HOLOCENE PALEOCLIMATOLOGY OF THE QUEEN ELIZABETH ISLANDS, CANADIAN HIGH ARCTIC

A wide variety of evidence reflecting, in different ways, the changing climate of the Queen Elizabeth Islands during the Holocene is reviewed. All proxies pertain to summer conditions. Many sources of information provide weak or equivocal paleoclimatic signals, but a general pattern of events can be discerned. Temperatures in the early to mid-Holocene were highest (comparable with, or higher than, temperatures prevailing for much of this century). Although much evidence points to a mid-Holocene thermal maximum, there is also considerable evidence that conditions were warmer in the early Holocene, possibly related to orbitally-induced radiation anomalies. The apparent mid-Holocene thermal maximum may reflect lags in the response of the environment and of some proxies in recording paleoclimatic conditions; more direct indices point to warmest conditions in the early Holocene (before 7500 BP). Temperatures declined from ∼3000 BP, culminating in exceptionally low temperatures from 100-400 BP. This may have been the coldest period of the entire Holocene, resulting in glacier advances to post-glacial maximum positions. The period since 1925 has witnessed a pronounced increase in temperature, leading to negative mass balances on glaciers and ice sheets throughout the archipelago. This period is the warmest for at least 1000 years and perhaps for several thousand years. Modern climate in the Queen Elizabeth Islands may thus be characteristic of the early to mid-Holocene and atypical of conditions which prevailed for much of the last few thousand years. © 1990.