Historically, today's temperature trends are entirely within in the realm of what has taken place in the past from natural temperature variation, regardless of CO2 levels. (c3headlines.com)
However, much, if not all of the warming could be caused by natural temperature variations that are not related to humankind. (ase.tufts.edu)
Homogenized data suggested a rapid warming trend but as an ecologist, I knew homogenized temperatures are worthless for wildlife studies because the process eliminates natural temperature variations and alters the actual mean temperatures. (landscapesandcycles.net)