<http://www8.nationalacademies.org/onpinews/newsitem.aspx?RecordID=11676>
"WASHINGTON -- There is sufficient evidence from tree rings, boreholes,
retreating glaciers, and other "proxies" of past surface temperatures to
say with a high level of confidence that the last few decades of the
20th century were warmer than any comparable period in the last 400
years, according to a new report from the National Research Council."
"The report was requested by Congress after a controversy arose last
year over surface temperature reconstructions published by climatologist
Michael Mann and his colleagues in the late 1990s. The researchers
concluded that the warming of the Northern Hemisphere in the last
decades of the 20th century was unprecedented in the past thousand
years. In particular, they concluded that the 1990s were the warmest
decade, and 1998 the warmest year. Their graph depicting a rise in
temperatures at the end of a long era became known as the "hockey stick.""
Full text of report is available on-line.