Carbon release and global warming now and in the ancient past
From the National Oceanography Centre
The present rate of greenhouse carbon dioxide emissions through fossil fuel burning is higher than that associated with an ancient episode of severe global warming, according to new research. The findings are published online this week by the journal Nature Geoscience.
Around 55.9 million years ago, the Earth experienced a period of intense global warming known as the Palaeocene–Eocene Thermal Maximum (PETM), which lasted for around 170,000 years. During its main phase, average annual temperatures rose by around 5°C.
Scientists believe that the warming may have been initially triggered by an event such as the baking of organic-rich sediments by igneous activity that released the potent greenhouse gas, methane. This initial temperature increase warmed ocean bottom waters which allowed the break down of gas hydrates (clathrates), which are found under deep ocean sediments: this would have greatly amplified the initial warming by releasing even more vast volumes of methane. As the methane diffused from the seawater into the atmosphere it would have been oxidised to form carbon dioxide, another potent and longer-lived greenhouse gas.
Adam Charles and his PhD supervisor, Dr Ian Harding, both palaeoceanographers at the University of Southampton’s School of Ocean and Earth Science (SOES) based at the National Oceanography Centre, Southampton, co-authored the report. Dr Harding said: “The PETM has been seen by many as a natural test bed for understanding modern man-made global warming, despite it not being a perfect analogy. However, the total amount of carbon released during this climatic perturbation and its rate of release have been unclear.”
To help fill this gap in knowledge, the researchers measured carbon isotope ratios of marine organic matter preserved in sediments collected in Spitsbergen. The sedimentary section is important because it records the entirety of the PETM, from its initiation to through the recovery period, and as such is the most complete record of the warming event so far known in high northern latitudes.
Based on their carbon isotope measurements and computer simulations of the Earth system, the researchers estimated that the rate of carbon emissions during the PETM peaked at between 300 million and 1,700 million metric tonnes per year, which is much slower than the present carbon emission rate.
“Our findings suggest that humankind may be causing atmospheric carbon dioxide to increase at rates never previously seen on Earth, which would suggest that current temperatures will potentially rise much faster than they did during the PETM,” concluded Dr Harding.
The authors of report published by Nature Geoscience are Ying Cui, Lee Kump, Christopher Junium, Aaron Diefendorf, Katherine Freeman and Nathan Urban (Pennsylvania State University), Andy Ridgwell (University of Bristol), and Adam Charles and Ian Harding (SOES). This research was supported by The Worldwide Universities Network, Pennsylvania State University, and the US National Science Foundation..
Cui, Y., Kump, L. R., Ridgwell, A. J., Charles, A. J., Junium, C. K., Diefendorf, A. F., Freeman, K. H., Urban, N. M. & Harding, I. C. Slow release of fossil carbon during the Palaeocene–Eocene Thermal Maximum. Nature Geoscience (Published online, 5 June 2011). DOI: 10.1038/NGEO1179
Thanks for a very intresting article.
When they get to the “rate of carbon emission” part, I get confused. What are they comparing? Methane and carbon dioxide are very different beasts. Also, the continent configuration was very different at that time – have they ruled out ocean currents as the driving positive feedback mechanism?
They ASSUME that CO2 is the culprit, then turn around and “suggest” that we are at fault. The PETM was also a time of huge biologic activity in the Tethys region, that which eventually gave rise to the immense accumulations of oil and gas in the Middle East. Maybe these fellers should look at GLOBAL isotopes rather than an isolated section in subarctic Svalbard. They should also “suggest” why it was so warm during the Cretaceous….no mention. Pass the platter.
Wikepdia says:
The timing of the PETM δ13C excursion has been calculated in two complementary ways. The iconic core covering this time period is the ODP’s Core 690, and the timing is based exclusively on this core’s record……] Both models have their failings, but agree on a few points. Importantly, they both detect two steps in the drop of δ13C, each lasting about 1,000 years, and separated by about 20,000 years…… There is other evidence to suggest that warming predated the δ13C excursion by some 3,000 years.[15]
While the rate of CO2 input by man is larger than that of the PETM, the event went on for 2-1000 year periods. That lead to a 6C rise. Okay, so say we put in, over 100 years, at three times the event rate, and we have 300/2000 the total input. Or 15%. How about 15% of 6C rise, or 0.90C.
Something wrong with the math? And we can’t do 100 years like that. We don’t have enough fossil fuel.
And note the last line: There is some evidence to suggest the warming predated the [CO2 release] by some 3,000 years.
