Can natural or anthropogenic explanations of late-Holocene CO2 and CH4 increases be falsified?

Can natural or anthropogenic explanations of late-Holocene CO2 and CH4 increases be falsified?  

Publication Date:  2010-03-30
Creator:  W.F. Ruddiman
J.E. Kutzbach
S.J. Vavrus
Publisher.Display:  Sage Publishing
Subjects.Display:  Climate change
Land use
Agriculture
carbon--isotopes
Source Institution:  Florida International University
Can natural or anthropogenic explanations of late-Holocene CO2 and CH4 increases be falsified?
Evidence for warmer interglacials in East Antarctic ice cores

Evidence for warmer interglacials in East Antarctic ice cores  

Publication Date:  2009-11-19
Creator:  L.C. Sime
E.W. Wolff
K.I.C. Oliver
J.C. Tindall
Publisher.Display:  Macmillan Publishers Limited
Subjects.Display:  Climate change
ice cores
East Antarctica (Antarctica)
isotopes
Source Institution:  Florida International University
Evidence for warmer interglacials in East Antarctic ice cores