TSSM-1
TSSM
This supplementary material should be cited as:
Stocker, T.F., D. Qin, G.-K. Plattner, L.V. Alexander, S.K. Allen, N.L. Bindoff, F.-M. Bréon, J.A. Church, U. Cubasch,
S. Emori, P. Forster, P. Friedlingstein, N. Gillett, J.M. Gregory, D.L. Hartmann, E. Jansen, B. Kirtman, R. Knutti, K.
Krishna Kumar, P. Lemke, J. Marotzke, V. Masson-Delmotte, G.A. Meehl, I.I. Mokhov, S. Piao, V. Ramaswamy, D.
Randall, M. Rhein, M. Rojas, C. Sabine, D. Shindell, L.D. Talley, D.G. Vaughan and S.-P. Xie, 2013: Technical Sum-
mary Supplementary Material. In: Climate Change 2013: The Physical Science Basis. Contribution of Working
Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Stocker, T.F., D. Qin,
G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley (eds.)]. Available from
www.climatechange2013.org and www.ipcc.ch.
Coordinating Lead Authors:
Thomas F. Stocker (Switzerland), Qin Dahe (China), Gian-Kasper Plattner (Switzerland)
Lead Authors:
Lisa V. Alexander (Australia), Simon K. Allen (Switzerland/New Zealand), Nathaniel L. Bindoff
(Australia), François-Marie Bréon (France), John A. Church (Australia), Ulrich Cubasch
(Germany), Seita Emori (Japan), Piers Forster (UK), Pierre Friedlingstein (UK/Belgium), Nathan
Gillett (Canada), Jonathan M. Gregory (UK), Dennis L. Hartmann (USA), Eystein Jansen (Norway),
Ben Kirtman (USA), Reto Knutti (Switzerland), Krishna Kumar Kanikicharla (India), Peter Lemke
(Germany), Jochem Marotzke (Germany), Valérie Masson-Delmotte (France), Gerald A. Meehl
(USA), Igor I. Mokhov (Russian Federation), Shilong Piao (China), Venkatachalam Ramaswamy
(USA), David Randall (USA), Monika Rhein (Germany), Maisa Rojas (Chile), Christopher Sabine
(USA), Drew Shindell (USA), Lynne D. Talley (USA), David G. Vaughan (UK), Shang-Ping Xie
(USA)
Contributing Authors:
Myles R. Allen (UK), Olivier Boucher (France), Don Chambers (USA), Jens Hesselbjerg
Christensen (Denmark), Philippe Ciais (France), Peter U. Clark (USA), Matthew Collins (UK),
Josefino C. Comiso (USA), Viviane Vasconcellos de Menezes (Australia/Brazil), Richard A. Feely
(USA), Thierry Fichefet (Belgium), Gregory Flato (Canada), Jesús Fidel González Rouco (Spain),
Ed Hawkins (UK), Paul J. Hezel (Belgium/USA), Gregory C. Johnson (USA), Simon A. Josey (UK),
Georg Kaser (Austria/Italy), Albert M.G. Klein Tank (Netherlands), Janina Körper (Germany),
Gunnar Myhre (Norway), Timothy Osborn (UK), Scott B. Power (Australia), Stephen R. Rintoul
(Australia), Joeri Rogelj (Switzerland/Belgium), Matilde Rusticucci (Argentina), Michael Schulz
(Germany), Jan Sedláček (Switzerland), Peter A. Stott (UK), Rowan Sutton (UK), Peter W. Thorne
(USA/Norway/UK), Donald Wuebbles (USA)
Review Editors:
Sylvie Joussaume (France), Joyce Penner (USA), Fredolin Tangang (Malaysia)
Technical Summary
Supplementary Material
TSSM
TSSM-2
Table of Contents
TS.SM.1 Notes and Technical Details on
Observed Global Surface Temperature
Figures in the Summary for
Policymakers – Figure SPM.1 ................... TS-SM-3
TS.SM.2 Notes and Technical Details on
Observed Change in Precipitation
Over Land Figures in the Summary
for Policymakers – Figure SPM.2 ............ TS-SM-3
TS.SM.3 Notes and Technical Details on Observed
Indicators of a Changing Global
Climate Figures for the Summary
for Policymakers – Figure SPM.3 ............ TS-SM-3
TS.SM.4 Notes and Technical Details on
Observed Changes in the Global
Carbon Cycle Figures in the Summary
for Policymakers – Figure SPM.4 ............ TS-SM-5
TS.SM.5 Notes and Technical Details on
Radiative Forcing Estimates Figure in
the Summary for Policy Makers –
Figure SPM.5 ................................................. TS-SM-6
TS.SM.6 Notes and Technical Details on Comparison
of Observed and Simulated Climate
Change Figures for the Summary
for Policymakers – Figure SPM.6 ............ TS-SM-6
TS.SM.7 Notes and Technical Details on CMIP5
Simulated Time Series Figures in the
Summary for Policymakers –
Figure SPM.7 ................................................. TS-SM-7
TS.SM.8 Notes and Technical Details on Maps
Showing CMIP5 Results in the
Summary for Policymakers –
Figure SPM.8 ............................................... TS-SM-11
TS.SM.9 Notes and Technical Details on the Sea Level
Projection Figure for the Summary
for Policymakers – Figure SPM.9 .......... TS-SM-15
TS.SM.10 Notes and Technical Details on the Summary
for Policymakers Figure Plotting Global
Mean Temperature Increase as a Function
of Cumulative Total Global CO
2
Emissions – Figure SPM.10 ..................... TS-SM-15
References ......................................................................... TS-SM-17
TSSM
Technical Summary Supplementary Material
TSSM-3
TS.SM.1 Notes and Technical Details on Observed
Global Surface Temperature Figures in
the Summary for Policymakers –
Figure SPM.1
Data and programming code (IDL) used to create Summary for Policy-
makers and Technical Summary figures originating from Sections 2.4
and 2.5 of Chapter 2 can be obtained from the IPCC WGI AR5 website
www.climatechange2013.org.
