Table 3.

Summary of change in radiative forcing due to aerosol effects in BAU and 2020 Action scenarios

Radiative forcing (mW m−2)	Direct effect	Indirect effect	Net aerosol forcinga
Scenario
BAU	−6.7	−86	−93
2020 action	−2.8	−19	−22
Net change	3.9	67	71
	Percent change in radiative forcing (positive percentage = increased warming)
Shipping	75%	81%	81%
Transportb	2.1%	36%	38%
All human activityc	0.2%	3.6%	3.8%

^a Net sums may differ from observed sum in table due to rounding

^b 15% of anthropogenic radiative forcing, per Fuglesvedt⁴⁶

^c Comparative calculation uses ~1.8 W m⁻² vs. preindustrial level, per IPCC¹³