Guest Post by Bill Illis
This post is the first of what will likely be a series on the PaleoClimate.
In this part, we are just going to go through the various estimates for Temperature, CO2 and Sea Levels in the PaleoClimate. This post is also about making the data available to everyone so that others can use it. All of the data presented in this post is available for download at the end in easy to use Excel spreadsheets which also incorporates direct links to the actual data sources used.
PaleoClimate Temperature Estimates Over the Past 570 Million Years
There are various sources we can use for estimates of Temperatures in the PaleoClimate.
We have the ice core dO18 isotope data going back 800,000 years. James Zachos has a high resolution database of dO18 isotopes going back 67.0 million years. Jan Veizer has accumulated an isotope database that goes back 526.5 million years. Dana Royer and Robert Berner applied a ph-correction factor to Veizer’s database and Christopher Scotese has developed Temperature estimates that extend back into the pre-Cambrian.
For the most part, the Temperature estimates are based on dO18 isotopes and these have proven to be reasonably reliable, or more accurately, to be the most reliable temperature estimation method that is available.
The isotope data does require a number of different transformations and smoothing to make it useful as a Temperature proxy. Nobody is really sure what the proper way to carry this out is.
For one, it must be detrended as the data becomes older. The dO18 declines over time due to the radioactivity of the Earth. The above estimates are based on a simple linear detrending formula. The rationale is that the radioactive conditions would have remained reasonably constant over the last 530 million years. Others have used a second order polynomial but this does not result in much difference.
It has been noted that the dO18 isotope data should also be corrected for ice volume, sea level, the concentrations of CaCO3 in the oceans and -ph conditions of the oceans. Royer and Berner applied a ph-correction factor based on Berner’s GeoCarb III CO2 estimates. Again, this doesn’t make much difference except that Royer and Berner’s numbers are now lower than Veizer’s original database would point to.
Effectively, any transformation carried out has still got to match the record that we know about. It is still going to have to show a Carboniferous ice age, an Ordovician ice age, a hot Permian Pangea climate, a hot Cretaceous period, an Antarctic glaciation and the recent ice ages.
In other words, no matter what corrections are applied, one should just end up with something very similar to the above chart.
Detailed Temperature Estimates Over the Past 530 Million Years
Veizer’s database contains over 16,600 individual dO18 isotope data points extending back 526.5 million years. There is sufficient resolution throughout the database that we can be reasonably certain about any specific period.
The above chart has been constructed using Veizer’s data with two different smoothing parameters; a shorter one which preserves more detail and then one that emulates the Phanerozoic Climate Change chart by Robert Rohdes of Global Warming Art. It is likely that both are reasonably accurate and sometimes less smoothing is preferred to more smoothing so that more information can be extracted.
In this case, there really is more information available from the shorter Gaussian smooth. Immediately evident is that certain large temperature changes coincide with some of the large Mass Extinction events in the planet’s history.
The really unusual one is the Permian Extinction event in which 96% of marine species and 70% of large land animals died out in a very short period of time about 251.4 million years ago. Previously this was thought to be due to exceptionally hot conditions or even ocean chemistry changes.
But now one can see that temperatures actually declined by about 5.0C in a very short period of time (something that is that well-known). This temperature drop exactly coincides with the dating of the Siberian Traps volcanic events at 251 to 250 million years ago which is the largest series of volcanic events known in history. An area nearly the size of Australia may have been covered by volcanic magma flows hundreds of metres deep (some places have been measured at 4 kms deep). The volcanoes lasted for about 1 million years and, not surprisingly, temperatures fell.
The other event is the Ordovician extinction event of 443 million years ago in which 50% of the new Cambrian genera of life disappeared. This was always known to be caused by a cooling climate. But now, one can see that there is a very significant drop in the smoothed temperature estimates exactly at 443 million years ago.
The Devonian Extinction seems to be caused by a rapid increase in temperatures, as much as 10.0C in just a few million years.
Notice how the Cretaceous Period, 95 million years ago, is 2.0C to 3.0C higher than the Paleocene Eocene Thermal Maximum. The climate scientists are always talking about how unusual the PETM was but just a few million years earlier, temperatures were quite a bit higher. Dinosaurs even lived in Alaska at the time, and it was a little farther north in the period than it is now. The PETM event does not even look unusual enough in the record to spend much time on.
