A greenhouse Arctic – Back to the future?
by Michael Corr (CEED, UiO), Cole Richards (UAF) and Eivind Straume (CEED, UiO).
Meteorological stations at Svalbard have measured a 4 C temperature rise in the last 30 years, and an average temperature increase of 0.25 C per decade (from 1912 – 2011) making Svalbard one of the most rapidly warming places in the Arctic (Øseth, 2010). According to the polar section in the IPCC report (i.e. Anisimov et al., 2007), temperatures in the Arctic are predicted to rise twice as fast as the global average, which would potentially make the Arctic Ocean ice-free within a few decades. This accelerated warming is unlike anything previously recorded. However, if we go far enough back in time the climate was much warmer than today and there have been periods with rapid climate warming comparable to the present. Evidences of that are found in the rock record of Svalbard. In the Early Eocene (~50 million years ago) there were no glaciers on Antarctica or Greenland and we find fossil wood and leafs on Svalbard indicating that it was covered by forests (e.g. Zachos et al., 2008). Fossils of crocodilian ancestors and pantodont tracks in the Arctic indicate that animal life in these “Arctic” forests was drastically different compared to the present (e.g. Markwik 1998). Also, the coal layers at Svalbard reflect large production of biogenic material which could only be produced by luxuriant vegetation. However, the coal is mostly older than Eocene. Latitudinal movement of the continents through time continuously occurs because of plate tectonics and could explain a warmer climate if Svalbard was further south. However, plate kinematic models (e.g Seton et al., 2012) based on paleomagnetic studies (e.g. Torsvik et al., 2001) places Svalbard at almost the same latitude as today, which means that the climate at high northern latitudes must have been very different.
