What was done
Sediment cores were recovered from three mid-Arctic lakes on the Cumberland Peninsula of eastern Baffin Island in the Canadian Arctic. Radiocarbon dating of macrofossils they contained, together with luminescence dating, allowed the authors to isolate and study the portions of the cores pertaining to the last interglacial, which occurred approximately 117,000-130,000 years ago. More specifically, they used pollen spectra derived from the cores to reconstruct the past vegetation and climate of the region during this period.

What was learned
"In each core," to quote the researchers, "last interglacial sediments yielded remarkably high pollen concentrations, and included far greater percentages of shrub (Betula and Alnus) pollen grains than did overlying Holocene [current interglacial] sediments." In fact, they say that "from applications of both correspondence analysis regression and best modern analogue methodologies, we infer July air temperatures of the last interglacial to have been 4 to 5°C warmer than present [our italics] on eastern Baffin Island," which warmth was greater than that of any interval within the Holocene. Giving even more weight to their results, they say their July air temperature reconstruction is "directly comparable to both earlier qualitative estimates (LIGA Members, 1991; Bennike and Bocher, 1994), as well as more recent quantifications from ice core (NGRIP Members, 2004) and pollen (Andreev et al., 2004) analyses."

What it means
If there is anything unusual or unprecedented about current Arctic temperatures, as the world's climate alarmists are fond of claiming when spinning their biosphere-threatening global warming scenarios, it is that they are so much lower than they were during the last interglacial; and if the Arctic behaves anything like the Antarctic in this regard, one can extend this relationship back in time through three more interglacials (Petit et al., 1999; Augustin et al., 2004.). Clearly, therefore, the Arctic was much warmer than it is today throughout several periods of earth's history; and the planet's many current life forms fared just fine during all of them ... else, of course, they wouldn't be here today!

References
Andreev, A.A., Grosse, G., Schirrmeister, L., Kuzmina, S.A., Novenko, F.Y., Bobrov, A.A., Tarasov, P.E., Ilyashuk, B.P., Kuznetsova, T.V., Krbetschek, M., Meyer, H. and Kunitsky, V.V. 2004. Late Saalian and Eemian paleoenvironmental history of the Bol'shoy Lyakhovsky Island (Laptev Sea Region, Arctic Siberia). Boreas 33: 319-348.

Augustin, L., Barbante, C., Barnes, P.R.F., Barnola, J.M., Bigler, M., Castellano, E., Cattani, O., Chappellaz, J., Dahl-Jensen, D., Delmonte, B., Dreyfus, G., Durand, G., Falourd, S., Fischer, H., Fluckiger, J., Hansson, M.E., Huybrechts, P., Jugie, G., Johnsen, S.J., Jouzel, J., Kaufmann, P., Kipfstuhl, J., Lambert, F., Lipenkov, V.Y., Littot, G.C., Longinelli, A., Lorrain, R., Maggi, V., Masson-Delmotte, V., Miller, H., Mulvaney, R., Oerlemans, J., Oerter, H., Orombelli, G., Parrenin, F., Peel, D.A., Petit, J.-R., Raynaud, D., Ritz, C., Ruth, U., Schwander, J., Siegenthaler, U., Souchez, R., Stauffer, B., Steffensen, J.P., Stenni, B., Stocker, T.F., Tabacco, I.E., Udisti, R., van de Wal, R.S.W., van den Broeke, M., Weiss, J., Wilhelms, F., Winther, J.-G., Wolff, E.W. and Zucchelli, M. 2004. Eight glacial cycles from an Antarctic ice core. Nature 429: 623-628.

Bennike, O. and Bocher, J. 1994. Land biotas of the last interglacial/glacial cycle on Jameson Land, East Greenland. Boreas 23: 479-487.

LIGA Members. 1991. Report of the 1st discussion group: the last interglacial in high latitudes of the northern hemisphere: terrestrial and marine evidence. Quaternary International 10-12: 9-28.

NGRIP Members. 2004. High-resolution record of Northern Hemisphere climate extending into the last interglacial period. Nature 431: 147-151.

Petit, J.R., Jouzel, J., Raynaud, D., Barkov, N.I., Barnola, J.-M., Basile, I., Bender, M., Chappellaz, J., Davis, M.., Delaygue, G., Delmotte, M., Kotlyakov, V.M., Legrand, M., Lipenkov, V.Y., Lorius, C., Pepin, L., Ritz, C., Saltzman, E. and Stievenard, M. 1999. Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica. Nature 399: 429-436.