Notice that the timelines surrounding the Carboniferous Ice Age and the Ordovician-Silurian Ice Age are now clearly defined. These timelines match up very closely with the estimated alignment of the Continents during the periods. Even the short mid-Jurassic Ice Ages are now evident at a point in time when parts of EuroAsia were transiting the North Pole.
Detailed Temperature Estimates Over the Past 67 million Years
Zachos has developed another database of 14,800 individual estimates of dO18 isotopes that covers the past 67 million years with a resolution of less than 100,000 years in most cases.
The time period when Antarctica glaciated over (for the fourth time that is known about) is clearly evident. Temperatures reached as high as 6.0C during the PETM and the periods when Antarctica reglaciated and when Greenland’s glaciers started building occurred at 14 million years ago.
About 2.5 million years, the most recent cycle of ice ages began. In part II of the series, we may take a closer look at the ice ages in more detail.
PaleoCO2 Estimates
There are quite a few different estimates for CO2 in the PaleoClimate. We have the ice cores, we have Mark Pagani 2005 with high resolution estimates between 5.4 million years to 44.5 million years ago and we have Berner’s GeoCarb III estimates which go back to 570 million years ago.
There are others (and they have been included in the CO2 spreadsheet) but they are not as well-accepted as these. The other estimates come mainly from Stomata size (the cells that plants to use to absorb CO2), Paleosols (ancient soil deposits) and Phytoplankton among others.
Using the estimates that are most accepted and given the resolution is higher with the ice cores than with Pagani and then Pagani’s resolution is higher than Berner’s, they have been incorporated back-to-back-to-back as one series as follows.
As most of you are aware, CO2 goes as high as 7,069 ppm 520 million years ago and as low as 180 ppm during the height of the ice ages.
On the same timeline as the PaleoTemperatures Over 67 Million Years chart above, CO2 looks like this over the past 70 million years.
Paleo Sea Level Estimates
Sea level has also been included in the databases since it is not well-known that these high resolution estimates exist. In addition, sea level can certainly have an impact on the climate as well be an indicator for the climate.
There are many different sea level estimates and the most recent one covering the whole period, produced by the world-leading expert on sea level, Bilal Haq, is the most accepted version (Haq, Schutter, 2008).
Sea Level has varied by a large amount throughout history. Sea levels were as much as 265 metres higher than today 100 million years ago and have been as low as 120 metres lower than today during the Last Glacial Maximum.
Sea level seems to vary through three different mechanisms.
- Sea level falls when glaciers build up on land. Obvious enough.
- Sea level falls when continental land masses are concentrated together. Collisions and mountain building tend to squeeze the Earth’s landmasses together and there is less continental shelf area that can affect the average depth of the overall oceans. Related to the last reason, the ocean basins tend to be more mature and deeper in these situations. and,
- Sea level rises when new young ocean basins are opening. New ocean basins generally form at only 2,500 metres depth while mature ocean basins tend to deepen and reach a depth of about 6,000 metres after 100 million years. That means the overall average depth of the ocean is lower when new oceans are forming. This is particularly the case during the Cretaceous when the Atlantic Ocean was just opening up.
Sea levels rose so high during the Cretaceous as the Atlantic was just opening, that the ocean flooded North America from Texas to Inuvik, to Hudson Bay. Europe, the Middle East, North Africa and the central parts of Eurasia were also flooded by shallow oceans.
During the Carboniferous and the Jurassic, the land masses were collected together into the Supercontinent of Pangea. Sea levels fell in the earlier part as glaciers covered large parts of Gondwana, but then they stayed low as the glaciers melted and the continents moved together to form Pangea.
There are periods when there are rapid changes in sea level and these have been used by researchers to date the periods of glaciations. It appears Scotese has used earlier versions of the sea level data to date the glaciations used in his temperature reconstruction.
Conclusion
Putting all the best estimates together, here is a view of the Temperatures, CO2 and Sea Level throughout the past 526 to 570 million years.
In subsequent posts, we may look at the Milankovitch Cycles and the recent ice ages, Continental Drift through time and how that may have affected the climate and then the empirical evidence surrounding the CO2 doubling sensitivity in the PaleoClimate.
The main purpose of this post was to just make the data available to everyone. Others are free to use to use this data in any manner they see fit.
The data is available in three different easy-to-use Excel spreadsheets and can be downloaded at this link. The Paleo Temp Database is a very large file and may be a slow download.
