier to read 50 years ahead than it is to read 250 million years ago.

Re your question - I thought you were a geo.  The Earth's atmosphere was originally a CO2 nitrogen mix until the cyanobacteria came along and produced oxygen back in the Pre- Cambrian.

Over time the CO2 has gradually been sequestered into coal and oil, and carbonate rocks such as limestone and chalk.  

This is well known.  Why did you ask the question?



Thanks for correction, it meant to be 250 millions.

I asked because before the rise in the period CO2 level was only 350ppm so 1550ppm had to come from somewhere. Decline in vegetation alone does not explain it and the rise itself is an anomaly or as you called it cataclysmic.


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Re: Climate Science
Reply #295 - Dec 18th, 2010 at 9:17pm
 
muso wrote on Dec 18th, 2010 at 8:10pm:
It's much easier to read 50 years ahead than it is to read 250 million years ago.





Sure it is. If you are a boffin, anything's possible.




These guys were looking only 24 years ahead, from 1975 to 1999 and they got everything exactly right. How much easier it would be to predict 50 years ahead! Or a hundred! Every schoolbot knows that the world today is exactly as Jules Verne predicted.

More gin all 'round!!!!

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Re: Climate Science
Reply #296 - Dec 18th, 2010 at 9:27pm
 
The singularity is near, friends. If Moore's Law continues unabated and is able to assume another computational substrate then superintelligent robots will dominate the future. Man will not be able to keep up unless he merges with his own technology.
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Re: Climate Science
Reply #297 - Dec 18th, 2010 at 9:55pm
 
Soren wrote on Dec 18th, 2010 at 9:17pm:
muso wrote on Dec 18th, 2010 at 8:10pm:
It's much easier to read 50 years ahead than it is to read 250 million years ago.





Sure it is. If you are a boffin, anything's possible.






We're not talking about predicting anything other than mean global temperatures. Not fashion, not music trends, not trends in psychology, not new technology - just average global temperatures.

To refresh your memory, this shows just how much they change over time (and please examine the two charts and note the subtle differences)

Most climatic data is averaged over at least a 20 year period. If we take the temperature maps for Australia, you'll find very little difference over the last 50-100 years. For example:

...

and

...


Now does it look like such an incredibly difficult task?
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Re: Climate Science
Reply #298 - Dec 18th, 2010 at 10:03pm
 
Cannot see future. Only past. Future lies beyond. Need time machine to see future.
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Re: Climate Science
Reply #299 - Dec 18th, 2010 at 10:18pm
 
JC Denton wrote on Dec 18th, 2010 at 10:03pm:
Cannot see future. Only past. Future lies beyond. Need time machine to see future.


OK. Well Hansen et al in 1988 provided a prediction of future temperatures. That's not 50 years ago, only 22, but it would be interesting to see how close he got to predicting actual climate, would it not?

He revisited that original 1988 paper a few years ago.

Here is the abstract:

Quote:
Global surface temperature has increased Ϸ0.2°C per decade in the past 30 years, similar to the warming rate predicted in the 1980s in initial global climate model simulations with transient greenhouse gas changes. Warming is larger in the Western Equatorial Pacific than in the Eastern Equatorial Pacific over the past century, and we suggest that the increased West–East temperature gradient may have increased the likelihood of strong El Niños, such as those of 1983 and 1998. Comparison of measured sea surface temperatures in the Western Pacific with paleoclimate data suggests that this critical ocean region, and probably the planet as a whole, is approximately as warm now as at the Holocene maximum and within Ϸ1°C of the maximum temperature of the past million years.

We conclude that global warming of more than 1°C, relative to 2000, will constitute ‘‘dangerous’’ climate change as judged from likely effects on sea level and extermination of species.


and here is the original paper:
http://pubs.giss.nasa.gov/abstracts/1988/Hansen_etal.html

Remember that climate modelling at that time was not as sophisticated as it is now, but I think you'll agree that it was pretty close.

The graph shows predicted against actual forcing. Scenario B most closely reflected actual emissions.

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