Taken out of context, again.
We need to unlock all the carbon based sediments to feed the atmospheric methane and CO2. In response, the climate will warm up so as to allow my tropical fruit trees which I rely on for food will grow at 48 deg north. Right?
I understand methane has about an 8 year residence before oxidizing in the atmosphere. Hmm, why wait, it makes great fuel for our energy producers who we all rely on so heavily for cheap power. Right?
Standard atmospheric temperature = 56 F. I think I could do well with 64 F Why not? 🙂
55.9 million years ago, CO2 levels were much higher than at present. It must have been all the cars the dinosaurs were driving. It raised CO2 levels and temperatures and the dinosaurs went extinct. 10 million years later things warmed up from all the CO2 they produced.
Only problem is, CO2 lags temperature. Rising temperatures cause CO2 to rise. Climate “science” predicted the opposite. That would have been sufficient in any real science to discredit the AGW hypothesis. Add to that the predicted “hot spot:” has never been found, 2 nails in the AGW coffin.
If AGW is true, where is the paleo record showing that CO2 triggered a warming? Even this paper says that the increase was perhaps triggered by methane – which is the only explanation they can come up with – because the paper itself says the CO2 increase was less than present!!
So, this paper itself discredits CO2 as a driver of temperature, because you have a large increase in temperature with a small increase in CO2!!
So we are releasing CO2 faster than during the PETM. Okay, so where is the corresponding dramatic warming in excess of the PETM. Oh right, it only exists in computer models.
“Our findings suggest that humankind may be causing atmospheric carbon dioxide to increase at rates never previously seen on Earth…” concluded Dr Harding.
Their findings suggest nothing of the sort.
They must be desperate for more grant money.
The CO2 build up coinciding with the thermal max. is one of the least understood events in geology. The sudden temperature rise did cause massive extinctions in the sea. However it also caused massive biogrowth everywhere of surviving species and eventually the introduction of many new biologic variants that thrived in the balmy climate. The rate of CO2 introduction is still unknown, but it was not remotely comparable to the leisurely pace we are at now. Further, some scientists postulate the ocean warmed independently of the CO2 via intense vulcanism. See e.g., http://geology.gsapubs.org/content/25/11/963.abstract.
Using the unknown to panic is poor science. And that appears to be the sole purpose here.
‘Scientists believe that warming MAY’, ‘despite it not being a perfect analogy’, ‘our findings suggest’. Is there any hard science out there? We are putting more CO2 into the atmosphere than this ancient event but the tempreture isn’t climbing. It’s June and I feel cold. Well, that’s just weather or my age.
I will look at this paper with interest. Firstly, if the natural flux of carbon dioxide was anything like today’s, then the researchers would have to isolate an annual increase at less than 1% the normal flux. But I guess they are mostly concerned with having indentified the rate of change compared to today. I don’t think anyone doubts that industrial emissions are leading to a higher rate of change in CO2 concentrations than anything in the past. The real question is how much of this translates into a radiative forcing when the relationship is logarithmic. Most of the greenhouse ‘work’ of CO2 is done in the first 50 ppmv and the curve has levelled off by 200 ppmv. The 280 ppmv at the end of the ice-age was not enough to prevent natural drops of 5 degrees C in Arctic regions during subsequent Holocene fluctuations. Hence I am doubtful it contributed much to the rising part of the same fluctuations – and indeed statistical analyses of the Greenland ice-core data over the last 10,000 years shows that fluctuations in temperature are not correlated to the rise and fall of CO2.
Since the dawn of industry, we have added another 100ppmv. and are on track for another 200ppmv by 2050. If we extrapolate climate sensitivities calculated from paleoclimatology (and many papers do this) where a figure of 1 degree C per 10ppmv is not unusual…we should have seen 10 degrees C since 1750 where we have only seen about 1 degree. The next 100ppmv will deliver less than this and so on along the curve of that log relationship. Unless, of course, there is a long time lag where the ocean absorbs and releases heat. The paleo-record offers no evidence of such long time lags and modern monitoring shows 80% of the current accumulated anomalous warmth is held in the upper 200 metres and hence readily released.
Journals all-too-readily publish narrow-focussed papers with scary conclusions that support the alarmist concensus despite containing no references to this log-relation or the absurd climate sensivities that result from ignoring that basic physics.
The sedimentary section is important because it records the entirety of the PETM
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So they measured an increase in carbon sequestration when temperatures increased in northern cold waters…..