[Paleo Temp CO2 Sea Level Data]
PaleoClimate Temperature, CO2 and Sea Level Estimates
Guest Post by Bill Illis
This post is the first of what will likely be a series on the PaleoClimate.
In this part, we are just going to go through the various estimates for Temperature, CO2 and Sea Levels in the PaleoClimate. This post is also about making the data available to everyone so that others can use it. All of the data presented in this post is available for download at the end in easy to use Excel spreadsheets which also incorporates direct links to the actual data sources used.
PaleoClimate Temperature Estimates Over the Past 570 Million Years
There are various sources we can use for estimates of Temperatures in the PaleoClimate.
We have the ice core dO18 
isotope data going back 800,000 years. James Zachos has a high resolution database of dO18 isotopes going back 67.0 million years. Jan Veizer has accumulated an isotope database that goes back 526.5 million years. Dana Royer and Robert Berner applied a ph-correction factor to Veizer’s database and Christopher Scotese has developed Temperature estimates that extend back into the pre-Cambrian.
For the most part, the Temperature estimates are based on dO18 isotopes and these have proven to be reasonably reliable, or more accurately, to be the most reliable temperature estimation method that is available.
The isotope data does require a number of different transformations and smoothing to make it useful as a Temperature proxy. Nobody is really sure what the proper way to carry this out is.
For one, it must be detrended as the data becomes older. The dO18 declines over time due to the radioactivity of the Earth. The above estimates are based on a simple linear detrending formula. The rationale is that the radioactive conditions would have remained reasonably constant over the last 530 million years. Others have used a second order polynomial but this does not result in much difference.
It has been noted that the dO18 isotope data should also be corrected for ice volume, sea level, the concentrations of CaCO3 in the oceans and -ph conditions of the oceans. Royer and Berner applied a ph-correction factor based on Berner’s GeoCarb III CO2 estimates. Again, this doesn’t make much difference except that Royer and Berner’s numbers are now lower than Veizer’s original database would point to.
Effectively, any transformation carried out has still got to match the record that we know about. It is still going to have to show a Carboniferous ice age, an Ordovician ice age, a hot Permian Pangea climate, a hot Cretaceous period, an Antarctic glaciation and the recent ice ages.
In other words, no matter what corrections are applied, one should just end up with something very similar to the above chart.
Detailed Temperature Estimates Over the Past 530 Million Years
Veizer’s database contains over 16,600 individual dO18 isotope data points extending back 526.5 million years. There is sufficient resolution throughout the database that we can be reasonably certain about any specific period.
The above chart has been constructed using Veizer’s data with two different smoothing parameters; a shorter one which preserves more detail and then one that emulates the Phanerozoic Climate Change chart by Robert Rohdes of Global Warming Art. It is likely that both are reasonably accurate and sometimes less smoothing is preferred to more smoothing so that more information can be extracted.
In this case, there really is more information available from the shorter Gaussian smooth. Immediately evident is that certain large temperature changes coincide with some of the large Mass Extinction events in the planet’s history.
The really unusual one is the Permian Extinction event in which 96% of marine species and 70% of large land animals died out in a very short period of time about 251.4 million years ago. Previously this was thought to be due to exceptionally hot conditions or even ocean chemistry changes.
But now one can see that temperatures actually declined by about 5.0C in a very short period of time (something that is that well-known). This temperature drop exactly coincides with the dating of the Siberian Traps volcanic events at 251 to 250 million years ago which is the largest series of volcanic events known in history. An area nearly the size of Australia may have been covered by volcanic magma flows hundreds of metres deep (some places have been measured at 4 kms deep). The volcanoes lasted for about 1 million years and, not surprisingly, temperatures fell.
The other event is the Ordovician extinction event of 443 million years ago in which 50% of the new Cambrian genera of life disappeared. This was always known to be caused by a cooling climate. But now, one can see that there is a very significant drop in the smoothed temperature estimates exactly at 443 million years ago.
The Devonian Extinction seems to be caused by a rapid increase in temperatures, as much as 10.0C in just a few million years.
Notice how the Cretaceous Period, 95 million years ago, is 2.0C to 3.0C higher than the Paleocene Eocene Thermal Maximum. The climate scientists are always talking about how unusual the PETM was but just a few million years earlier, temperatures were quite a bit higher. Dinosaurs even lived in Alaska at the time, and it was a little farther north in the period than it is now. The PETM event does not even look unusual enough in the record to spend much time on.
