Category Archives: Paleoclimatology

New ice core record shows climate variability in West Antarctica

Similar warming and cooling trends occurred in the mid-nineteenth and eighteenth centuries From AGU highlights: A 308-year ice core record provides new data on climate variability in coastal West Antarctica and shows that a clear warming trend has occurred in … Continue reading

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Posted in Antarctic, Paleoclimatology | Tagged , , , , , , , | 31 Comments

Rapid climate changes in the younger Dryas, but with a 120 year time lag

From GFZ GeoForschungsZentrum Potsdam, Helmholtz Centre Regional climate changes can be very rapid. A German-British team of geoscientists now reports that such a rapid climate change occurred in different regions with a time difference of 120 years. Investigation in the … Continue reading

Posted in Paleoclimatology | Tagged , , , , , , , | 44 Comments

Study: Greenland Ice Sheet was smaller 3000-5000 years ago than today

From the University of Buffalo Clues in the Arctic fossil record suggest that 3-5,000 years ago, the ice sheet was the smallest it has been in the past 10,000 years Summary: Ice sheets are like bulldozers. As they grow, they … Continue reading

Posted in Greenland ice sheet, Paleoclimatology | Tagged , , , , , , , | 83 Comments

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

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