Category Archives: Paleoclimatology

New paper: Arctic temperatures peaked before 1950, declining since

New paper using Oxygen 18 isotope tracking finds the Arctic temperatures peaked before 1950, and have been stable to declining since. Natural variability is cited as the cause. A new paper published in Climate of the Past reconstructs temperatures over … Continue reading

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Posted in Arctic, Paleoclimatology | Tagged , , , , , , , | 43 Comments

Inverse Underwater Hockey Sticks?

From the University of Toronto,  Underwater ‘tree rings’ Calcite crusts of arctic algae record 650 years of sea ice change Almost 650 years of annual change in sea-ice cover can been seen in the calcite crust growth layers of seafloor … Continue reading

Posted in Arctic, Paleoclimatology | Tagged , , | 125 Comments

Climate and Human Civilization over the last 18,000 years

Guest essay by Andy May This document is meant to explain the accompanying poster and expand on the poster’s content. Some references to the images and data shown in the poster are on the poster and others are in the … Continue reading

Posted in Paleoclimatology | Tagged , | 104 Comments

The oldest ice core – Finding a 1.5 million-year record of Earth’s climate

How far into the past can ice-core records go? Scientists have now identified regions in Antarctica they say could store information about Earth’s climate and greenhouse gases extending as far back as 1.5 million years, almost twice as old as … Continue reading

Posted in Antarctic, Paleoclimatology | Tagged , , | 119 Comments

New paper shows Medieval Warm Period was global in scope

Andrew Revkin writes: Michael Mann can’t be happy about this work. Here’s a chat with two authors of an important new Science paper examining 10,000 years of layered fossil plankton in the western Pacific Ocean. The paper finds that several … Continue reading

Posted in Ocean Heat Content, Oceans, Paleoclimatology | Tagged , , , , , , | 123 Comments

New paper suggests the sun’s magnetic fields defines climate over the long term

Story submitted by Cornelis de Jager (past president ICSU;past pres. COSPAR) In a recent publication entitled Terrestrial ground temperature variation in relation to solar magnetic variability, including the present Schwabe cycle, Cornelis (Kees) de Jager and Hans Nieuwenhuijzen, from the … Continue reading

Posted in Paleoclimatology, Solar | Tagged , , | 144 Comments

The big stink 93.9 million years ago – blame CO2

From the University of California – Riverside , and the department of sulfurous odors, comes this “it must be carbon dioxide” moment: “Also associated with this event are high levels of carbon dioxide in the atmosphere, which are linked to … Continue reading

Posted in Paleoclimatology | Tagged | 187 Comments

Claim: Last 100 years may be warmest in 120,000 years in the Arctic, but not so fast (UPDATED)

From the University of Colorado at Boulder, comes this study about radiocarbon dating some dead moss clumps exposed from under ice/snow at 4 locations on Baffin Island that somehow proves “unprecedented” warmth for the entire Arctic for the last 120,000 … Continue reading

Posted in Arctic, Paleoclimatology | Tagged , , , | 258 Comments

Paleoscientist: Mann’s recent work was a ‘crock of xxxx’

From the soon to be a Climate Crock of the Week department, Barry Woods writes to me in an email: One of the insights in the climategate emails was perhaps how poisonous Michael Mann’s involvement was, for the niche area … Continue reading

Posted in Climate ugliness, Michael E. Mann, Paleoclimatology | Tagged , , , | 146 Comments

We Must Get Rid of the Carboniferous Warm Period

Guest essay by Phillip Mulholland Late Carboniferous to Early Permian time (315 mya — 270 mya) is the only time period in the last 600 million years when both atmospheric CO2 and temperatures were as low as they are today … Continue reading

Posted in Paleoclimatology | 164 Comments

Study: The Late Cretaceous Period was likely ice-free

From the University of Missouri-Columbia COLUMBIA, Mo. – For years, scientists have thought that a continental ice sheet formed during the Late Cretaceous Period more than 90 million years ago when the climate was much warmer than it is today. … Continue reading

Posted in Paleoclimatology, Sea ice | Tagged , , , , , , , | 118 Comments

Retro 3D climate model applied to faint young sun paradox

From the AGU weekly highlights: Evaluating solutions to the faint young Sun problem During the Archean eon, between about 3.8 billion years ago and 2.5 billion years ago, the Sun was about 20 to 25 percent fainter than it is … Continue reading

