Sentences with phrase «in hockey stick reconstructions»

Not exact matches

A graph of the warming trend largely replicates the so - called «hockey stick,» a previous reconstruction that showed relatively stable temperatures suddenly spiking upward in recent history.

Michael Mann, a climate researcher at Pennsylvania State University in State College, is perhaps best known for his work on the «hockey stick» reconstruction of past climate.

McIntyre and his collaborator Ross McKitrick made it their mission to get rid of anything resembling a hockey stick in the MBH98 (and any other) reconstruction of past temperature.

Perhaps you'll join Montford in complaining that hockey - stick shaped proxies dominate reconstructions because they correlate well with temperature.

I was somewhat involuntarily thrust into the center of the public debate over climate change at this very time, when the «Hockey Stick» temperature reconstruction I co-authored, depicting the unprecedented nature of modern warming in at least the past millennium, developed into an icon in the debate over human - caused climate change [particularly when it was featured in the Summary for Policy Makers (SPM) of the Third Assessment Report of the IPCC in 2001].

Steve McIntyre: In respect to the published article, Mann et al 2008, it is my view that the published graphics in the original article and SI, including amendments in 2008, did not include a reconstruction showing a hockey stick that did not involve either strip bark bristlecones or contaminated Tiljander sedimentIn respect to the published article, Mann et al 2008, it is my view that the published graphics in the original article and SI, including amendments in 2008, did not include a reconstruction showing a hockey stick that did not involve either strip bark bristlecones or contaminated Tiljander sedimentin the original article and SI, including amendments in 2008, did not include a reconstruction showing a hockey stick that did not involve either strip bark bristlecones or contaminated Tiljander sedimentin 2008, did not include a reconstruction showing a hockey stick that did not involve either strip bark bristlecones or contaminated Tiljander sediments.

Start the reconstruction in 1404 if you want — hockey stick.

It just so happens that all of the reconstructions that pass these tests (though with skill that decreases in back in time) show hockey stick like features.

I still haven't heard a comment about this «hockey» stick from your part, I believe the reconstruction graph is robust by current all time high temperatures extending back in time since about 1998.

The «hockey stick» reconstruction of temperatures of the past millennium has attracted much attention — partly as it was high - lighted in the 2001 IPCC report as one of the important new results since the previous IPCC report of 1995, and partly as it has become the focus of a number of challenges.

In fact, this conclusion is from the 1995 IPCC report, and thus predates the existence of quantitative proxy reconstructions like the «hockey stick».

In mid-20th Century, medieval temperatures are exceeded in all the reconstructions, hence recent (last 10 - 15 years, say) temperatures appear to be unprecedented for at least a millennium (that even holds for the alternative histories presented by the «hockey stick» criticsIn mid-20th Century, medieval temperatures are exceeded in all the reconstructions, hence recent (last 10 - 15 years, say) temperatures appear to be unprecedented for at least a millennium (that even holds for the alternative histories presented by the «hockey stick» criticsin all the reconstructions, hence recent (last 10 - 15 years, say) temperatures appear to be unprecedented for at least a millennium (that even holds for the alternative histories presented by the «hockey stick» critics).

Well, the work that ultimately led to the so - called Hockey Stick — this reconstruction that demonstrates recent warming to be unprecedented in a long time frame — arose from an effort that really had nothing to do with climate change per se.

And, just as the original Mann et al «hockey stick» was followed by additional work leading to the «spaghetti diagram» of the IPCC in 2007 showing numerous similar reconstructions, with a robust common signal, we can expect that this new paper will for now serve as the standard, but will stimulate additional studies that motivate even stronger conclusions.

If (1) you have a few hockey stick shaped series in a smallish data set which otherwise is cancelling noise, and (2) then re-scale your average to a temperature scale in the calibration period, you can get hockey stick shaped «reconstructions».

That is the Tasmania and Southern South american reconstructions with GISS temp for that latitude, You have a little hockey stick action but look at the average, in estimate Wm - 2 for that chart.

These other reconstructions do tend to show some more variability than MBH98, ie the handle of the hockey stick is not as straight, but they * all * support the general conclusions that the IPCC TAR came to in 2001: the late 20th century warming is anamolous in the last one or two thousand years and the 1990's are very likely warmer than any other time in the last one or two thousand years.»

I beleive it is likely that the Hockey Stick shows less variability than there actually was, other reconstructions seem to show this, but the major findings were the most important (ie how the late 20th century fits in).