Notice that the timelines surrounding the Carboniferous Ice Age and the Ordovician-Silurian Ice Age are now clearly defined. These timelines match up very closely with the estimated alignment of the Continents during the periods. Even the short mid-Jurassic Ice Ages are now evident at a point in time when parts of EuroAsia were transiting the North Pole.
Detailed Temperature Estimates Over the Past 67 million Years
Zachos has developed another database of 14,800 individual estimates of dO18 isotopes that covers the past 67 million years with a resolution of less than 100,000 years in most cases.
The time period when Antarctica glaciated over (for the fourth time that is known about) is clearly evident. Temperatures reached as high as 6.0C during the PETM and the periods when Antarctica reglaciated and when Greenland’s glaciers started building occurred at 14 million years ago.
About 2.5 million years, the most recent cycle of ice ages began. In part II of the series, we may take a closer look at the ice ages in more detail.
PaleoCO2 Estimates
There are quite a few different estimates for CO2 in the PaleoClimate. We have the ice cores, we have Mark Pagani 2005 with high resolution estimates between 5.4 million years to 44.5 million years ago and we have Berner’s GeoCarb III estimates which go back to 570 million years ago.
There are others (and they have been included in the CO2 spreadsheet) but they are not as well-accepted as these. The other estimates come mainly from Stomata size (the cells that plants to use to absorb CO2), Paleosols (ancient soil deposits) and Phytoplankton among others.
Using the estimates that are most accepted and given the resolution is higher with the ice cores than with Pagani and then Pagani’s resolution is higher than Berner’s, they have been incorporated back-to-back-to-back as one series as follows.
As most of you are aware, CO2 goes as high as 7,069 ppm 520 million years ago and as low as 180 ppm during the height of the ice ages.
On the same timeline as the PaleoTemperatures Over 67 Million Years chart above, CO2 looks like this over the past 70 million years.
Paleo Sea Level Estimates
Sea level has also been included in the databases since it is not well-known that these high resolution estimates exist. In addition, sea level can certainly have an impact on the climate as well be an indicator for the climate.
There are many different sea level estimates and the most recent one covering the whole period, produced by the world-leading expert on sea level, Bilal Haq, is the most accepted version (Haq, Schutter, 2008).
Sea Level has varied by a large amount throughout history. Sea levels were as much as 265 metres higher than today 100 million years ago and have been as low as 120 metres lower than today during the Last Glacial Maximum.
Sea level seems to vary through three different mechanisms.
· Sea level falls when glaciers build up on land. Obvious enough.
· Sea level falls when continental land masses are concentrated together. Collisions and mountain building tend to squeeze the Earth’s landmasses together and there is less continental shelf area that can affect the average depth of the overall oceans. Related to the last reason, the ocean basins tend to be more mature and deeper in these situations. and,
· Sea level rises when new young ocean basins are opening. New ocean basins generally form at only 2,500 metres depth while mature ocean basins tend to deepen and reach a depth of about 6,000 metres after 100 million years. That means the overall average depth of the ocean is lower when new oceans are forming. This is particularly the case during the Cretaceous when the Atlantic Ocean was just opening up.
Sea levels rose so high during the Cretaceous as the Atlantic was just opening, that the ocean flooded North America from Texas to Inuvik, to Hudson Bay. Europe, the Middle East, North Africa and the central parts of Eurasia were also flooded by shallow oceans.
During the Carboniferous and the Jurassic, the land masses were collected together into the Supercontinent of Pangea. Sea levels fell in the earlier part as glaciers covered large parts of Gondwana, but then they stayed low as the glaciers melted and the continents moved together to form Pangea.
There are periods when there are rapid changes in sea level and these have been used by researchers to date the periods of glaciations. It appears Scotese has used earlier versions of the sea level data to date the glaciations used in his temperature reconstruction.
Conclusion
Putting all the best estimates together, here is a view of the Temperatures, CO2 and Sea Level throughout the past 526 to 570 million years.
In subsequent posts, we may look at the Milankovitch Cycles and the recent ice ages, Continental Drift through time and how that may have affected the climate and then the empirical evidence surrounding the CO2 doubling sensitivity in the PaleoClimate.
The main purpose of this post was to just make the data available to everyone. Others are free to use to use this data in any manner they see fit.
The data is available in three different easy-to-use Excel spreadsheets and can be downloaded at this link. The Paleo Temp Database is a very large file and may be a slow download.
