Entire Antarctic Shelf splitting away from Continent.

[RiversideGator]

Midway:  Interesting points and analysis.  I see however that you still refuse to answer my question.  At least gatorback gamely attempted a response on your behalf. 

Now, I will address your post, point by point:

Actually, take a good look at your chart. Note that the Co2 levels fluctuate between 200 and 280 parts per million by volume roughly every 125,000 years or so. Also note that concurrent with the rise in co2 levels there is a rise in temperature of similar magnitude.

I am not denying that there appears to be an historical relationship between the temperature and CO2 levels in the atmosphere.  The questions are (1) which came first - the temperature rise or the CO2 rise and (2) what caused the rythmic CO2 and temperature spikes over the last 400,000 years?  You are allowed to admit that you have no clue and that any answer would be a WAG.  The point is if the CO2 rise came after the temperature rise, then we are probably looking at some variation in the Earth's orbit or some variation in the heat received from the sun and the CO2 rise was a consequence of this, not the cause.  Alternatively, if the CO2 rise came first and then caused the temperature rise then it is clear that some sort of natural force is causing the CO2 levels to rise and fall on a somewhat regular basis and that this appears to have some relationship with the temperature.  It must be largely natural because such CO2 spikes occurred well before the age of man.  Read the following for proof that the rise in CO2 levels often followed temperature spikes rather than preceded them:

There is a close correlation between Antarctic temperature and atmospheric concentrations of CO2 (Barnola et al. 1987). The extension of the Vostok CO2 record shows that the main trends of CO2 are similar for each glacial cycle. Major transitions from the lowest to the highest values are associated with glacial-interglacial transitions. During these transitions, the atmospheric concentrations of CO2 rises from 180 to 280-300 ppmv (Petit et al. 1999). The extension of the Vostok CO2 record shows the present-day levels of CO2 are unprecedented during the past 420 kyr. Pre-industrial Holocene levels (~280 ppmv) are found during all interglacials, with the highest values (~300 ppmv) found approximately 323 kyr BP. When the Vostok ice core data were compared with other ice core data (Delmas et al. 1980; Neftel et al. 1982) for the past 30,000 - 40,000 years, good agreement was found between the records: all show low CO2 values [~200 parts per million by volume (ppmv)] during the Last Glacial Maximum and increased atmospheric CO2 concentrations associated with the glacial-Holocene transition. According to Barnola et al. (1991) and Petit et al. (1999) these measurements indicate that, at the beginning of the deglaciations, the CO2 increase either was in phase or lagged by less than ~1000 years with respect to the Antarctic temperature, whereas it clearly lagged behind the temperature at the onset of the glaciations.

http://cdiac.ornl.gov/trends/co2/vostok.htm

Now, keep in mind that the present co2 levels are roughly 375 ppmv, significantly higher than anything on your chart. Since we have already established that there is a one to one correspondence between global temperature and Co2 levels based upon the data presented in your chart, and since our C02 levels are presently higher than anything on that chart, it would stand to reason that that relationship between C02 levels and Earth surface temperature is still operative. you should also note that the C02 and temperature variations shown on your chart are pretty much independent of insolation.

The CO2 levels appear to be slightly higher than at any point in the last 400,000 years.  But, this may not be relevant to the temperature if the CO2 levels are the result rather than the cause of the temperature rise.  Also, what caused the temperatures and CO2 levels to drop so many times in the past after having spikes?  Apparently, previous temperature rises have not been inexorable.  At some point, they have always reversed along with the CO2 levels.  BTW, the CO2 and temperature levels actually appear to track very closely the levels of insolation (that is solar intensity).  Also, CO2 levels in the atmosphere drop a good deal when the air sample is taken from above or near cool ocean waters - something which obviously is true for the Antarctic Vostok ice core samples - due to the ocean's role in absorbing atmospheric CO2.

I've given you these answers against my better judgment, because when you are confronted with material that disputes your political agenda, you proceed to deride those answers. please feel free to do so, as it just underscores the fact that you have no idea what you are looking at here.

