The new study extending the temp record back to 11,0oo years has gotten a lot of press.
I don’t read or speak Dutch, but a Dutch blogger has extended the graph forward a century, and backward to the last glacial period. I expect this will be translated into english, and will provide more info when I see it. If anyone wants to try google translate to make sense of it, by all means.
Powerful image of the anthropocene, though.
The Anthropocene is an informal geologic chronological term that serves to mark the evidence and extent of human activities that have had a significant global impact on the Earth‘s ecosystems. The term was coined recently by ecologist Eugene F. Stoermer, but has been widely popularized by the Nobel Prize-winning atmospheric chemist, Paul Crutzen, who regards the influence of human behavior on the Earth’s atmosphere in recent centuries as so significant as to constitute a new geological epoch for its lithosphere. To date, the term has not been adopted as part of the official nomenclature of the geological field of study.
UPDATE – a reader sends in this translation from the Chrome browser:
Guest Blog by Jos Hage Boot
Starting in March 2013 appeared in Science an article about a temperature reconstruction for the last 11,000 years . The lead author is Shaun Marcott from Oregon State University and the second author Jeremy Shakun, which we know from the previous year published and interesting research on the relationship between CO2 and temperature during and after the end of the last ice age. Temperature reconstruction of Marcott is the first full period of the Holocene covers. Obviously not perfect and the coming years will probably details on what changed. A normal part of the scientific process.
The temperature reconstruction ends mid century, therefore, in the graphs of their study the rapid temperature rise after 1850 is clearly visible. And what do you find? Again something that looks like a hockey stick as the graph in Mann et al 2008 .
What Hagelaars did in the post you refer to, is to review how we’ve arrived at the temperature variations during the Holocene. He then extends it backward to the last ice age. He also extends it forward following the IPCC A1B scenario (2007) which implies a rise in the global mean temperature of 3C. That’s it. There is no “new” data in this graph. I should add that a 3C rise is a moderate, or mitigated, scenario; if Hagelaar had used the “business as usual” 6C rise scenario, the graph would look much more dramatic.
Incidentally, forget the hockey stick. It’s now called a _scythe_.
Starting in March 2013 appeared in Science an article about a temperature reconstruction for the last 11,000 years. The lead author is Shaun Marcott from Oregon State University and the second author Jeremy Shakun, which we know from the previous year and published interesting studies on the relationship between CO2 and temperature during and after the end of the last ice age.
The temperature reconstruction of Marcott is the first to the entire period of the Holocene covers. Obviously not perfect and the coming years will probably details on what changed. A normal part of the scientific process.
Is the study of Marcott be so surprising?
Actually, the famous picture of the temperature variations during the Holocene of Global Warming Art, which often arises on the Internet, is actually a similar picture. You could say that Marcott the average thick black line of the plate has scientifically established. See Figure 2.
The temperature reconstruction ends mid century, therefore, in the graphs of their study the rapid temperature rise after 1850 is clearly visible. And what do you find? Again something that looks like a hockey stick as the graph in Mann et al 2008.
Patterns in temperature reconstructions on hockey sticks appear on climate skeptic websites fervently contested and for the reconstruction Marcott is no different. The number of posts on WUWT on this study, for example, no longer keeping and statistical wonderboy McIntyre blogs also merrily. The viewer would otherwise just once thought that humans strongly influencing the climate, and of course that is not exactly desirable.
The study of Marcott is the proof that the earth in historical perspective quickly is warming. The study is called the Holocene, the geological period of 11,700 years ago until now. The figure of Marcott be deduced that the earth’s temperature after the last ice age has risen to about 7000 years ago, followed by a slow decline observed. The cause of the gradual cooling in recent millennia is a change in the distribution of solar radiation on the earth and the seasons, known Milankovic cycles, which are responsible for the initiation and termination of ice ages. See the explanation on climate portal
After 1850, the influence of man visible in Marcott’s figure, an unprecedented increase in speed of the temperature over 100 years. The average temperature of the last decade has been higher than the temperatures for 72% of the last 11,000 years:
Our results indicate that global mean temperature for the decade 2000–2009 has not yet exceeded the warmest temperatures of the early Holocene (5000 to 10,000 yr B.P.). These temperatures are, however, warmer than 82% of the Holocene distribution as represented by the Standard5×5 stack, or 72% after making plausible corrections for inherent smoothing of the high frequencies in the stack.
