Dr. Syun-Ichi Akasofu
Dr. Syun-Ichi Akasofu–founding director of the International Arctic Research Center, twice named one of the “1,000 Most Cited Scientists,” says much “Arctic warming during the last half of the last century is due to natural change.”
Actually a climate scientist, although in his own words:
“Although I am not a climatologist, it has been interesting to observe climatology from the point of view of an arctic scientist. In order for the field of climatology and IPCC to be healthy, I want to provide a few criticisms, which I hope are constructive.” 
A rebuttal to his belief that current warming is just an extension of natural warming since the LIA can be found here.
climate change details removed from wikipedia page.
Akasofu is one of the 700+ scientists listed in a report issued by the Republican minority of the [United States Senate Committee on Environment and Public Works] entitled ”More Than 700 International Scientists Dissent Over Man-Made Global Warming Claims Scientists Continue to Debunk “Consensus” in 2008 & 2009” who are said to dispute the theory of anthropogenic global warming.
‘On the Fundamental Defect in the IPCC’s Approach to Global Warming Research” by Syun-Ichi Akasofu, Climate Science: Roger Pielke Sr. Research Group Weblog, June 15, 2007
‘Two Natural Components of the Recent Climate Change: (1) The Recovery from the Little Ice Age (A Possible Cause of Global Warming) and (2) The Multi-decadal Oscillation (The Recent Halting of the Warming)”This 50MB paper in pdf format presented by Dr Syun Akasofu at the 2009 International Conference on Climate Change, New York, March 2009 is summarized at http://joannenova.com.au/2009/04/03/global-warming-a-classic-case-of-alarmism/