Is Current Global Warming Unprecedented?

Another thread on global warming ended with [MENTION=21405]jackdog[/MENTION] questioning my statement that the current rate of global warming is unprecedented in the last 10,000 years.

The page linked to at Biology Cabinet presents several charts in an attempt to show that temperatures in the Holocene were at times warmer than today. The first two charts credit Broecker 2001, "Was the Medieval Warm Period Global?", for temperature fluctuations measuring up to 6 °C when Broecker says no such thing. In fact, Broecker states right up front:

The claim that Medieval Warm Period temperatures were as high as today was also laid to rest by Bradley et al. 2003, "Climate in Medieval Time".

As for the other papers which he lists, I would like to point him to something a little more current:

Marcott et al. 2013, "A Reconstruction of Regional and Global Temperature for the Past 11,300 Years"

Miller et al. 2013, "Unprecedented recent summer warmth in Arctic Canada"


If anyone knows of a source showing that global temperature has changed by more than 1 °C per century any time in the last 10,000 years, I invite them to post it here.

 

but previous warm periods are a phony distraction, no one has ever claimed the earth has not been warmer or cooler before...previous CC events is something denierworld stumbled upon by accident when they discovered the internet, they assume they're absolutely brilliant for their little enlightenment that only they are aware of...what they're are oblivious to is those other CC events were studied to confirm that this CC event is not a natural event but anthropogenic...

by addressing denierworlds "it was warmer before" silliness we dumb down the debate ...

 

Silly!!! Really silly!

 

Marcott admitted the flaws in his reconstruction on real climate

http://www.realclimate.org/index.php/archives/2013/03/response-by-marcott-et-al/comment-page-1

Q: What do paleotemperature reconstructions show about the temperature of the last 100 years?

A: Our global paleotemperature reconstruction includes a so-called “uptick” in temperatures during the 20th-century. However, in the paper we make the point that this particular feature is of shorter duration than the inherent smoothing in our statistical averaging procedure, and that it is based on only a few available paleo-reconstructions of the type we used. Thus, the 20th century portion of our paleotemperature stack is not statistically robust, cannot be considered representative of global temperature changes, and therefore is not the basis of any of our conclusions.

Roger Pileke took out the 20th century part of that data that Marcott admits is not statistically robust and this is what happens. Notice the difference when you are not using the old hockey stick "nature trick"



even Andy Revkin and the NY Times have made corrections and another of the authors of the paper have said they should have not spliced high frequncy data onto smoothed low frequncy data http://dotearth.blogs.nytimes.com/2...mperature-changes/?_php=true&_type=blogs&_r=0

Tamino also looked at the data and methodology, and here is his take on Marcott et al

http://tamino.wordpress.com/2013/03/22/the-tick/



during my first class in Probability and Statistics the professor told us " find out what you client wants to prove then look for a way to get the numbers to prove it" . Every time I see a CAGW "hockey stick " graph I can picture that professors standing on the lectern. Marcott et al is a shining example

 

RE Tamino: Wow! Just Wow. Another Chapter in the Deniers Can't Read Book!
First let me quote Tamino from your link
"The “big picture” is unchanged — temperature changes over the last 10,000 years have been no larger, and much slower, than what we witnessed in the 20th century (as reported by thermometers)."

And once again, JD, you pick a graph you think supports your view but ignore the rest of Tamino's post.
And once again, JD, you ignore the papers that don't support your view.
How about addressing the first 2 papers that contrails lists?

 

how about this we play my paper trumps your paper and my scientist can beat up your scientist for 37 more pages in this thread which would only prove one thing. The science is not settled

 

How about you showing me where I ever stated that the science is settled?

 

is that a triple dog dare lol, I have better things to do than play childish games

 

Alarmist "scientists" conjur up some nonsense in support of their agenda - then say "the debate is over", lol...

That isn't science, that is nonsense.

For something to be scientifically valid, it must survive attempts to falsify it - by definition, and quite properly, that is what "skeptics" do. It is the "skeptics" that are practicing science. The alarmists are practicing agenda driven propaganda.

