Climatologist Dr. Judith Curry: ‘There is no unambiguous way to separate natural from anthropogenic climate change’
'True to its classic wicked messiness, there is no unambiguous way to separate natural from anthropogenic climate change, or to separate climate change impacts from other confounding factors, or to separate the solutions from the broader issues of population increase, underdevelopment, mismanagement, and corrupt governments.'
http://judithcurry.com/2014/04/26/stavins-and-tol-on-ipcc-wg3/