Overview of the various models for ice ages in the recent past (3 MYBP to present) - Ice Ages and Interglacials: Measurements, Interpretation, and Models - page 235

Figure 8.7. Comparison of radionuclide fluxes with relative amount of ice-rafted debris over
the past 12,000 years (Bond et al., 2001).

past 10-15 years has apparently been unable to overrule the flattening of the
temperature trend as a result of the Sun settling at a high, but no longer
increasing, level of magnetic activity. Contrary to the argument of Lockwood
and Fro ¨ hlich, the Sun still appears to be the main forcing agent in global climate
change.''

Kniveton and Todd (2001) found a close correspondence between cosmic ray
flux and global precipitation eciency.
Bond et al. (2001) found close correlations between the extent of ice-rafted
debris in the North Atlantic and fluxes of nuclides produced by galactic cosmic
rays over the past 12,000 years. Figure 8.7 illustrates their results. Higher levels of
ice-rafted debris are expected to reflect warmer temperatures and these correlate
with higher nuclide production and, therefore, presumably greater cloud

formation.
Unfortunately, there does not seem to be much in the way of analysis over
time spans of several hundred thousand years. However, Kirkby et al. (2004)
analyzed the level of 10 Be over the past 220,000 years using ocean sediments in
which the chronology was set by tuning. They found that during the past 220,000