Eras have a beginning and an end. You could figure out Marcott’s can deduce that, as regards the climate 150 years ago, a new era has begun. A clear break of the trend over the 11,000 years before. The late Holocene was reached in 1850 and the Anthropocene has started, the era in which man asserts its influence on climate. This leads to a major disbelief in certain parts of the population that was provided at the start of the Anthropocene by Charles Dickens in 1859:
It was the best of times, it was the worst of times,
It was the age of wisdom, it was the age of foolishness,
It was the epoch of belief, it was the period of disbelief
That man is a world to create a climate that human civilization has never known, is clearly visible in Figure 3. If human greenhouse gas emissions continue as at present, the temperature go up. According to the 2007 IPCC A1B scenario in 2100, we are probably somewhere +3.0 degrees above the average for 1961-1990. The expected jump in the temperature of 1850 to 2100 is of the same order of magnitude as that of the end of the last glacial to the Holocene, as is apparent from the data of Shakun-2012 can be derived. See Figure 3.
Even Marcott et al focuses on the projections of climate models of the IPCC2007. They say the following about it:
Climate models project that temperatures are likely to exceed the full distribution of Holocene warmth by 2100 for all versions of the temperature stack, regardless of the greenhouse gas emission scenario considered (excluding the year 2000 constant composition scenario, which has already been exceeded). By 2100, global average temperatures will probably be 5 to 12 standard deviations above the Holocene temperature mean for the A1B scenario based on our Standard5×5 plus high-frequency addition stack.
Unprecedented therefore, as many as 5 to 12 standard deviations above the mean of the temperatures in the Holocene. Welcome to the Anthropocene!
A famous SF series of long ago always began with:
“To boldly go where no man has gone before”
Indeed, we are entering a new era boldly where no man has been. Whether our descendants will be so delighted, I doubt.
grateful I am that you this did
If you are going to push back the start of the Anthropocene William F Ruddiman is worth a look. He has been on this hobby horse for a few years now and is slowly becoming more and more accepted. His is the best explanation of the extended period of the Holocene, because when you look at the Milankovitch Cycles we should be much colder by now.
Prof Ruddiman (Professor Emetitus) is a paleoclimatologist at the University of Virginia.
The impact on climate from 200 years of industrial development is an everyday fact of life, but did humankind’s active involvement in climate change really begin with the industrial revolution, as commonly believed? William Ruddiman’s provocative new book argues that humans have actually been changing the climate for some 8,000 years–as a result of the earlier discovery of agriculture.
The “Ruddiman Hypothesis” will spark intense debate. We learn that the impact of farming on greenhouse-gas levels, thousands of years before the industrial revolution, kept our planet notably warmer than if natural climate cycles had prevailed–quite possibly forestalling a new ice age.
Plows, Plagues, and Petroleum is the first book to trace the full historical sweep of human interaction with Earth’s climate. Ruddiman takes us through three broad stages of human history: when nature was in control; when humans began to take control, discovering agriculture and affecting climate through carbon dioxide and methane emissions; and, finally, the more recent human impact on climate change. Along the way he raises the fascinating possibility that plagues, by depleting human populations, also affected reforestation and thus climate–as suggested by dips in greenhouse gases when major pandemics have occurred. The book concludes by looking to the future and critiquing the impact of special interest money on the global warming debate.
Eminently readable and far-reaching in argument, Plows, Plagues, and Petroleum shows us that even as civilization developed, we were already changing the climate in which we lived.