To make matters worse - even after a study is proven false, the alarmists continue to march forward as if it were true. Absolutely refusing to admit that what they are touting has been falsified, lol...

It's amazing to watch, and disgusting to think that this is what "science" has been degraded to by the radical left... "the ends justifies the means".

It's sad.

 

it's not about science these days , it's about money and politics. A billion here and a billion there adds up to real money

http://www.reuters.com/article/2012/08/31/us-usa-china-reid-solar-idUSBRE87U06D20120831



In 2003, the Nevada Democrat publicly banned relatives from lobbying him or his staff after newspaper reports showed that Nevada industries and institutions routinely turned to Reid's sons or son-in-law for representation.

Now, questions surrounding family ties are flaring again in Nevada around the Senate majority leader. He and his oldest son, Rory, are both involved in an effort by a Chinese energy giant, ENN Energy Group, to build a $5 billion solar farm and panel manufacturing plant in the southern Nevada desert.

Reid has been one of the project's most prominent advocates, helping recruit the company during a 2011 trip to China and applying his political muscle on behalf of the project in Nevada. His son, a lawyer with a prominent Las Vegas firm that is representing ENN, helped it locate a 9,000-acre (3,600-hectare) desert site that it is buying well below appraised value from Clark County, where Rory Reid formerly chaired the county commission.

Craig Holman, a lobbyist for the non-partisan advocacy group Public Citizen, said the senator is dealing with "an iffy ethical landscape" because of the family connections and should recuse himself from the project. "Is this just happening because ... it benefits the Reid family, or did Harry Reid actually believe in this?" Holman said.

The senator has supported numerous clean energy projects in Nevada. Rory Reid cites energy as one of his specialty areas at the law firm.

The two Reids deny discussing the ENN project.

"I have never discussed the project with my father or his staff," said Rory Reid. Kristen Orthman, a spokeswoman for the senator, said he had not discussed the project with his son.

The Langfang, China-based ENN Energy Group hopes to build what would be the largest solar energy complex in America. The site chosen with Rory Reid's guidance is in tiny Laughlin, Nevada, a gambling town of 7,300 along the Colorado River, 90 miles south of Las Vegas.

County officials have said that they were so thrilled to recruit a company to the area, with the prospect of thousands of new local jobs, that they were eager to negotiate.

ENN is headed by Chinese energy tycoon Wang Yusuo, who made a fortune estimated by Forbes at $2.2 billion distributing natural gas in China. Wang escorted Reid and a delegation of nine other U.S. senators on a tour of the company's clean energy operations in Langfang, and Reid featured Wang as a speaker at his 4th annual National Clean Energy Summit in Las Vegas last year.

 

Since the Marcott reconstruction has a stated resolution of about 300 years, one would not expect the last 100 years to be "statistically robust". Fortunately, we don't need reconstructions to know what temperatures were in the last 100 years, so I don't see how this is a problem. Even Tamino agrees that while probably overstated, the uptick doesn't affect the main conclusion of Marcott's paper, that Holocene climate change was nothing like what we're seeing today. From the link you provided:

 

I'm still waiting for someone to point out who all of these rich climate scientists are.

 

you'll be waiting a very loooooong time, it's a conspiracy you know...I'm sure the free masons and elvis and jimmy hoffa also involved....

 

First off thanks for actually participating in a discussion. It is a refreshing change from the behavior of others here

Not just the last 100 years, although most everyone recognizes the flaws if you take low resolution smoothed data then splice high resolution onto the end of it . It also seems as if one of Marcott's proxies was not representative of the Southern Hemisphere. Steve McIntire wrote a nice essay on it at Climate Audit

Contribution of TN05-17 to the Marcott SHX reconstruction.

http://climateaudit.org/2013/04/10/the-impact-of-tn05-17/

Given the overwhelming importance of this proxy, one would like to know a little more about it. The next graphic compares TN05-17 to two other SHX proxies, also MAT proxies but from small lakes in southern New Zealand. The inconsistency of the proxies is evident. The New Zealand paleolimnological proxies have nothing resembling the mid-Holocene “cold period” that characterizes TN05-17. One thing that this graphic shows for sure: the residuals of these proxies from the “true” temperature history as translated to the respective sites do not remotely resemble a low-order AR1 process. To properly model the error distribution, one has to have an error model that permits excursions for millennia – not at all easy to specify.