Posted in Carbon dioxide, Paleoclimatology, Solar | Tagged , , , , , , , , | 96 Comments

More settled science: Climate change/warming speeds up tree life cycles instead of causing migration

From Duke University and the “I was sure those tree rings were linear indicators” department, comes this news: Climate Change May Speed Up Forests’ Life Cycles DURHAM, N.C. – Many climate studies have predicted that tree species will respond to … Continue reading

Posted in Climate News, Paleoclimatology, Positive effects of CO2 | Tagged , , , | 117 Comments

Historic variations in temperature number Four-The Hockey stick

Guest essay by Tony Brown Section 1 Summary of a previous article; A short while ago I published an article on ‘Noticeable climate change’ during the past 500 years, based on historical observation and instrumental records. To understand the context … Continue reading

Posted in Paleoclimatology, Temperature | Tagged , , , , , , , | 83 Comments

Oh Mann! Paper demonstrates that tree-ring proxy temperature data is ‘seriously compromised’

Michael Mann won’t be happy about this. A new paper now in open review in the journal Climate of the Past suggests that “modern sample bias “has “seriously compromised” tree-ring temperature reconstructions, producing an “artificial positive signal [e.g. 'hockey stick'] … Continue reading

Posted in Paleoclimatology | Tagged , , | 112 Comments

I wonder where the plants were during the Medieval Warm Period?

From the University of Arizona Warming climate pushes plants up the mountain  Comparing plant communities today with a survey taken 50 years ago, University of Arizona-led research provides the first on-the-ground evidence for Southwestern plants being pushed to higher elevations … Continue reading

Posted in Paleoclimatology | Tagged , , , | 85 Comments

Claim: CO2 ended the last ice age

From Oregon State University Study explains early warming of West Antarctica at end of last ice age CORVALLIS, Ore. – West Antarctica began emerging from the last ice age about 22,000 years ago – well before other regions of Antarctica … Continue reading

Posted in Carbon dioxide, Paleoclimatology | Tagged , , | 91 Comments

An illustration that CO2 won’t roast the Earth in a runaway tipping point…

…because the Earth has experienced massive CO2 pulses and  recovered before. From the something you don’t see every day department comes this graph:

Posted in Carbon dioxide, Paleoclimatology | Tagged , , , | 108 Comments

Claim: ‘Recent El Niño behavior is largely beyond natural variability’

From the University of Hawaii at Manoa: El Nino unusually active in the late 20th century Spawning droughts, floods, and other weather disturbances world-wide, the El Niño – Southern Oscillation (ENSO) impacts the daily life of millions of people. During … Continue reading

Posted in ENSO, Paleoclimatology | Tagged , , , , , , | 105 Comments

Hey Ya! (mal) McIntyre was right – CRU Abandons one tree Yamal Superstick

This must be personally satisfying for Steve McIntyre, though I doubt the folks at RealClimate will have the integrity to acknowledge that he was right, and they were wrong. It seems that in the latest publication from CRU’s Keith Briffa, … Continue reading

Posted in Paleoclimatology | Tagged , , , , , , , | 154 Comments

Paper: ‘Summer temperatures were about 10°C warmer than today, even though the concentration of atmospheric CO2 was similar’

From AAAS: From Russia with Lovely Data Climate and the atmospheric concentration of CO2 are closely linked. Brigham-Grette et al. (p. 1421, published online 9 May) present data from Lake El’gygytgyn, in northeast Arctic Russia, that shows how climate varied … Continue reading

Posted in Paleoclimatology | Tagged , , , , , , , | 56 Comments

Global cooling as significant as global warming

From Newcastle University Global cooling as significant as global warming A “cold snap” 116 million years ago triggered a similar marine ecosystem crisis to those witnessed in the past as a result of global warming, according to research published today … Continue reading

Posted in Global cooling, Global warming, Paleoclimatology | Tagged , , , , , , , | 64 Comments

The East Anglia Rococo

Steve McIntyre has a new analysis up, one that has a strong headline. Though as he says, “not in so many words”, but more about techniques and exclusions. He writes: Briffa Condemns Mann Reconstructions

Posted in Paleoclimatology | Tagged , , , , , , , | 54 Comments

An interesting issue with ice core data

This guest essay by William Hunt had some serious errors in it, as pointed out by commenters (thank you) and thus has been removed. – Anthony

