Carbon isotope ratios are central to many reconstructions of past climate. For example the IPCC Working Group 1 cited C12/C13 ratios as the basis for determining some of their findings about climate in the last 1000 years. However, longer term reconstructions are less certain, and now with this new discovery, some of the long term work may have to be reconsidered.
From the primary researcher, “This study is a major step in terms of rethinking how geologists interpret variations in the 13C/12C ratio throughout Earth’s history. If the approach does not work over the past 10 million years, then why would it work during older time periods? As a consequence of our findings, changes in 13C/12C records need to be reevaluated, conclusions regarding changes in the reservoirs of carbon will have to be reassessed, and some of the widely-held ideas regarding the elevation of CO2 during specific periods of the Earth’s geological history will have to be adjusted.”
While this research doesn’t necessarily throw carbon dating out the window, it should cause people to rethink so many theories about early life that revolved around ages of sediment in the oceans.
Here is the full study, there is a link to the PDF on the upper left but they want $10 to access it.
http://www.pnas.org/content/early/2008/09/03/0802841105
Anthony Watts,
As a near original ‘lurker’, really big fan and recent poster I want to call your attention to what is going on at Climate Audit. Ian Jolliff has recently refuted the statistical analysis used to create the hockey stick graphs of mann et everyone AGW. I know you already are aware of this from your consistent up to date posts but this can’t be swept under the rug by the media without a fight.
While the rest of the media focuses on polarbears who need waterwings I feel strongly that those of us who believe there is reason to be skeptical, need to explain to the public what has happened.
I am requesting you review the significance of this event. When we are inundated with AGW news there is rarely a reply. This is no small opportunity. I have published a short article to explain. You can do a much better job getting the news out, I’m sure!
http://noconsensus.wordpress.com/2008/09/12/global-warming-takes-a-shot-in-the-globes/
REPLY: Hello Jeff, many people don’t know this, but I’m more in-sync with CA than you can imagine. It’s my server. I set it up for Steve last year when he was having trouble. With Steve it is a series of steps towards understanding as thr layers are peeled back on the complex reconstructions in Mann-world. The challenge is to condense it to something the layman can understand. I’ve found it prudent to wait before I publish on this, since Steve will likely remove another layer shortly.
I will examine your article and see if it couldn’t be useful. Thank you for the opportunity. – Anthony
Anthony
I think it would be better in your piece to call this something like “carbon isotope correlation” rather than “Carbon dating”. This is because the term “carbon dating” relates strictly to the 14C isotope rather than 12C and 13C. Carbon dating is a radiometric method because 14C is radioactive with a half life of around 5600 years or so. Whereas 12C and 13C are not radioactive. Dating by 14C is only feasible back to a maximum of about 60,000 years, and even then only under special circumstances.
REPLY: Good point, I’ve changed the wording. – Anthony
I attended a presentation by an IPCC lead author tonight who showed the hockey stick to about a thousand people, and described it as “well established science.”
Global warming is causing heavy rain in Australia, which is suffering a severe global warming induced drought.
http://news.bbc.co.uk/2/hi/technology/7610786.stm
NOTE TO MODERATOR: This comment relates to the closed theme about sacking Dr Hanson, which included reference to the recently concluded trial of the vandals at a power station. As you will see my comment is about the trial, not about Dr Hanson. A number of comments questioned the right of the jury to return the verdicts they did. Yesterday I wrote an entry in my little blog about this and I think it might be of interest to them. I know it is way off topic for this thread, but I wonder whether you might allow me to make my comment here. I understand entirely if you would prefer to draw a line under that thread. If you would rather not raise the issue again please do not trouble to email me, merely not publishing my comment will be sufficient indication. FB.
What I would like to say is this:
Some of you have questioned how the jury here in the UK could have acquitted those accused of criminal damage to a power station. I hope this helps to explain:
http://thefatbigot.blogspot.com/2008/09/is-gordon-criminal-damage.html
Carbon dating? Oh, my…
http://www.theonion.com/content/news/evolutionists_flock_to_darwin
OT: spaceweather has a sunspeck, better look before it disappears!
Isn’t it possible that with this they might want to “remove” the inconvenient 800 years lag in CO2 records?
Oh, my…
That’s a hoot and a half!
With regard to the post by Patrick Henry about weather in Australia spoiling a record attempt by a wind powered ‘car’. A quote by one of the Greenie drivers amused me……
“In the next 20 years, I firmly believe that wind power will be our main energy source and wind-powered cars will no longer be the stuff of dreams.”
Well don’t hold your breath pal……….
Australia is always haveing a drought, sever or otherwise. Pointing at Australia and saying drought proves nothing. They should already know this, but it makes good press.
crosspatch (23:06:28) :
OT: spaceweather has a sunspeck, better look before it disappears!