TS.SM.1.1 Annual and Decadal Global Surface
Temperature Anomalies – Figure SPM.1a
Global Mean Surface Temperature (GMST) anomalies as provided by
the dataset producers are given normalized relative to a 1961–1990
climatology from the latest version (as at 15 March 2013) of three
combined Land-Surface Air Temperature (LSAT) and Sea Surface Tem-
perature (SST) datasets. These combined datasets and the correspond-
ing colours used in Figure SPM.1a are:
HadCRUT4 (version 4.1.1.0) – black
NASA GISS – blue
NCDC MLOST (version 3.5.2) – orange.
An overview of methodological diversity between these three temper-
ature datasets is provided in Table 2.SM.6 of the Supplementary Mate-
rial to Chapter 2, and full comprehensive details on the construction
process for these datasets are provided in the references cited in this
table. For time-series of LSAT only, and SST only, the reader is referred
to Figure TS.1.
For the decadal anomalies, 90% confidence intervals are shown for the
HadCRUT4 dataset (based on Morice et al., 2012).
TS.SM.1.2 Maps of Observed Changes in Surface
Temperature – Figure SPM.1b
Maps of observed changes in surface temperature are based on trends
calculated from the 3 datasets listed above for the period 1901–2012.
See the Supplementary Material of Chapter 2 for a detailed description
of the methodology used for trend and uncertainty calculations (Sec-
tion 2.SM.3.3). Trends have been calculated only for those grid boxes
with greater than 70% complete records and more than 20% data
availability in the first and last 10% of the time period. White areas
indicate incomplete or missing data. Black plus signs (+) indicate grid
boxes where trends are significant at the 2-tailed 10% significance
level (i.e., a trend of zero lies outside the 90% confidence interval).
The Technical Summary provides maps for all 3 datasets (Figure TS.2),
while the Summary for Policymakers provides a map based on NCDC
MLOST only (Figure SPM.1b).
TS.SM.2 Notes and Technical Details on
Observed Change in Precipitation
Over Land Figures in the Summary
for Policymakers – Figure SPM.2
Data and programming code (IDL) used to create Summary for Policy-
makers and Technical Summary figures originating from Sections 2.4
and 2.5 of Chapter 2 can be obtained from the IPCC WGI AR5 website
www.climatechange2013.org.
TS.SM.2.1 Map of Observed Changes in Precipitation
Over Land – Figure SPM.2
Maps of observed changes in annual precipitation over land show
trends calculated from 3 datasets:
CRU TS 3.10.01 (updated from Mitchell and Jones, 2005)
GHCN V2 (updated through 2011; Vose et al., 1992)
GPCC V6 (Becker et al., 2013)
Trends in annual precipitation are expressed per decade, and are calcu-
lated for the time periods 1901–2010 and 1951–2010. See the Supple-
mentary Material of Chapter 2 for a detailed description of the meth-
odology used for trend and uncertainty calculations (Section 2.SM.3.3).
Trends have been calculated only for those grid boxes with greater
than 70% complete records and more than 20% data availability in
first and last 10% of the time period. White areas indicate incomplete
or missing data. Black plus signs (+) indicate grid boxes where trends
are significant at the 2-tailed 10% significance level (i.e., a trend of
zero lies outside the 90% confidence interval).
The Technical Summary provides maps for all 3 datasets (TS TFE.1,
Figure 2), while the Summary for Policymakers provides a map based
on GPCC only (Figure SPM.2).