Your answers are not sufficient and it is you who is blinded by ideology.

[RiversideGator]

So, what caused the CO2 spike on Earth 140,000 years ago?  Ancient SUVs?

No.  It was deep water hydrogen sulfide.  Basically, the theory goes like this.  Syberian Volcanos heated an area about the size of North America.  This caused deep water to warm up.  That in turned caused deep water hydrogen sulfide to produce this nasty green sulfur bacteria: organisms that required both light and free hydrogen sulfide (H2S).  That in turn caused the CO2 spike.  Everybody does know that warm water holds less CO2 right?   Google: Oceanic Anoxic Events.   

According to the much hated wikipedia, an anoxic event has not happened in millions of years though and the data from the ice cores goes back just 400,000 years:

Oceanic anoxic events occur when the Earth's oceans become completely depleted of oxygen (O2) below the surface levels. Although anoxic events have not happened for millions of years, the geological record shows that they happened many times in the past, and may have caused mass extinctions.

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

[gatorback]

So, what caused the CO2 spike on Earth 140,000 years ago?  Ancient SUVs?

No.  It was deep water hydrogen sulfide.  Basically, the theory goes like this.  Syberian Volcanos heated an area about the size of North America.  This caused deep water to warm up.  That in turned caused deep water hydrogen sulfide to produce this nasty green sulfur bacteria: organisms that required both light and free hydrogen sulfide (H2S).  That in turn caused the CO2 spike.  Everybody does know that warm water holds less CO2 right?   Google: Oceanic Anoxic Events.   

According to the much hated wikipedia, an anoxic event has not happened in millions of years though and the data from the ice cores goes back just 400,000 years:

Oceanic anoxic events occur when the Earth's oceans become completely depleted of oxygen (O2) below the surface levels. Although anoxic events have not happened for millions of years, the geological record shows that they happened many times in the past, and may have caused mass extinctions.

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

Scroll down a about half way: 

Here is another way of looking at oceanic anoxic events. Assume that the earth releases a huge volume of carbon dioxide during an interval of excessive volcanism; global temperatures rise due to the greenhouse effect; global weathering rates and fluvial nutrient flux increase; organic productivity in the oceans increases; organic-carbon burial in the oceans increases (OAE begins); carbon dioxide is drawn down (inverse greenhouse effect); global temperatures fall, and the oceanâ€"atmosphere system returns to equilibrium (OAE ends).

Maybe I didn't it it all right but, let's chart volcanism from -200,000 to today.  See if there's a spike when you mention.

[gatorback]

This is interesting. 



Right about the time we see a dramatic increase in CO2 emissions.  hmm.

[gatorback]

Oh, this one just proves it.   Massive volcanism 140,000 years ago increased water temp. Increased CO2.  No mass kill off  but increased CO2 levels.

[RiversideGator]

This is very interesting, gatorback.  It seems that volcanism's true role in CO2 emissions is not fully understood.

[RiversideGator]

Oh and CO2 levels have been much higher in the past:

Various proxies and modelling suggests large variations; 500 Myr ago CO2 levels were likely 10 times higher than now.[6] Indeed higher CO2 concentrations are thought to have prevailed throughout most of the Phanerozoic eon, with concentrations four to six times current concentrations during the Mesozoic era, and ten to fifteen times current concentrations during the early Palaeozoic era until the middle of the Devonian period, about 400 Mya

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

In the Cretacious Era, the era approximately 66+ million years ago, CO2 levels were 6 times what they were in the preindustrial era.
http://en.wikipedia.org/wiki/Cretaceous

And, the Earth has seen ice ages during periods when CO2 levels were 3 times the preindustrial level.
http://en.wikipedia.org/wiki/Permian

[gatorback]

so what's your point Riverstein? LOL

[RiversideGator]

Just that CO2 levels in the past have varied widely.    

[gatorback]

Right? lol.  Al Gore told us it's from greenhouse emissions and we're all domed unless we change our ways(even though he's not cut down usages).  So, now I'm confused.  If what we're being told isn't the complete story then somebody is dupping us for huge speaking engagement contracts?