even a layman can look at TN05-17 and see that it is not representative of the temperatures of the mid Holocene. Michael Mann used the same technique ( cherry picking proxies) to distort the temperature in his famous hockey stick. You can take one outlier and a number of other proxies and smooth the data and you get a hockey stick handle

 

Irrelevant, since the 20th century is well covered in the thermometer record.

Wow! When you remove the 20th century, there is no 20th century warming! That Roger sure is a genius!

What you think your source said and what it really says are two different things. Are you sure you actually read the stuff you cite?

If you were reading Tamino's blog, how is it you missed this posting just a few days later, in which he demonstrated that the current rate of warming is in fact unprecedented in the Holocene, and that any century similar to the 20th in terms of warming would have been as visible in Marcott's data as a harlot at the church picnic.

And Climate Audit isn't?

 

Even if McIntyre is correct, that TN05-17 skews the reconstruction, it still does not address the key point of Marcott 2013. It's not the magnitude of current temperature that is the problem, but rather the rate at which it is changing.

Tamino does a good job addressing the regional differences of Marcott 2013, including the problem of fewer proxies in more recent time periods.

http://tamino.wordpress.com/2013/03/23/regional-marcott/

 

First of all that brings us right back to the problem of using high resolution data for the last 100 years, also why would you expect to see a sudden jump when the resolution of the early and mid Holocene is 300 years, uses and uses outlier data to exaggerate the smoothing? That's a smoke and mirrors apples and oranges paper just like all of Mike Manns which was written and reviewed to make a political point in a losing argument

 

If I'm not mistaken, Tamino did a really good job explaining the up-tick in the article you linked to in Post #4.

http://tamino.wordpress.com/2013/03/22/the-tick/

 

Asked and answered.

 

Selecting only high-resolution proxies from the Marcott dataset (high-resolution meaning 160 year resolution or less), and comparing it to the 160-year thermometer record from BEST, we get these 160-year temperature changes:



Is the current warming rate unprecedented in the last 10,000 years? You betcha.

 

we are just dogs chasing out tails here now. This is nothing but a duel of the papers just like most of the threads on this topic. I am sure we can all find thousands of peer reviewed papers supporting both sides of the argument, so for me at least it has grown tedious and boring

 

Explain to us dumbass "deniers" how climate change has EVER HAPPENED BEFORE since this seems to be, according to you brilliant scientific type people, the original "anthropogenic" event that is causing this NON-phenomenon now. Oh wait a second...we have the word of this guy that it's an original event caused by us filthy, dirty, breathing human beings and our use of the planets assets to escape the middle ages...by which time global cooling and warming had already happened thousands of times over. Explain please. And I won't settle for Gore's inconvenient truth of which he is one of the guiltiest violators on the planet.

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And yet...it doesn't take much common sense at all to figure out the political scam involved in all of this.

 

Utter and total tripe. You have not cited a single peer-reviewed paper on this thread. You have cited nothing but news reports and blogs. I don't even think you know how to cite a paper. And I doubt you have ever read one.

And I'm sure that if you could find thousands of papers to support your positions, you would actually cite one. You haven't, because you can't, because there aren't.

 

There are a lot of natural forcings that can cause climate change. For example:
1. Volcanoes can cause climate change, both short-term and long-term.
2. Small changes in Earth's orbit (called Milankovitch cycles) can trigger climate change.
3. Changes in solar activity can cause climate change.
4. Changes in ocean circulation can cause climate change.

In addition there are many feedback mechanisms that work to make forcings stronger (or weaker). Some of those feedbacks are more or less effective depending on the forcing agent.

With regard to the current warming, every natural forcing agent that has so far been suggested has been falsified. Which is (one of the reasons) we know the current climate change is caused by us.