The impact of anthropogenic CO2 emissions: Unknows and uncertainties Soon, W. ; Baliunas, S. ; Demirchan, K. S. ; Idso, S. B. ; Kondratyev, K. Ya. ; Posmentier, E. S. Abstract Publication: Proceedings of the Russian Geographical Society Pub Date: 2001 Bibcode: 2001PRGS..133....1S