There is very high confidence that industrial-era natural forcing
is a small fraction of the anthropogenic forcing except for brief
periods following large volcanic eruptions. In particular, robust
evidence from satellite observations of the solar irradiance and volcanic
aerosols demonstrates a near-zero
(–0.1 to +0.1 W m
) change in
the natural forcing compared to the anthropogenic ERF increase of 1.0
(0.7 to 1.3) W m
from 1980 to 2011. The natural forcing over the last
15 years has likely offset a substantial fraction (at least 30%) of the
anthropogenic forcing. {8.5.2; Figures 8.18, 8.19, 8.20}
–2
–2