Category Archives: Holocene Optimum

“More and more concerned about our statement”

In a previous post, I reported that Coordinating Lead Author Overpeck wanted to “deal a mortal blow to the misuse of supposed warm period terms and myths in the literature”. The MWP was one such target; the Holocene Optimum was another. Overpeck said that there was “no need to go into details on any but […]

Interview with Fred Michel on Arctic Ice Shelves

Fred Michel, an Arctic specialist from Carleton University, in an interview, discusses Arctic ice shelf break-up.

Ice Island T-3

Looking at the Ward Hunt Ice Shelf, the specialist literature distinguished between “basement” ice that is relatively old and firn ice that is much younger. The “basement ice” period ended with the end of the “first ablation period” which Crary 1960 dated to ~1600 BP – a date which Lyons et al 1973 noted to […]

Ayles Ice Shelf, Ellesmere Island

Late last year and early this year, various news stories reported the demise of the Ayles Ice Shelf, Ellesmere Island. On Dec. 29, 2006, National Geographic reported Giant Ice Shelf Breaks Off in Canadian Arctic and on Jan 4, 2007, CNN reported the story. The catastrophe actually occurred in August 2005, but no one noticed […]

The Team versus Stott et al 2004

The Team (at both realclimate and NOAA) have stated in the strongest possible terms that the Holocene Optimum was restricted to summer in the NH extratropics. Reviewing their positions, realclimate here The [Holocene Optimum] is a somewhat outdated term used to refer to a sub-interval of the Holocene period from 5000-7000 years ago during which […]

Ellesmere Island Driftwood

It turned out that the age of Ellesmere Island ice shelves is estimated by driftwood located on the shore. an age of ~3,000 years is estimated for the Ward Hunt ice shelf (in which a crack recently developed) based on driftwood located onshore. I haven’t seen corresponding information on the Ayles ice shelf (which actually […]

Ellesmere Island Ice Shelves

The break-up of (Ward Hunt and Ayles) ice shelves on the north shore of Ellesmere island gets in the news from time to time (google “Ward Hunt ice shelf”) and has been mentioned by posters here. The issue as framed by Steve Bloom is: However, if [the Ward Hunt Ice Shelf] is ~3000 year old […]

Lorenz et al 2006: “Tropical Cooling”

Despite the protestations of the Team, it seems to be a consensus of other paleoclimatologists that the Holocene Optimum was warmer at high southern latitudes. For now, I’ll take this as read, although it’s well worth canvassing the literature. Some citations are at ukweatherworld. The next line of Team attack on the Holocene Optimum is […]

Holocene Optimum

Since Hansen’s article in September, we’re starting to hear the phrase “warmest in 12000 years”- google “warmest 12000 years” and you’ll see recent coverage. This immediately raises the question of the Holocene Optimum – a period from about 8000 to 5200 BP in which there is undisputed evidence of significant NH warmth.  The Team has […]