
Figure 2c from
Mann and Jones (2003),
Global surface temperatures over the past two millennia
GEOPHYSICAL RESEARCH LETTERS, VOL. 30, NO. 15, 1820.
Caption: Hemispheric temperature reconstructions (‘standard
reconstructions’ based on area and local correlation
weighting, shown as thick blue). All series are anomalies
based on 1961–1990 instrumental reference period (mean
shown by dashed line), and smoothed with a 40 year
lowpass filter. Smoothed instrumental series are shown by
thick red curve (the constraint employed by the filter
preserves the late 20th century trend). 95% confidence
intervals for the standard reconstructions are shown by
yellow shading. .. (c) global mean (average of NH and SH)
surface temperature reconstruction.