Is your monitor warrantied for dead pixels? There aren’t any corresponding zits on the magnetogram, or EIT, even at full scale.
I’ll admit watching the sun has been pretty boring lately. Gonna buy me a thick sweater this winter.
I’ve read the paper, and while it is important it has nothing whatsoever to do with dating. I suggest you change the wording. Also it has little or nothing to do with CO2 in ice cores as suggested above.
Corbon has different 12C/13C ratio depending on whether it is organic or not. For example carbon from organic CH4 is very light (=high 12C/13C ratio).
At some periods in the past there are large perturbations in the carbon isotope ratio, which have been interpreted as indicating serious disturbances in the carbon cycle. This is true for example for the Permian/Triassic extinction and the PETM (Paleocene/Eocene Thermal Maximum). This has been interpreted as being caused by large-scale melting of methane hydrates, causing catastrophic greenhouse warming. What this study implies is that excursions in shallow-water deposits may be due to sea-level rise instead. So it may actually be a result of rising temperatures rather than a cause.
FatBigot (22:43:11): Thank you for those thoughts posted on your blog. I found them enlightening and providing of much to mull.
@DEE NORRIS
ive free acces to the pnas article.
i could mail it to you if you want.
regards
rutger
Reply – Thank you. I will be contacting you shortly. From reading the abstract, I get the feeling that Science News didn’t really get the facts straight. They seem to be saying that variations in the sea level cause different types of sedimentation which affect the C12/C13 ratios where previously, it was assumed to be consistent. – Dee Norris
from the article
Despite the assumption made by numerous workers that the
13C values of these sediments are related to the global carbon
cycle, and that they can be used both as a proxy for the burial of
organic material (15) and as a stratigraphic tool (20), several
studies have proposed that changes in the 13C of carbonate
rocks might not be related to variations in the global organic
carbon cycle. For example, it has been suggested that variations
in the 13C of carbonate sediments deposited in epeiric seas are
related to local recycling of organic material, rather than to
changes in the global carbon cycle (18, 21–23).
[…] Rethinking Carbon of the Past: Scientist Uncovers Miscalculation …A new study examines changes in carbon isotope ratios over the past 10 million years at sites off the Bahamas (Atlantic Ocean), the Maldives (Indian Ocean), and Great Barrier Reef (Pacific Ocean). (Credit: NASA) … […]
and the science is still not settled.
All
Is there a definitive (yes I know I may be asking too much) paper, or papers, on the atmospheric lifetime of CO2?
I ask because there are ludicrous figures bandied about for anthropogenic CO2 (thousands of years) yet John Daley has laid it out as much, much less than ridiculous.
Thanks in advance.
FatBigot – thanks for the input. Hope you enjoyed you time in The States.
@DEE NORRIS
ive free acces to the pnas article.
i could mail it to you if you want.
I do not think that your ‘free access’ to this article is intended as free access to those to whom it is not intended. I also have ‘free access’ to similar articles because my university fees pay pnas but, it is unethical to pass these articles around without compensation to pnas.
I don’t know and that’s why I’m asking… Was this study funded by our tax dollars?
@rasmin
as long as its for non-profit use, i think its alright
Can others (nonauthor third parties) use my original figures or tables in their works without asking PNAS for permission?
Yes, PNAS automatically permits others to use your original figures or tables published in PNAS for noncommercial and educational use (i.e., in a review article, in a book that is not for sale), provided that the original source and copyright notice are cited. Commercial reuse of figures and tables (i.e., in promotional materials, in a textbook for sale) requires permission from PNAS.
Can the news media use my figures without asking PNAS for permission?
Yes, journalists may use original figures from your PNAS article to illustrate news stories. Written permission from PNAS is not required; however, all figures should be cited as copyright Proceedings of the National Academy of Sciences USA . Figures may not be used to illustrate news stories unrelated to a given PNAS article without express written permission from PNAS. To obtain high-resolution versions of figures, PNASnews@nas.edu.
According to this study, it’s not sunspot numbers alone that determine the sun’s influence on climate, but total geomagnetic activity. Sunspot number has been dropping, but what about total geomagnetic activity?
http://sait.oat.ts.astro.it/MSAIt760405/PDF/2005MmSAI..76..969G.pdf
did you see you made the news?
http://sciencedude.freedomblogging.com/2008/09/12/has-santa-ana-been-reporting-wrong-temperatures-for-years/
John M Reynolds
Anothony, you were mentioned in my local newspaper.
http://sciencedude.freedomblogging.com/2008/09/12/has-santa-ana-been-reporting-wrong-temperatures-for-years/