Review:
“The activities of Stone Age farmers may have altered Earth’s climate. This is the exciting but controversial theory conveyed by palaeoclimatologist William Ruddiman in his well-written book Plows, Plagues and Petroleum. . . . [A]n excellent book summarizing and placing in context the age-old influence of humans on atmospheric composition, climate and global warming.”–Nature
“If you’re not familiar with Ruddiman’s hypothesis, you should be. . . . At a time when some scientist seem to fear that open criticism will give the public the impression that we disagree about the facts on climate change–that it is real, caused in part by humans, and increasingly unavoidable–it is good to read of Ruddiman’s faith in the scientific method and his willingness to let the process unfold as it should. . . . Plows, Plagues and Petroleum is excellent reading for scientist and nonscientist alike.”–James White, Science
“What William Ruddiman has done in Plows, Plagues and Petroleum, an attractive, well-written new book aimed at a popular audience, is to explore the geochemical and climatological implications of worldwide deforestation over the past several thousand years. . . . Ruddiman’s argument makes it clear that there is no ‘natural’ baseline of climate in the late Holocene from which to reckon the human impact of the past two centuries.”–Wolfgang H. Berger, American Scientist
“William Ruddiman’s provocative but plausible conclusion is that the economic behavior of humans began to profoundly influence global climate roughly 8000 years ago. . . . Ruddiman’s book has already begun to spark an important debate–a debate which economic historians should be eager to follow and join.”–Robert Whaples, EH.net
“This well-written book does a great job of summarizing complex topics through simple calculations and examples, and provides the right balance of cultural background and scientific data.”–Matthew S. Lachniet, Geotimes
Personally I would disagree that it had a major impact. Major to me would be able to override the Milankovitch Cycles. Agriculture and land use would be minimal at best, and I see no Paleo Evidence to support it. But I am open to it if it exists. The book is a good read: “Plows, Plagues, and Petroleum”
PPP was a dandy book, but most of the research was 10 years old and a great deal has happened since then. See Special Issue of The Holocene or Bill’s recent Feb 2013 paper The Anthropocene.
For a free article see Dan Vergano’s in USA Today, ,a href=”http://www.usatoday.com/story/tech/columnist/vergano/2013/03/02/anthropocene-climate-farming/1955041/”>Climate change dates back to dawn of first farmers.
A great deal has been learned about the archaeology of rice paddies, and much evidence has accumulated about early farming practices, once researchers starting looking at them closer as well as other data on deforestration/reforestration.
It turns out that previous estimates of earlier land-use were low, way low.
Bill has a new book on the way for next Fall: Earth Transformed.
Yes but,….
The Holocene
http://hol.sagepub.com/content/21/5/865.abstract
“Two lines of evidence suggest that natural explanations for the CH4 increase are falsified: (1) the absence of any sustained methane increase early in seven interglaciations prior to the Holocene; and (2) weakening emissions during the last 5000 years from the two largest global sources of CH4 – north tropical and boreal wetlands. Consistent with this interpretation, a new synthesis of archeological data from southern Asia reported in this issue indicates an exponential increase in CH4 emissions from expanding rice irrigation during the last 5000 years. Neither the anthropogenic nor the natural explanations for the CO2 increase can at this point be falsified”
So I am open
It is well worth reading the whole article, including the conclusions, which start:
“Science moves forward in part by falsification of competing hypotheses (Popper, 2002, based on work originally published in the 1930s and 1950s). Convincing falsification requires a very high standard of ‘disproof’ that can survive subsequent challenges….”
and end (after showing refutations for 3 hypotheses claiming to refute the anthropogenic hypothesis):
“Two natural explanations for the CO2 increase – delayed ocean carbonate compensation and coral reef construction – also remain viable, but both hypotheses face the problem that six of seven previous interglaciations fail to show any CO2 increase. These prevalent mismatches suggest that the late-Holocene CO2 increase is anomalous. The one interglaciation (stage 15) that shows a (small) CO2 increase also has an anomalous benthic d18O trend that continued to decrease throughout the entire early-interglacial interval, instead of leveling out or beginning to increase as it did in the other interglaciations. This anomalous d18O trend suggests a no-analog situation early in stage 15 in which ongoing ice melting played a role in driving the CO2 increase. All six other interglaciations fail to support natural explanations for the CO2 increase.”
