39
allow physical variables within the troposphere to respond to perturbations, except
for those ocean and sea ice variables. For computations of RF, all surface and tropospheric conditions are kept fixed. Quoting Box 8.1 of IPCC (2013), “the calculation
of ERF requires longer simulations with more complex models than the calculation
of RF, but the inclusion of the additional rapid adjustments makes ERF a better
indicator of the eventual global mean temperature response, especially for aerosols”. We have used a mixture of ΔRF and ΔERF values for Fig. 1.4 because this is
all that is available from Chap. 8 of IPCC (2013). Table 1.3 provides numerical
estimates of the value, uncertainty, and origin of the data used in Fig. 1.4. All uncertainties represent 5–95 % confidence intervals and are given as a range, rather than
a plus and minus value, since some are asymmetric about the mean.
Figure 1.5 shows a profile of the change in temperature over the time period
1959–2012, based on radiosonde observations collected in the latitude range 30°S
to 30°N (Sherwood and Nishant 2015). Data reflect the Iterative Universal Kriging
Table 1.3 ΔRF values used in Fig. 1.4
Term
ΔRF
(W m
−2
)
Range of ΔRF
(W m
−2
)
Origin within Chap. 8 of
IPCC (2013)
CO 2
1.82
1.63–2.01
Table 8.2, RF
CH 4
0.48
0.43–0.53
Table 8.2, RF
N 2 O
0.17
0.14–0.20
Table 8.2, RF
ODS
a
0.33
0.297–0.363
Table 8.2, RF
Other F-Gases
b
0.03
0.027–0.033
Table 8.2, RF
Tropospheric O 3
0.4
0.2–0.6
Table 8.6, RF
Stratospheric O 3
−0.05
−0.15 to 0.05
Table 8.6, RF
Stratospheric H 2 O
c
0.07
0.02–0.12
Table 8.6, RF
Contrails and Contrail-Induced
Cirrus
0.05
0.02–0.15
Table 8.6, ERF
Surface Reflectivity: Land Use
Change
−0.15
−0.25 to −0.05 Table 8.6, RF
Surface Refl.: Black Carbon on
Snow
0.04
0.02–0.09
Table 8.6, RF
Aerosol Direct Effect
−0.45
−0.95 to 0.05
Table 8.6, ERF
Aerosol-Cloud Interaction
−0.45
−1.2 to 0.0
Table 8.6, ERF
Total Anthropogenic
2.3
1.1–3.3
Table 8.6, ERF
Solar Irradiance
0.05
0.0–0.10
Table 8.6, RF
a The definition of Ozone Depleting Substances used in Chap. 8 of IPCC (2013) combines the RF
of climate due to CFC-11, CFC-12, CFC-13, CFC-113, CFC-114, CFC-115, HCFC-141b, HCFC142b, CH 3 CCl 3 , CCl 4 , Halon-1211, and Halon-1301. The IPCC (2013) definition appears to
neglect Halon-1202, Halon-2402, CH 3 Cl, and CH 3 Br. The ΔRF of these four compounds is quite
small, less than 0.002 W m
−2
, so Fig. 1.4 would look identical had these four gases been considered
b
This term considers the RF of climate due to HFCs, PFCs, SF 6 , and a few other long-lived fluorinated species. The IPCC (2013) definition combines the RF of climate due to HFC-23, HFC-32,
HFC-125, HFC-134a, HFC-143a, HFC-152a, CF 4 , C 2 F 6 , SF 6 , SO 2 F 6 , and NF 3
c This term represents the RF of climate due to the increase in stratospheric H 2 O driven by rising
levels of tropospheric CH 4 . It does not include radiative effects of changes in stratospheric H 2 O that
occur in response to global warming (Solomon et al. 2010)
1.3 Methods
allow physical variables within the troposphere to respond to perturbations, except
for those ocean and sea ice variables. For computations of RF, all surface and tropospheric conditions are kept fixed. Quoting Box 8.1 of IPCC (2013), “the calculation
of ERF requires longer simulations with more complex models than the calculation
of RF, but the inclusion of the additional rapid adjustments makes ERF a better
indicator of the eventual global mean temperature response, especially for aerosols”. We have used a mixture of ΔRF and ΔERF values for Fig. 1.4 because this is
all that is available from Chap. 8 of IPCC (2013). Table 1.3 provides numerical
estimates of the value, uncertainty, and origin of the data used in Fig. 1.4. All uncertainties represent 5–95 % confidence intervals and are given as a range, rather than
a plus and minus value, since some are asymmetric about the mean.
Figure 1.5 shows a profile of the change in temperature over the time period
1959–2012, based on radiosonde observations collected in the latitude range 30°S
to 30°N (Sherwood and Nishant 2015). Data reflect the Iterative Universal Kriging
Table 1.3 ΔRF values used in Fig. 1.4
Term
ΔRF
(W m
−2
)
Range of ΔRF
(W m
−2
)
Origin within Chap. 8 of
IPCC (2013)
CO 2
1.82
1.63–2.01
Table 8.2, RF
CH 4
0.48
0.43–0.53
Table 8.2, RF
N 2 O
0.17
0.14–0.20
Table 8.2, RF
ODS
a
0.33
0.297–0.363
Table 8.2, RF
Other F-Gases
b
0.03
0.027–0.033
Table 8.2, RF
Tropospheric O 3
0.4
0.2–0.6
Table 8.6, RF
Stratospheric O 3
−0.05
−0.15 to 0.05
Table 8.6, RF
Stratospheric H 2 O
c
0.07
0.02–0.12
Table 8.6, RF
Contrails and Contrail-Induced
Cirrus
0.05
0.02–0.15
Table 8.6, ERF
Surface Reflectivity: Land Use
Change
−0.15
−0.25 to −0.05 Table 8.6, RF
Surface Refl.: Black Carbon on
Snow
0.04
0.02–0.09
Table 8.6, RF
Aerosol Direct Effect
−0.45
−0.95 to 0.05
Table 8.6, ERF
Aerosol-Cloud Interaction
−0.45
−1.2 to 0.0
Table 8.6, ERF
Total Anthropogenic
2.3
1.1–3.3
Table 8.6, ERF
Solar Irradiance
0.05
0.0–0.10
Table 8.6, RF
a The definition of Ozone Depleting Substances used in Chap. 8 of IPCC (2013) combines the RF
of climate due to CFC-11, CFC-12, CFC-13, CFC-113, CFC-114, CFC-115, HCFC-141b, HCFC142b, CH 3 CCl 3 , CCl 4 , Halon-1211, and Halon-1301. The IPCC (2013) definition appears to
neglect Halon-1202, Halon-2402, CH 3 Cl, and CH 3 Br. The ΔRF of these four compounds is quite
small, less than 0.002 W m
−2
, so Fig. 1.4 would look identical had these four gases been considered
b
This term considers the RF of climate due to HFCs, PFCs, SF 6 , and a few other long-lived fluorinated species. The IPCC (2013) definition combines the RF of climate due to HFC-23, HFC-32,
HFC-125, HFC-134a, HFC-143a, HFC-152a, CF 4 , C 2 F 6 , SF 6 , SO 2 F 6 , and NF 3
c This term represents the RF of climate due to the increase in stratospheric H 2 O driven by rising
levels of tropospheric CH 4 . It does not include radiative effects of changes in stratospheric H 2 O that
occur in response to global warming (Solomon et al. 2010)
1.3 Methods