"what if ice core samples going back 450K years show that it isnt something new ?"
What if everything going back 120K years says it is?
Unprecedented recent summer warmth in Arctic Canada
Gifford H. Miller1,2,*, Scott J. Lehman1, Kurt A. Refsnider1,2,3, John R. Southon4, Yafang Zhong5Article first published online: 4 NOV 2013
DOI: 10.1002/2013GL057188
©2013. American Geophysical Union. All Rights Reserved.
Abstract
[1] Arctic air temperatures have increased in recent decades, along with documented reductions in sea ice, glacier size, and snow cover. However, the extent to which recent Arctic warming has been anomalous with respect to long-term natural climate variability remains uncertain. Here we use 145 radiocarbon dates on rooted tundra plants revealed by receding cold-based ice caps in the eastern Canadian Arctic to show that 5000?years of regional summertime cooling has been reversed, with average summer temperatures of the last ~100?years now higher than during any century in more than 44,000?years, including the peak warmth of the early Holocene when high-latitude summer insolation was 9% greater than present. Reconstructed changes in snowline elevation suggest that summers cooled ~2.7°C over the past 5000?years, approximately twice the response predicted by Coupled Model Intercomparison Project Phase 5 climate models. Our results indicate that anthropogenic increases in greenhouse gases have led to unprecedented regional warmth.
onlinelibrary.wiley.com 
Average summer temperatures in the Eastern Canadian Arctic during the last 100 years are higher now than during any century in the past 44,000 years and perhaps as long ago as 120,000 years, says a new INSTAAR study. - with video
instaar.colorado.edu
earlier study hockey stick alert
New research shows that the Arctic reversed a long-term cooling trend and began warming rapidly in recent decades. The blue line shows estimates of Arctic temperatures over the last 2,000 years, based on proxy records from lake sediments, ice cores and tree rings. The green line shows the long-term cooling trend. The red line shows the recent warming based on actual observations. A 2000-year transient climate simulation with NCAR?s Community Climate System Model shows the same overall temperature decrease as does the proxy temperature reconstruction, which gives scientists confidence that their estimates are accurate. [ENLARGE] (Courtesy Science, modified by UCAR.) News media terms of use*
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