Tj. Crowley et Ky. Kim, Modeling the temperature response to forced climate change over the last six centuries, GEOPHYS R L, 26(13), 1999, pp. 1901-1904
Development of improved proxy estimates of climate forcing and temperature
change over the past six centuries provides a new opportunity to examine th
e role of forced variability in the climate system. We utilize an energy ba
lance model to estimate that as much as 18-34% of low frequency temperature
change over the preanthropogenic interval could be forced by volcanism and
solar variability. Comparison of residuals with estimates of unforced vari
ability from control runs of coupled models indicates that the spectra of t
he two time series agree at the 90% significance level.