One thought that occurred to me while reading this entry is how critical evaluation of millennial reconstructions in general, and criticisms of the hockey stick specifically, are often attributed to specific events or dates that represented a watershed moment.

In our understanding, McIntyre has raised two objections to the hockey - stick reconstruction; one was the statistical problem just mentioned, the other the selective selection of proxy data (the bristlecone question).

In October 2004 we were lucky to publish in Science our critique of the «hockey - stick» reconstruction of the temperature of the last 1000 yearIn October 2004 we were lucky to publish in Science our critique of the «hockey - stick» reconstruction of the temperature of the last 1000 yearin Science our critique of the «hockey - stick» reconstruction of the temperature of the last 1000 years.

At the EGU General Assembly a few weeks ago there were no less than three papers from groups in Copenhagen and Bern assessing critically the merits of methods used to reconstruct historical climate variable from proxies; Bürger's papers in 2005; Moberg's paper in Nature in 2005; various papers on borehole temperature; The National Academy of Science Report from 2006 — al of which have helped to clarify that the hockey - stick methodologies lead indeed to questionable historical reconstructions.

In fact, Marohasy points out that a lack of rising temperatures for recent decades is so common in paleoclimate reconstructions that tendentious climate scientists have necessarily added heavily adjusted, hockey - stick - shaped instrumental records (e.g., from NASA GISS, HadCRUT) on to the end of the trend so as to maintain the visualization of an ongoing dangerous warminIn fact, Marohasy points out that a lack of rising temperatures for recent decades is so common in paleoclimate reconstructions that tendentious climate scientists have necessarily added heavily adjusted, hockey - stick - shaped instrumental records (e.g., from NASA GISS, HadCRUT) on to the end of the trend so as to maintain the visualization of an ongoing dangerous warminin paleoclimate reconstructions that tendentious climate scientists have necessarily added heavily adjusted, hockey - stick - shaped instrumental records (e.g., from NASA GISS, HadCRUT) on to the end of the trend so as to maintain the visualization of an ongoing dangerous warming.

In that paper, we discussed all 19 of the proxy - based global temperature reconstructions of the last millennium, including the Mann «hockey stick».

Role: McKitrick was among the first to take a swipe at the famed «hockey - stick graph,» a reconstruction of temperature in the Northern Hemisphere for the past 1,000 years that has been featured prominently by the Intergovernmental Panel on Climate Change (IPCC), and in Al Gore's movie An Inconvenient Truth.

Of course we do nt want to use any tree ring series that does nt show a hockey stick in the instrumental period for temperature reconstructions, because they do nt exhibit increased growth with increased temperature.

I suppose someone has already mentioned this, but just in case: Even if you allow the BPs, foxtails and other questionable series to be included in the reconstructions, the fact that they ALONE impart a hockey stick curve to otherwise relatively trendless data PROVES that the reconstructions do not represent the NH, let alone the global trend.

Indeed, now that Mann's utterly fallacious hockey stick reconstruction has been re-reconstructed with the LIA and MWP restored, it isn't even remarkable in the last thousand years!

He (McIntyre) was able to demonstrate that the way they had extracted the temperature signal from the tree ring records was biased so as to choose hockey - stick shaped graphs in preference to other shapes... He also showed that the appearance of the graph was due solely to the use of an estimate of historic temperatures based on tree rings from bristlecone pines, a species that was known to be problematic for this kind of reconstruction.

Climategate had a profound affect in that it made clear the cabal at the centre of the hockey stick and temperature reconstructions were not to be trusted.

The biggest problem with what appears here is in the handling of the greater variability found in some reconstructions, and the whole discussion of the «hockey stick».

lolwot — people with an agricultural background point out that northern latitude areas that can not grow certain temperature sensitive crops today, whereas in past years, such as the MWP, the same crops could be grown in those areas disprove Mann's hockey stick temperature reconstruction.

As related in USA Today, the investigation followed a formal complaint by paleoclimatologist Raymond Bradley, co-author of the seminal (and controversial) 1998 and 1999 «hockey stick» temperature reconstructions.

The REAL issue with regard to «the hockey stick» as well as far too much of what is presented as «climate science» is in the opinion - centric attention to «temperature reconstructions», erroneous in their «fabricated production» with included methodology to produce «a temperature proxy» that is NOT relating Kinetic Energy representative OF the «temperature» of those materials present.

