Satellite observations of total solar irradiance (TSI) changes
from 1978 to 2011 show that the most recent solar cycle minimum
was lower than the prior two.
This
very likely
led to a small
negative
RF of –0.04 (–0.08 to 0.00) W m
between 1986 and 2008.The best estimate of RF due to TSI changes representative for the 1750
to 2011 period is 0.05 (to 0.10) W m
–2
–2
. This is substantially smaller
than the AR4 estimate due to the addition of the latest solar cycle
and inconsistencies in how solar RF has been estimated in earlier IPCC
assessments. There is very low confidence concerning future solar forcing
estimates,
but there is
high confidence
that the TSI
RF variations
will
be
much
smaller
than
the
projected
increased
forcing
due
to
GHG
during
the forthcoming decades.
{8.4.1,
Figures
8.10,
8.11}