[Paleo Temp CO2 Sea Level Data]
Gacooke (15:52:45) : are you only interested in the last 6000 years?
That is a statement (accusation) of a childish mind.
When discussing past climate, most scientists use a scale with benchmarks in the thousands or greater. You seem to think that scales using years as a benchmark are comparable. If one were to look back at our current climate 70 million years from now it wouldn’t even be noticed.
Just because someone said the sky was orange doesn’t mean we have to come up with numerous studies to prove that it is in reality blue.
I have addressed the issue of global warming along with a myriad of other topics. I would appreciate your look and comment. Thanks http://www.donottreadonus.wordpress.com
Well, I’ve reread your posts, gtrip, and beyond the idea that you see no value in the material presented in this thread, I am unable to divine your point. I find this material useful and informative on a number of levels.
The link you provided was to an interesting screed of a typical AGW skeptic. Thanks for that, anyway.
I’ll make no more “childish” guesses about your point of view.
Very nice. Especially that data all in nice Excel form. Thanks.
Gacooke (15:52:45) : are you only interested in the last 6000 years?
gtrip (16:17:49) That is a statement (accusation) of a childish mind.
I was puzzeled by this. Now I get it. I was referring to the time since the start of the current sea level high stand at or around the beginnings of recorded history. Nothing more.
Benjamin P. (09:30:48) :
Tectonics is not my specialty, but… I don’t think there’s any correlation between sea floor spreading rates and sea level…
Phanerozoic Sea Level Cycles
Don’t ever take a college-level course in geology, unless you like getting “F’s”.
The geological processes of the modern world have been the same geological processes that occurred throughout Earth’s history… And, despite using different materials, the geological processes on Titan are remarkably similar to those of Earth.
The Earth doesn’t all of the sudden start behaving differently than it has over the last 600 million years, or so, because mankind increases the global carbon budget by, at most, 3%. Anthropogenic CO2 emissions are, at most, a rounding error to the Earth’s dynamic climate.
Hey Dave. I’ll add that the study of geologic information reveals a mixture of uniformitarian and catastrophic processes. Positive feedback tipping points do exist.
I know of no reliable study that demonstrates a catastrophic tipping point will be reached by increasing atmospheric CO2 by a couple of hundred parts per million (v/v).
To Dr. Burns et. al.:
The argument on this discussion is simply this: Nobody disputes that Earth has gone through huge climate swings in the past. And given slow rates of change (say 4 Deg in 10.000 years) we can likely adapt. But 4 Deg in a century would if it happens constitute a catastrophe for the current human endeavor and the current ecosystem.
The work presented here, while nicely compiled, is irrelevant in the current discussion weather we will see warming to this extent due to human activities or not. And if we do, what if anything we should do about it.
The argument of the author is a bit like a feel-good one: Earth has ‘coped’ with more extreme temperatures and sea levels in the past – ergo she will be all right whatever happens. This of cause is nonsense within the horizon of our own human civilization and especially at our present situation on an exponential overhsoot trajectory in population numbers and resource depletion.
For arguments about my own convictions about the current warming outlook I refer to http://www.realclimate.org/
I put sea level estimates into the datasets primarily because most people don’t know this data is available.
That and it can provide some indication of climatic conditions.
The Phanerozoic Sea Level Cycle chart linked to by Dave Middleton above is available in the sea level spreadsheet in higher resolution as the Exxon/Vail sea level curve. While this is an older dataset and was really the first one (and even shocked some that such information could be put together), some people still consider it to be the most accurate.
The real impact as far as the climate is concerned is, can we use sea level to estimate temperatures or general climatic conditions. Not really since it varies by a large amount even depending on continental drift and other conditions.
What it does help with, however, is explaining why certain periods were as warm or as cold as they were. The Cretaceous period, for example, around 100 million years ago was very warm/hot. Shallow oceans covered the interior of North America and all of Europe and one could even imagine a warm shallow ocean current flowing from the Gulf of Mexico to the Arctic Ocean. There was no sea ice at the time and Dinosaurs even lived in Alaska at 75N. It was warm. CO2 levels were not that high and can’t really explain the temperature conditions. But the Albedo of the planet was certainly lower at the time given there was no ice and an additional amount of shallow ocean (which has a lower Albedo) covered large parts of the continents.
It can also help with certain cold periods in that sea level falls as more ice is locked up on land so it provides some indication of when those periods occured.
Samoht:
Yes, we know about realclimate.