Mr. Watts, while you are presenting this new study by Melvin et al. as something that provides results which allegedly refute Mann's hockey stick you do not tell your audience here that the temperature reconstruction shown in the graph, explicitly mentioned by you here, in the Melvin et al paper is done only for a region of Northern Scandinavia, unlike the temperature reconstruction in Mann et al., (1999), doi: 10.1029 / 1999GL900070, which was a reconstruction of the Northern Hemispheric temperature.

With this new, and pretty much entirely arbitrary hurdle in place, Wahl and Amman were able to reject several of the runs which stood between the hockey stick and what they saw as its rightful place as the gold standard for climate reconstructions.

The Hockey stick in this paper doesn't even preclude the possibility of a Medieval Warm Period with about equal temperatures as in the 20th century, since the 20th century average temperature still lies within the upper half of the error band of Mann's Hockey Stick in the part of the reconstruction that covers the Medieval tstick in this paper doesn't even preclude the possibility of a Medieval Warm Period with about equal temperatures as in the 20th century, since the 20th century average temperature still lies within the upper half of the error band of Mann's Hockey Stick in the part of the reconstruction that covers the Medieval tStick in the part of the reconstruction that covers the Medieval times.

Campaigners have highlighted temperature reconstructions like the «hockey stick» graph because they are easy for people to understand, but in scientific terms they are not of great significance.

Their two main results are a confirmation that current global surface temperatures are hotter than at any time in the past 1,400 years (the general «hockey stick» shape, as shown in Figure 1), and that while the Medieval Warm Period (MWP) and Little Ice Age (LIA) are clearly visible events in their reconstruction, they were not globally synchronized events.

In the text: «The «hockey stick» reconstruction of Mann et al. (1999) has been the subject of several critical studies.

The hockey stick shows up in a number of different proxy records, as shown in: «A global multiproxy database for temperature reconstructions of the Common Era»

The latest massive effort in paleoclimatology is the PAGES 2k project which has produced a global temperature reconstruction for the past two millennia - check out my article on it here: http://thinkprogress.org/climate/2013/07/08/2261531/most-comprehensive-paleoclimate-reconstruction-confirms-hockey-stick/ Their results look identical to the original «hockey stick» reconstruction of 1999.

A year ago, I first identified scholarship issues in the 2006 Wegman report, the contrarian touchstone commissioned by Republican congressman Joe Barton as part of his concerted campaign to discredit the «hockey stick» temperature reconstruction and the scientists behind it, especially Michael Mann.

The authors of the original «hockey stick» reconstruction and their work are extremely highly regarded in the scientific community, as seen from the fact that they won important awards from the world's two largest geoscience organisations, the American Geophysical Union and the European Geosciences Union.

Or check out the carbon budget here: http://www.globalcarbonproject.org/carbonbudget/index.htm (2) What exactly is wrong with the «hockey stick» climate reconstruction in your opinion?

The irony here is that the behavior revealed in the e-mails and computer source code was aimed specifically at protecting the Hockey Team's various hockey stick reconstructions, and those graphs are barely even peripheral to climate scHockey Team's various hockey stick reconstructions, and those graphs are barely even peripheral to climate schockey stick reconstructions, and those graphs are barely even peripheral to climate science.

First, warming precedes CO2 rises in the temp reconstructions over geological time; second, failure of the Hockey Stick to support «unprecedented recent warming»; third, the failure to find the model predicted (so - called) «hot spot.»

In particular the paleo proxy reconstructions represent the severe perturbations of the various periods of the Little Ice age as merely shallow downwards blips, whilst the astonishing recovery around 1690 featuring the largest hockey stick in the record is a corresponding shallow upwards blIn particular the paleo proxy reconstructions represent the severe perturbations of the various periods of the Little Ice age as merely shallow downwards blips, whilst the astonishing recovery around 1690 featuring the largest hockey stick in the record is a corresponding shallow upwards blin the record is a corresponding shallow upwards blip

* As paleoclimate reconstructions are measured against global instrumental temperature records commencing 1880 they do not find any» hockey stick» effects seen in older temperature records

There has been renewed interest in the Wegman Report, which purported to critique the work of paleoclimatolgists Michael Mann, Raymond Bradley and Malcolm Hughes and their controversial «hockey stick» millennial temperature reconstruction.