Ruddiman and co set a very high bar for claiming falsification of natural cause for the CO2 increase. He is quite conservative on such things, and looks very carefully at evidence for others. More careful examination of stage 15 showed it was quite odd, and rather unlike our interglacial. Occam’s Razor tells me that his explanation (anthropogenic CO2) is almost certainly correct, in the sense that the various error bars are leaving less and less room for a natural increase,
But, again: keep an eye out for the book, where all this is discussed at much more length, including some nice discussion of hypotheses, theories, falsification, etc.
This was written in 2010, and more work has happened since then.
An English translation of Jos Hagelaars’ Dutch post is in the making.
My understanding is that the ice age was 6-8C cooler than today, not just 3C.
eg. here: http://www.geocraft.com/WVFossils/last_400k_yrs.html
Perhaps that’s a regional effect for Antartica. More enlightenment welcome.
I wouldn’t use that site as a reference for anything in particular.
paleo folks weigh in, but I think 3 to 5 C is the range globally – antarctica would most likely be a little more extreme – and ice core temps are not to be extended globally except (broadly, sometimes, on the whole) as general indicators of trend.
No endorsement of the site intended on my part, I just googled for the graph.
Damn, pressed reply too fast…
Same general graph is here: http://www.southwestclimatechange.org/figures/temperature_CO2_concentrations for example.
Dansgaard-Oeschger cycles, or D-O cycles. the shifts from cold stadials to the warm interstadial intervals occurred in a matter of decades, with air temperatures over Greenland rapidly warming 8 to 15°C (Huber et al. 2006). So yes. Note the word Global and the word Antarctica
See http://www.nature.com/nature/journal/v484/n7392/full/nature10915.html#/f3
Thanks, I’m not sure I understand how this affects the temperature shift reported. Perhaps you are saying that ice cap zones swing more than other places on the Earth?
And unfortunately I can’t make out the detail on the previews for the graphs in that article: can you tell me a bit about them? thanks in advance.
There is no evidence for Dansgaard-Oeschger cycles during interglacials.
The D-O cycles (or the ‘bipolar see-saw’) are hypothesized to cause the interstadials during glacial epochs, and they may be related to the way in which the climate goes from a glacial to an interglacial state – a ‘resonance’ or eigenstate of the climate system, which may be triggered by the Milankovic-cycles.
There is *some* evidence for ‘Bond events’ during interglacials: swings with a much lesser amplitude than the D-O cycles:
http://en.wikipedia.org/wiki/Bond_event
However, as you can see in the Marcott-Shakun reconstruction, it is somewhat debatable how influential these Bond Events actually are if you’re looking at *global* temperatures.
Bond events are mainly visible in fluctuations in ice-rafted debris and maybe in droughts.
1) I suspect there will be plenty of refinements, arguments etc over details in this sort of reconstruction, i.e. ,science as usual.
2) But most of the silly arguments derive from a simple goal of some people:
under no circumstances, ever, can it be admitted that the blade of the {hockey stick, or whatever the new one gets called} is human-made. Never.
Any study that supports it being human-created must be discredited, or its authors discredited.
3) See comments at Stoat and later one that includes gremlins and leprechauns.
It’s not just that D-O events don’t seem to happen in interglacials, but we would notice if one were happening. I’m not so sure about events, but generally, if one thinks one of these is causing the current warming:
a) State changes in ocean circulation rearrange heat, at least in short-term. One needs gremlins to explain how that causes all the other well-measured changes, such as increase in OHC.
b) One still needs the leprechauns to nullify the well-established effects of GH gases … and that is often the harder one. People HAVE to make the Greenhouse Effect suddenly stop working.
The nature link was not right it should have been (you cannot edit post here) http://www.nature.com/scitable/knowledge/library/abrupt-climate-change-during-the-last-ice-24288097
Which was a substitute for the link to Huber et al. 2006 (paywall) which I was quoting but the above had the quote in it.
If you are arguing about the word cycles as opposed to the word events then it is more semantics and old conventions for substituting one for the other.
If you are arguing that I said O-D occurred in the glacial – interglacial I did not.
Dansgaard–Oeschger event/Cycles also Heinrich events are seen in the GISP and GISPII ice cores.