Posted in Paleoclimatology

Multiple, Intense, Abrupt Late Pleistocene Warming And Cooling: Implications For Understanding The Cause Of Global Climate Change

Guest essay by Dr. Don J. Easterbrook Dept. of Geology, Western Washington University, Bellingham, WA The results of oxygen isotope measurements from ice cores in the Greenland and Antarctic ice sheets several decades ago stunned the scientific world. Among the … Continue reading

Posted in Paleoclimatology | Tagged , , , , , , , | 89 Comments

Plants that got buried during the Little Ice Age come to life again

From the University of Alberta, this news release is making the rounds, but what many of the alarmists don’t get (Joe Romm for example) is that these plants had to have a warm environment to grow in first, then they … Continue reading

Posted in Paleoclimatology | Tagged , , , , , , , | 59 Comments

Briffa, Yamal, reputational damage, and all that

Keith Briffa has just published a new paper using the Yamal-Urals regional chronology data, something long sought after via FOIA requests. That data was withheld, citing it wasn’t cooked done with yet, and that releasing it would damage the reputation … Continue reading

Posted in Climategate, Paleoclimatology | Tagged , , , , , , , | 91 Comments

Where Lies the Younger Dryas Smoking Gun?

Guest Post by Dan Johnston I have been following the proposed collision theory for the onset of the Younger Dryas for a number of years with considerable interest as it explains so much in a relatively straightforward fashion, if true. … Continue reading

Posted in Paleoclimatology | Tagged , | 86 Comments

Widespread evidence of cosmic impact documented – likely cause of the Younger Dryas cool climate episode

From the University of California – Santa Barbara some paleoclimatology without the need to see hockey sticks. Comprehensive analysis of impact spherules supports theory of cosmic impact 12,800 years ago (Santa Barbara, California) –– About 12,800 years ago when the … Continue reading

Posted in Paleoclimatology | Tagged , , | 73 Comments

New NSF paleo research claiming Arctic was warmer fails to take major ocean circulation changes 3 million years ago into account

I covered this story earlier today, and it was presented much differently in that press release. This press release takes a different tack. IMHO, it looks like a big “ooops” from the National Science Foundation. See what I found after … Continue reading

Posted in Arctic, Paleoclimatology | Tagged , , , , , , , | 49 Comments

The Stokes-Kaufman contamination protocol – a ‘sticky’ wicket

Over at Climate Audit, Steve McIntyre has found yet another unexplainable inclusion of a hockey stick shaped proxy in the PAGES2K paper. What is most interesting about it is that when you look at the proxy plot panel, it reminds … Continue reading

Posted in Land use land cover change, Paleoclimatology, Proxies | Tagged , , , , , , , | 90 Comments

A Quick Comment about the PAGES Continental Temperature Reconstructions

Normally, I don’t bother to discuss paleoclimatological reconstructions. The reason: most try, some through questionable methods, to illustrate that the recent warming is unusual and could only be explained by the increased emissions of manmade greenhouse gases. And that’s the … Continue reading

Posted in Paleoclimatology | 62 Comments

Yet another ‘unprecedented’ hot times tree ring reconstruction

From The Earth Institute at Columbia University comes another tree ring hockey stick. I have to laugh though at the choice of graphic for the press release, which shows a weather event (Euro heat wave) in 2003, rather than showing … Continue reading

Posted in Paleoclimatology | 94 Comments

Gergis made to order IPCC zombie climate science

Steve McIntyre points out how climate science errors return from the dead as zombies: PAGES2K, Gergis and Made-for-IPCC Journal Articles March 15, 2013 was the IPCC deadline for use in AR5 and predictably a wave of articles have been accepted. The … Continue reading

Posted in Gergis et al, Paleoclimatology | 55 Comments

Crowdsourcing the WUWT Paleoclimate Reference Page – Disputed Graphs – Alley (2000)

Image Credit: Photobucket.com – GISP2 – Alley, 2000 By WUWT regular “Just The Facts” In building WUWT Paleoclimate Reference Page during these crowdsourcing threads (1, 2) there have been a number disputes raised about various graphs. During this thread I … Continue reading

Posted in Paleoclimatology, Temperature | Tagged , , , , | 66 Comments