Global Temperatures, Volcanic Eruptions, and Trees that Didn’t
Bark  Including this effect, our model accounts not only for the
level of attenuation of the signal, but the delayed and smeared
out cooling as well. This is particularly striking in comparing
the behavior following both the AD 1258 and AD 1809 eruptions
(compare the green and blue curves in the insets of the figure).
Our model, for example, predicts the magnitude of the reduction
of cooling following the eruptions and the delay in the apparent
cooling evidence in the tree-ring record (i.e. in AD 1262 rather
than AD 1258). We have also included a minor additional effect
in these simulations. While volcanic aerosols cause surface
cooling due to decreased shortwave radiation at the surface,
they also lead to increased indirect, scattered light at the
surface. Plant growth benefits from indirect sunlight, and past
studies show that e.g. a Pinatubo-sized eruption (roughly
-2W/m^2 radiative forcing) can result in a 30% increase in
carbon assimilation b