A paleoclimatic perspective on contemporary Arctic climate (Invited Presentation)

Studies of global or hemispheric temperature changes have shown that the late 20th century was the warmest period in (at least) the last millennium. Furthermore, the coldest decades of the last century (the nadir of the "Little Ice Age", which spanned ~A.D.1250-1850) were among the coldest times of the late Holocene. Thus, the world has experienced both the warmest and the coldest extremes of the last few thousand years within a brief interval of <200 years. These changes are revealed in numerous paleoclimatic records from the Arctic and sub-Arctic (ice cores, tree rings, lake sediments). Temperature changes that GCM simulations project for the 21st century changes will be huge, especially in the Arctic. This leads us to ask: when was the Arctic warmer than today and what lessons can we learn from paleoclimatic records about past environmental changes during warm intervals?