………..and assumed from that, that atmospheric carbon was a certain level and increase
Without having a clue that nitrification/denitrification increased because it was warmer……………..
I know bio-chemistry is a lot harder than what they tried to do, but for God’s sake get a clue………..
This article has more slosh to it than what I predict my catch will be fishing next Saturday on the Snake River.
“Our findings suggest that humankind may be causing atmospheric carbon dioxide to increase at rates never previously seen on Earth…” concluded Dr Harding
In fact 59,9 million years represents about 1,5% of the age of the Earth.
If I made such wild extrapolations from the known facts at work, I would get fired
Billy Liar said, quoting the article, “Our findings suggest that humankind may be causing atmospheric carbon dioxide to increase at rates never previously seen on Earth…” concluded Dr Harding.
Then Billy responded:
“Their findings suggest nothing of the sort.”
Ah, but they used the magic word “rates.” It’s the rate of change that annoys them and they average it over the 170,000 years of the PETM. Of course, they have no clue if sudden spikes occurred during the release of clathrates or that those “CO2 producing” volcanic activities more likely produced huge volumes of SO2 which caused sudden cooling at rates not seen since.
A little knowledge is a dangerous thing, especially if you already know the answer before asking the question.
“Scientists believe,… findings suggest” = Theory
Public policy and taxes must never be based on theory.
Deccan Traps at play?
Funny, It rose 5C and there was no runaway greenhouse effect? While he tries to go out and scream about how it worse than it was before, he inadvertently tells us there is nothing to worry about. No runaway climate, just a slow to adjust toward optimum climate.
CO2 cannot possibly cause that much temperature change. Take a look at the PETM chart at http://en.wikipedia.org/wiki/File:65_Myr_Climate_Change.png and remind yourself of the relationship between CO2 concentration and temperature increase ( http://3.bp.blogspot.com/-rdcOaKHttG0/TW8NGiOvBVI/AAAAAAAACLM/Ahj60UxeKN4/s1600/co2greenhouse-X2.png )
Then take a look at CO2 versus temperature in the early Tertiary (Paleocene-Eocene) at
http://www.geocraft.com/WVFossils/PageMill_Images/image277.gif
What would possess an oceanographer to ignore basic physics and geologic findings? Surely they knew that the whole “science” of climate change dissolves if you understand the geologic record.
“Our findings suggest that humankind may be causing atmospheric carbon dioxide to increase at rates never previously seen on Earth, which would suggest that current temperatures will potentially rise much faster than they did during the PETM,” concluded Dr Harding.
Or that CO2 is not nearly as powerful a forcing agent as he thinks, concluded everyone else.
Our findings suggest…humankind may…Scientists believe…warming may…has been seen by many…not being a perfect analogy…have been unclear…the researchers estimated…Our findings suggest…humankind may…which would suggest…will potentially rise much faster than they did during the PETM”
Well, why didn’t you say so!
Just toss taht list of 900+ skeptic supportive papers and let’s go with Dr’s May, Suggest and Believe et al.
If, and when if, could have, then it would, causing, this may have, also possible, if, and only if, if, if, by using this with simulators scientists have now found that if if, and if, if it could happen then, it might happen now. To prevent all these ifs they suggest a tax to compensate Africans.
I get it..
RockyRoad says:
June 9, 2011 at 10:02 am
I agree I was just looking at the snake near the town of ST. Anthony and the slosh there could wipe out several bridges from all the global warming caused snow in the mountains.
They average 170 000 years of data from 55 point 9 million years ago (with highly questionable resolution) with todays about 100 years of average data of rather high resolution. Essentially, they skipped a class or two?
pat said @ur momisugly June 9, 2011 at 9:44 am
“The CO2 build up coinciding with the thermal max. is one of the least understood events in geology.”
Agree…
“The sudden temperature rise did cause massive extinctions in the sea.”
I thought this applied only to benthic organisms in the north Atlantic, but stand ready to be corrected. I also thought this “mass” extinction was caused by the water becoming anoxic due to changes in oceanic circulation in turn caused by changes to the continental configuration.
“However it also caused massive biogrowth everywhere of surviving species and eventually the introduction of many new biologic variants that thrived in the balmy climate.”
The Git notes that two of the major speciations occurring at that time were the arrival of the first whales (so much for mass-extinction in the sea, and primates. The Git is rather fond of primates 🙂
[snip]
“Using the unknown to panic is poor science. And that appears to be the sole purpose here.”
In my youth we used to call “Using the unknown to panic” telling ghost stories. It never occurred to us to associate this with science, poor or otherwise…