[gatorback]

Will Al Gore Melt?
If not, why did he chicken out on an interview?
by FLEMMING ROSE AND BJORN LOMBORG
Sunday, January 21, 2007 12:01 a.m. EST

Al Gore is traveling around the world telling us how we must fundamentally change our civilization due to the threat of global warming. Last week he was in Denmark to disseminate this message. But if we are to embark on the costliest political project ever, maybe we should make sure it rests on solid ground. It should be based on the best facts, not just the convenient ones. This was the background for the biggest Danish newspaper, Jyllands-Posten, to set up an investigative interview with Mr. Gore. And for this, the paper thought it would be obvious to team up with Bjorn Lomborg, author of "The Skeptical Environmentalist," who has provided one of the clearest counterpoints to Mr. Gore's tune.

The interview had been scheduled for months. The day before the interview Mr. Gore's agent thought Gore-meets-Lomborg would be great. Yet an hour later, he came back to tell us that Bjorn Lomborg should be excluded from the interview because he's been very critical of Mr. Gore's message about global warming and has questioned Mr. Gore's evenhandedness. According to the agent, Mr. Gore only wanted to have questions about his book and documentary, and only asked by a reporter. These conditions were immediately accepted by Jyllands-Posten. Yet an hour later we received an email from the agent saying that the interview was now cancelled. What happened?

One can only speculate. But if we are to follow Mr. Gore's suggestions of radically changing our way of life, the costs are not trivial. If we slowly change our greenhouse gas emissions over the coming century, the U.N. actually estimates that we will live in a warmer but immensely richer world. However, the U.N. Climate Panel suggests that if we follow Al Gore's path down toward an environmentally obsessed society, it will have big consequences for the world, not least its poor. In the year 2100, Mr. Gore will have left the average person 30% poorer, and thus less able to handle many of the problems we will face, climate change or no climate change

[Lunican]

Oh and CO2 levels have been much higher in the past:

Various proxies and modelling suggests large variations; 500 Myr ago CO2 levels were likely 10 times higher than now.[6] Indeed higher CO2 concentrations are thought to have prevailed throughout most of the Phanerozoic eon, with concentrations four to six times current concentrations during the Mesozoic era, and ten to fifteen times current concentrations during the early Palaeozoic era until the middle of the Devonian period, about 400 Mya

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

In the Cretacious Era, the era approximately 66+ million years ago, CO2 levels were 6 times what they were in the preindustrial era.
http://en.wikipedia.org/wiki/Cretaceous

And, the Earth has seen ice ages during periods when CO2 levels were 3 times the preindustrial level.
http://en.wikipedia.org/wiki/Permian

How many humans were alive during this period of elevated CO2 levels? The discussion of global warming is about the earth supporting human life, not whether the earth will continue to exist.

[RiversideGator]

None that I know of.  But at what level is CO2 toxic to humanity?

[gatorback]

Oh and CO2 levels have been much higher in the past:

Various proxies and modelling suggests large variations; 500 Myr ago CO2 levels were likely 10 times higher than now.[6] Indeed higher CO2 concentrations are thought to have prevailed throughout most of the Phanerozoic eon, with concentrations four to six times current concentrations during the Mesozoic era, and ten to fifteen times current concentrations during the early Palaeozoic era until the middle of the Devonian period, about 400 Mya

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

In the Cretacious Era, the era approximately 66+ million years ago, CO2 levels were 6 times what they were in the preindustrial era.
http://en.wikipedia.org/wiki/Cretaceous

And, the Earth has seen ice ages during periods when CO2 levels were 3 times the preindustrial level.
http://en.wikipedia.org/wiki/Permian

How many humans were alive during this period of elevated CO2 levels? The discussion of global warming is about the earth supporting human life, not whether the earth will continue to exist.

L:  narrow it down....that  chart is about 1/2 billion years.  Just tell us what "period" you're asking about.

[Lunican]

None that I know of.  But at what level is CO2 toxic to humanity?

20,000 ppm is toxic to a human.

385 ppm is toxic to humanity.