Funder et al argued that driftwood travelled in sea ice across the Arctic Ocean during periods of less sea ice than at present and was deposited on now raised beaches in northern Greenland.
Funder et al 2011 is a useful study, but neither its use of driftwood nor its reconstruction of Holocene sea ice is original. These findings were articulated in substantially similar form in Dyke et al (1997), which was discussed at length in a Climate Audit post in 2007 here and here. Funder et al cite Dyke et al 1997 on multiple occasions and use its information in their analysis, though, needless to say, the press releases make the study sound more original than it really is. I don’t think that this is a defect in the study – studies can add useful data (as this one does) without being particularly “original” in an academic sense.
Here is a re-quotation of the abstract of Dyke et al 1997:
Driftwood appears to be absent in the Beaufort Gyre but abundant in parts of the Transpolar Drift (TPD), which crosses the Arctic Ocean from the Chukchi Sea to the vicinity of northeastern Greenland. Nearly 300 radiocarbon dates on Holocene driftwood from the Canadian Arctic Archipelago reveal two regions with contrasting histories of driftwood incursion: the region accessible to wood brought into Baffin Bay by the West Greenland Current and the rest of the archipelago, which receives wood from the Arctic Ocean. We hypothesize that when the TPD was deflected westward along northern Greenland, wood was delivered widely to the Canadian Arctic Archipelago; when the TPD exited entirely through Fram Strait via the East Greenland Current, little or no wood was delivered to most of the archipelago, but some continued into Baffin Bay via the West Greenland Current. A split TPD delivered wood to both regions. The regional driftwood incursion histories exhibit multiple maxima and minima that can be explained by this hypothesis. The Larix to Picea ratio of wood arriving in the Canadian Arctic Archipelago has also changed through time. This may indicate varying contributions from Russian versus North American sources, which in turn may indicate variable mixing of wood en route. The inferred discharge paths of the TPD were apparently stable for intervals ranging from several millennia to centuries or perhaps only decades. The last major switch broadly correlates with the onset of Neoglaciation.
Similar points are reported in Funder et al 2011. For example:
The changing proportions of larch and spruce therefore indicate changes in the strength of the TPD and BG, which are driven by atmospheric circulation (6 – Dyke et al 1997, 11).
The period ~8.5 to 6 ky B.P. marks the Holocene Thermal Maximum (HTM) in this area. Long continuous beach ridges northward along the coast up to 83°N show that this was the southern limit of permanent sea ice, ~1000 km to the north of its present position (Fig. 1C).
during the HTM [Holocene Thermal Maximum] in north Greenland were 2° to 4°C warmer than now, as elsewhere in this part of the Arctic (17). Driftwood from this period is sparse, and because there was free access to the coast, we can conclude that multiyear sea ice was reduced.
our data suggest more open water than at present until at least 4.5 ky B.P. (Fig. 3). The same pattern is seen on Ellesmere Island, but here permanent land-fast ice began to grow at 5.5 ky B.P., spreading to block most of the coast at 3.5 ky B.P. (5).
And an interesting MWP observation:
A larch-dominated peak at ~1100 to 1400 indicates a strong TPD and a weak BG during the Medieval Warm Period, whereas the woodless periods and the increase in spruce after 1400 show that situations with large BG input became increasingly frequent during the Little Ice Age (LIA), as shown also in the western Arctic Ocean (22).