Most of us sharply dispute that temps will change 4C in a century because we do not accept the current positive feedback theory as realistic.
(Note, however, that the Younger Dryas is believed to have ended with a 10C upshift in less than a decade.)
Samoht (18:14:10) :
The argument of the author is a bit like a feel-good one: Earth has ‘coped’ with more extreme temperatures and sea levels in the past – ergo she will be all right whatever happens.
Actually, that is not what the post says. It does say there at least 3 mass extinction events that might be linked to rapid changes in the climate.
The question is, is CO2 also linked to those events. Well, No.
CO2 doesn’t seem to be involved at all. There is not a single instance of major climatic change or extinction events linked to CO2 at all.
Samoht (18:14:10) says:
“The argument of the author is a bit like a feel-good one: Earth has ‘coped’ with more extreme temperatures and sea levels in the past – ergo she will be all right whatever happens.”
I didn’t see that anywhere in the OP. Perhaps you can quote where that was said?
OP does say:
“This post is the first of what will likely be a series on the PaleoClimate.
In this part, we are just going to go through the various estimates for Temperature, CO2 and Sea Levels in the PaleoClimate. This post is also about making the data available to everyone so that others can use it.”
I saw no other statement of purpose.
Ascribing your convictions to a single political climate blog is rather restricting. There are broader horizons out there.
If population growth and resource depletion are the problems, then they should be confronted. Not the scapegoat CO2.
Re: Dave Middleton (17:36:38) :
As the sea floor moves from the mid-ocean ridges it cools and becomes more dense and it sinks. Therefore a rapid spreading rate is postulated to result in a sea floor that is higher than than it would be if there were a slow sea-floor spreading rate. In other words the bottom of the basin rises and the sea level also rises.
The rapid spreading rates as the Atlantic Ocean formed are thought to be the cause of the higher sea levels in the Mesozoic and the resulting North American Inland seaway.
Thanks to E. J. Mohr (18:47:22) for your response to Dave Middleton (17:36:38)!
Bill Illis: I see no proof whatsoever from these data that show that CO2 is not a climate forcing GH gas and this article while well presented is not adding to that discussion.
What the press and the general public however takes from discussions like this is the simplified message: ‘Its all natural, the Earth was once already much warmer and coped with high CO2 concentrations, so lets carry on with business as usual’. And that I would think is the intended outcome of this blog and probably some of the commentators here.
Gacooke: I do not subscribe my convictions to a single climate blog and I suppose neither do you. Doing so would be nuts. But I find it tiresome to rehash all the arguments again and again and http://www.realclimate.org/ is doing in excellent job in debating and summarizing the issue as I see it.
evanmjones: The events of the Younger Dryas are very interesting indeed. What exactly is your argument though in regards of today’s climate debate? Because the Earth coped with rapid swings in the past (a fast end to a glaciation period) we today will be fine with a 4Deg temp rise in a century? I miss the connection.
For our civilization and the debate what we should do about our CO2 emissions the record of the past
For our civilization and the debate what we should do about our CO2 emissions the record of the past is particularly important over the last several hundred thousand years.
Samoht:
I’m a lukewarmer. My current position is that there has been some warming over the 20th century, perhaps exaggerated by a number of measurement biases. I believe some of the increase is natural and some anthropogenic. I believe some of the anthropogenic increase is due to non-CO2 issues such as deforestation, land use, and soot.
Even if current trends continue, we can expect less than a 1C rise by 2100. Wild swings are not impossible, but instead of positive feedback from ambient vapor, we seem to be observing negative feedback from increased albedo from increased low-level cloud cover.
As for a 4C rise (not good), I think a 4C drop would be much worse. Anything is theoretically possible. But either of those seems quite unlikely.
As for the future, we must develop as quickly as possible, creating as much wealth as possible along the way, while avoiding direct environmental destruction (but not worrying about CO2). If we do this, mankind will become incredibly powerful and will have problem-solving capabilities (environmentally and otherwise) we cannot conceive of today. Meanwhile, we must not kill the golden goose.
Samoht (19:28:42) :
Bill Illis: I see no proof whatsoever from these data that show that CO2 is not a climate forcing GH gas and this article while well presented is not adding to that discussion.
What the press and the general public however takes from discussions like this is the simplified message: ‘Its all natural, the Earth was once already much warmer and coped with high CO2 concentrations, so lets carry on with business as usual’. And that I would think is the intended outcome of this blog and probably some of the commentators here.
