"Arctic sea ice cover was strongly reduced during most of the early Holocene; there appears even to have been periods of ice free summers in large parts of the central Arctic Ocean (Fig. 2)."
Wikipedia, edited by activists such as William Connolley, falsely claims,
"There is currently no scientific evidence that a seasonally ice-free Arctic Ocean existed anytime in the last 700,000 years, although there were periods when the Arctic was warmer than it is today."
|Periods of low sea ice are shown in dark green. Horizontal axis is thousands of years before the present.|
New insights on Arctic Quaternary climate variability from palaeo-records and numerical modelling
- a Department of Geological Sciences, Stockholm University, 106 91 Stockholm, Sweden
- b Department of Geography, Durham University, Science Site, South Road, Durham DH1 3LE, UK
- c Faculty of Earth Sciences, University of Iceland, Is-101 Reykjavik, Iceland
- d Centre for GeoGenetics, Natural History Museum, University of Copenhagen, Øster Voldgade 5-7, DK-1350 Copenhagen, Denmark
- e Academy of Sciences, Humanities and Literature, Mainz, and Leibniz Institute of Marine Sciences, IFM-GEOMAR, Wischhofstr. 1-3, D-24148 Kiel, Germany
- Accepted 26 August 2010. Available online 2 October 2010.
Terrestrial and marine geological archives in the Arctic contain information on environmental change through Quaternary interglacial–glacial cycles. The Arctic Palaeoclimate and its Extremes (APEX) scientific network aims to better understand the magnitude and frequency of past Arctic climate variability, with focus on the “extreme” versus the “normal” conditions of the climate system. One important motivation for studying the amplitude of past natural environmental changes in the Arctic is to better understand the role of this region in a global perspective and provide base-line conditions against which to explore potential future changes in Arctic climate under scenarios of global warming. In this review we identify several areas that are distinct to the present programme and highlight some recent advances presented in this special issue concerning Arctic palaeo-records and natural variability, including spatial and temporal variability of the Greenland Ice Sheet, Arctic Ocean sediment stratigraphy, past ice shelves and marginal marine ice sheets, and the Cenozoic history of Arctic Ocean sea ice in general and Holocene oscillations in sea ice concentrations in particular. The combined sea ice data suggest that the seasonal Arctic sea ice cover was strongly reduced during most of the early Holocene and there appear to have been periods of ice free summers in the central Arctic Ocean. This has important consequences for our understanding of the recent trend of declining sea ice, and calls for further research on causal links between Arctic climate and sea ice
full paper available here
full paper available here