Category Archives: Medieval

Medieval #6: Whitewing Mt, California

Miller et al. [2004] studied fossil evidence of forest levels in 9 locations in the western U.S. over the past 3500 years, including Whitewing Mountain and San Joaquin Ridge, Inyo Craters Chain in the eastern Sierra Nevadas, near the bristlecones of the White Mountains (about which I’m going to post an interesting graphic on their […]

Polar Urals: Shiyatov’s Finnish Academy Article

I’ve written on a number of occasions on Briffa’s Polar Urals reconstruction, which is used in nearly every multiproxy reconstruction, no doubt because of its uniquely cold MWP. It’s one of the key series in Crowley and Lowery [2000] and Jones et al [1998]; it’s not as important in MBH98-99 (which is more or less […]

Bristlecone/Foxtail #2: Bighorn Plateau

Here’s a beautiful picture of a foxtail pine from the MWP, illustrating eloquently the change in treelines: Original Caption: A dead trunk above current treeline from a foxtail pine that lived about 1000 years ago near Bighorn Plateau in Sequoia National Park.

Altitude at Briffa’s Polar Urals

The Polar Urals tree ring site is another staple of multiproxy studies, being used in Bradley and Jones [1993], Hughes and Diaz[1994], Overpeck et al. [1997], Jones et al. [1998], MBH98, MBH99, Crowley and Lowery [2000], Esper et al. [2002], Bradley, Hughes and Diaz [2003] and Rutherford et al. [2005] (which recycles MBH98). In fact, […]

Medieval #5: The Sargasso Sea proxy

There are many regional proxies from around the world that do show the existence of a warm period (warmer than today in most places) called the "Medieval Warm Period" or "Medieval Climate Optimum" roughly from 900-1350AD and a "Little Ice Age" roughly from c.1450 to 1850AD. Amongst the strongest evidence of this is a study […]

The MWP and LIA in Kenya and South Africa

In contrast to the claims of the Mann et al "Hockey Stick", practically all proxy records around the world show large scale multi-decadal and century-scale climatic variation. As another example, here are some of the results from a study by Tyson, Holmgren et al (2000,2001) of Lake Naivasha in Kenya and a well documented stalagmite […]

Medieval #4: Bramsfield Basin, Antarctica

Khim et al. [2002] reported that a core from the Eastern Bramsfield Basin, Antarctic Peninsula showed that the LIA and MWP were the strongest of the Late Holocene cold and warm periods.

Medieval #3: Wassuk Range, California

Millar, Constance, Robert Westfall, Diane Delany, John King and Harry Alden, Climate As An Ecosystem Architect; Responses Of High-Elevation Conifers To Past Climate Variability.

Huldén, Lena, 2001. Terra 113, 171-8. Oak barrels and the medieval warm period in Satakunta [Finland] (Finnish) .

Medieval Treelines #1

Larry Huldén of the Finnish Museum of Natural Science sent me a nice note, mentioning: I have met Phil Jones in Helsinki during a Climate meeting. My wife had a paper on mediaeval warm period in Finland in which she showed that oak (Quercus robur) forests occurred some 150 km north of the present time […]