Samoht, the intended impact is to demonstrate what the empirical evidence says. There is currently climate models and theory. It is clear that CO2 is a greenhouse gas and that it has a radiative impact on surface temperatures. How much is the question. Is it 3.0C per doubling, 6.0C per doubling or is it less.
Do you not want to know?
Do you not want to know what has happened historically per CO2 doubling. I always have. Whatever comes out of it doesn’t automatically mean we should build coal-fired power plants every 100 kms. But it will provide another line of evidence which could support or not support the assertions of the climate models.
I found a very interesting statement in a military book on Infrared radiation that I purchased in a book store (funded by ARPA in 1962). The statement was about CO2 concentrations. It had the global average of CO2 at 330 ppm in 1962 for starters which contradicts the Mauna Loa data but also it said:
CO2 concentrations vary between 200-600 ppm from the surface of the Earth to a few hundred feet in altitude. That is a hell of a variance in concentration. Is that why the sensor that is used at Mauna Loa is at the altitude that it is? Has anyone else read this or know of this result? If so, it is an amazing contradiction to the computer models that model a uniform distribution of CO2.
I trust the results laid out in this book as ALL of the absorbers in the infrared were extensively studied back then in order to allow for the design of the heat seeking missiles that the U.S. has built and used with such success for several decades.
Dennis Wingo (20:18:30) said:
Does it have a name, ISBN, etc. Perhaps Google has indexed it. Perhaps it is (partially) available on line.
REPLY: I found out where to order a copy here:
http://www.ntis.gov/search/product.aspx?ABBR=AD646082
– Anthony
evanmjones: I agree with you that we must not kill the golden goose. The question is: Who or what is the goose? I think the goose is an environment that is able to sustain life as best as possible with a large species variety etc…
Others see the Golden Goose as money, wealth etc… I am septic there. As far as I can see there is overwhelming evidence that the quest for exponential growth of power, wealth and population has already killed the goose that laid the golden eggs. In the end Maltus will be proven right, as unfortunate as it may be.
Bill Illis: Yes I agree that we need to know what a doubling of CO2 will do to our climate. PaleoClimate studies are important in that quest.
I hear though all to often the false conclusions drawn from this in the public debate to which I took reference.
I am glad we agree on CO2 being a climate forcing agent.
That certainly makes sense and it is possible…
But I think the high Cretaceous sea level was more a function of the distribution of land mass than rate of sea floor spreading. Sea level was fairly stable from the early Pennsylvanian through the end Jurassic; then rose rather abruptly during the Cretaceous. The modern Atlantic Ocean basin began to open in the Triassic and has been spreading ever since.
As I said before, tectonics isn’t my specialty. Is there any evidence that the spreading rate was faster in the Cretaceous than it was before or after?
On a side note: Here’s a cool animation of the opening of the Atlantic Ocean
There are useful analogies throughout the entire Phanerozoic Eon (the last ~600 million years). However, you are correct that the upper Pleistocene and Holocene are the most relevant because the tectonic and orogenic changes over the last 800,000 years, or so, are relatively minor.
The relationship between greenhouse gases and climate during the Pleistocene and Holocene should hold true in the modern world.
The last four Pleistocene interglacials were warmer than the current interglacial. Yet, if the ice core data are correct, all three interglacials had far lower CO2 concentrations. In each and every Pleistocene glacial-interglacial cycle recorded in the ice cores, delta-T always preceded delta-CO2. So the ice core data do not support CO2 as a Pleistocene climate driver. There is an alternate or supplemental way to measure past CO2 changes: Fossil plant stomatal density or Stomatal Index (SI). The plant stomatal CO2 reconstructions indicate that CO2 levels of 320-390 ppmv have been relatively common during warm periods in the Holocene and recent times. The SI data show that the 20th century increase in atmospheric CO2 was no different than the Roman Warming (300 AD to 400 AD).
Furthermore, the warming of the late 20th century was no different in magnitude or rate of change than the early 20th century warming, the Medieval Warm Period or the Roman Warming.
Simply put: The climate and atmospheric changes we are observing today are not anomalous when compared to past changes. There is simply no evidence that mankind’s 1% to 3% contribution to the Earth’s carbon budget over the last 150 years has done anything to measurably alter the Earth’s climate and the geological history Phanerozoic Eon provides little support to the notion that CO2 has ever driven climate change at any time in the last 600 million years.