Tml. Wigley et al., THE OBSERVED GLOBAL WARMING RECORD - WHAT DOES IT TELL US, Proceedings of the National Academy of Sciences of the United Statesof America, 94(16), 1997, pp. 8314-8320
Global, neat-surface temperature data sets and their derivations are d
iscussed, and differences between the Jones and Intergovernmental Pane
l on Climate Change data sets are explained. Global-mean temperature c
hanges are then interpreted in terms of anthropogenic forcing influenc
es and natural variability: The inclusion of aerosol forcing improves
tile fit between modeled and observed changes hot does not improve the
agreement between the implied climate sensitivity value and the stand
ard model-based range of 1.5-4.5 degrees C equilibrium warming for a C
O2 doubling, The implied sensitivity goes from below the model-based r
ange of estimates to substantially above this range, The addition of a
solar forcing effect. further improves the fit and brings the best-fi
t sensitivity into tile middle of the model-based range, Consistency i
s further improved when internally generated changes are considered, T
his consistency, however, hides manly uncertainties that surround obse
rved data/model comparisons, These uncertainties make it impossible cu
rrently to use observed global-scale temperature changes to narrow the
uncertainty range in the climate sensitivity below that estimated dir
ectly from climate models.