D-O, H are freshwater incursion forcing of the AMOC during the asymmetric hemisphere warming/ de glaciations. During the last glacial – interglacial you have Oldest Dryas then Bølling–Allerød to Younger Dryas here to you had the freshwater incursion forcing of the AMOC.
The glacial – interglacial started off as a 41 kyr cycle (mid-Pleistocene) because glacial rebound is slower than the cycle 41 kyr causing larger ice volume over time. This increased freshwater incursion forcing of the AMOC and longer de-glaciations caused the O-D (FWIF of AMOC) to stop the interglacial but creating what we are now call interstadial. Now the 100 kyr orbital forcing has the momentum to go into interglacial but the 41 kyr doesn’t .
The main point of my post is that Regional is not Global (temps) by comparing O-D NH with V cores in the SH.
Our discussion is beyond the scope of the topic if you are arguing over general over very specific.
@John Mashey March 20, 2013 at 5:14 am
I agree with all your points, but nr. 2 is particularly salient.
As an outside observer it is amazing to see how any kind of ‘hockeystick’ immediately causes the gravest symptoms in climate denialists. There is something very deep and very ‘gestalt’ about a simple image that will drive home human influence in one look.
It does not need words, it is immediately obvious. Any kind of handwaving attempt to suggest it is ‘coincidence’ fails – because of the smooth gentle slope for the past 11,300 years (or 1500 years with Mann).
Any alternative explanation will necessarily involve (at least) gremlins and leprechauns. They have to be really well coordinated too, both in timing and magnitude. 🙂
All of this is quite interesting material for the paleo-psychologists of the future. I guess they will not have much trouble to elucidate it.
Thanks,
B.
First off you need to understand proxies and methods in determining climate. Best place to start is here:
http://www.nap.edu/catalog.php?record_id=11676
http://www.physics.ohio-state.edu/~wilkins/energy/Companion/E16.3.pdf.xpdf
To replace my previous link use
http://www.realclimate.org/index.php/archives/2012/04/unlocking-the-secrets-to-ending-an-ice-age/
For the most part the greatest temperature variation is from about +65N to 45N in glacial-interglacial (ice to land changes).
There are problems understanding (you) that they are Signal-to-noise ratio, time averages, sampling, and Asynchrony of proxies and there location etc. This is something that cannot be explained is a single post.
For example you used the Vostok ice core and saw about 5C by measuring the ratio of oxygen-18 to oxygen-16 (expressed as a funny looking broken 8 with small 18 superscript followed by the capital O for oxygen)
At the same location using deuterium-temperature borehole temperature profiles, Borehole temperature measurements at Vostok suggest a temperature change of up to 15 °C surface temperature.
(both are right) it like looking at New York temperatures you have a decadal, seasonal average, monthly, daily, Max and Mins i.e. ranges and so on. You have to know what you are looking at to answer the question what is the temperatures of New York?
Borehole link: http://onlinelibrary.wiley.com/doi/10.1029/97JD02253/abstract
The key is a real understanding of proxies. The simplest explanation of the Global temperatures of the last 20,000 years is to look at the combination of the blue green graph above.
So yes regional changes are not reflective of global changes (temperatures ).
New Alert: Michael E Mann doesn’t know the diff between instrumental temps & proxy reconstructns. http://wattsupwiththat.com/2013/03/18/monday-mirthiness-watch-the-genesis-and-retraction-of-of-a-smear/ … …
distinction without a difference. We know the instrumental (i.e. REAL) temps have gone up. We know that Mann’s work has been replicated multiple times using the same and differing proxies and computer protocols. We know enough about the proxy record, ice cores etc, to know the new graph is solid. Watts et al remain outliers, if not out and out liars.
A clever turn of phrase there Peter 🙂
Why in the world would the folks in Texas pray for a hurricane?
Here’s why….
http://blog.chron.com/climateabyss/2013/03/the-drought-still/
The English translation of Jos Hagelaars’ post, featuring this graph, is now up:
http://ourchangingclimate.wordpress.com/2013/03/19/the-two-epochs-of-marcott/
Bart