Increased CO₂ and Increased Temperature: Which Came First?

Previous analyses of Antarctic ice core data used to estimate past CO₂ and temperature changes have been inconclusive on whether global temperature increases caused atmospheric CO₂ increases or vice versa. Caillon et al. (2003) report an analysis of isotopes of argon that suggest that the rise in temperatures occurred 800 +/- 200 years before the rise in CO₂.

Reference

Caillon, N., J.P. Severinghaus, J. Jouzel, J.-M. Barnola, J. Kang, and V.Y. Lipenkov, 2003: Timing of atmospheric CO₂ and Antarctic temperature changes across Termination III. Science, 299, 1728-1731.