TS.SM.3 Notes and Technical Details on
Observed Indicators of a Changing
Global Climate Figures for the Summary
for Policymakers – Figure SPM.3
This material documents the provenance of the data and plotting
procedures that were used to create Figure SPM.3 in the IPCC WGI
Fifth Assessment Report. This figure is closely derived from Figure TS.1
and FAQ 2.1, Figure 2 (see Chapter 2 Supplementary Material Section
2.SM.5), but includes fewer observed indicators. In addition, Figure
SPM.3 includes an estimate of uncertainty for those datasets where
this is available and has been assessed, illustrated with shading. Figure
SPM.3 includes datasets and parameters assessed in Chapters 3 (ocean
heat content, sea level), and 4 (snow cover, sea ice).
TSSM
Technical Summary Supplementary Material
TSSM-4
TS.SM.3.1 Northern Hemisphere Spring Snow Cover –
Figure SPM.3a
TS.SM.3.1.1 Datasets
Green: Northern Hemisphere annual March-April average snow-cover
extent based on an updated series from Brown and Robinson (2011),
1922–2012.
Shaded uncertainty estimate indicated by the 95% confidence interval.
TS.SM.3.1.2 Plotting Techniques
Annual values are plotted.
TS.SM.3.2 Arctic Summer Sea Ice Extent – Figure SPM.3b
All datasets provide Arctic annual July-August-September average sea
ice extent.
Green: Updated from Walsh and Chapman (2001). Annual values are
from 1900–1978.
Blue: Hadley Centre Sea Ice and Sea Surface Temperature dataset (Had-
ISST1.2) (Rayner et al., 2003). Annual values are from 1900–1939 and
1953–2012. Values are excluded for the period 1940–1952 because
the available data showed no change. It was a period when in situ data
were very sparse and the gaps were filled in for completeness with
climatology. For this assessment, this was not considered sufficiently
robust and therefore the data during the period were excluded from
the time series.
Red: Bootstrap algorithm (SBA) applied to data from the Scanning Mul-
tichannel Microwave Radiometer (SMMR) (updated from Comiso and
Nishio, 2008). Annual values are from 1979–2012.
Black: NASA Team algorithm (NT1) applied to data from the Special
Sensor Microwave/Imager (SSM/I) (Cavalieri et al., 1984) – updated
in Cavalieri and Parkinson (2012) and Parkinson and Cavalieri (2012).
Annual values are from 1979–2011.
Yellow: Bootstrap algorithm (ABA) applied to data from the Advanced
Microwave Scanning Radiometer - Earth Observing System (AMSR-
E) (updated from Comiso and Nishio, 2008). Annual values are from
2002–2011.
Orange: Revised NASA Team algorithm (NT2) applied to data from the
Advanced Microwave Scanning Radiometer - Earth Observing System
(AMSR-E) (updated from Markus and Cavalieri, 2000). Annual values
are from 2002–2011.
Uncertainty estimates for each data point in the plots have been cal-
culated based on the interannual variability of the ice extents. The sys-
tematic errors are not considered because they are generally unknown
and are expected to be approximately constant from one year to
another and would not change the results of trend analyses signifi-
cantly. The interannual variability of the extent and actual area of the
sea ice cover during the satellite era (since 1979) can be quantified
accurately because of global coverage at good temporal resolution and
the high contrast in the signature of ice free and ice covered oceans.
The uncertainty (shaded range) that is shown is 1 standard deviation
of the more than 30 years of satellite data, assuming a Gaussian dis-
tribution. The standard deviation is calculated after the data have been
linearly detrended.
For the pre-satellite data (pre 1979), the true interannual variability is
not known because available data are sparse and limited to only a few
locations. Based on the expected quality of the Walsh and Chapman
(2001) data and because of the lack of a better procedure, we use
1.75 standard deviations for the period 1880 to 1952 when data were
sparse and 1.5 standard deviation for the period 1953 to 1978 when
significantly more data were available. For the HadISST1.2 data set,
which includes both pre- and post-satellite data (Rayner et al., 2003),
we use 1 standard deviation for the entire period since 1900, calculat-
ed after the data has been linearly detrended.
TS.SM.3.2.2 Plotting Techniques
Annual values are plotted.
TS.SM.3.3 Global Average Upper Ocean Heat Content –
Figure SPM.3c
TS.SM.3.3.1 Datasets
All datasets provide global annual upper-ocean (0 to 700 m depth)
heat content anomalies.
Blue: Updated from Palmer et al. (2007). Annual values are from 1950–
2011.
Green: Updated from Domingues et al. (2008). Annual values, smoothed
with a 3-year running mean, are from 1950–2011.
Yellow: Updated from Ishii and Kimoto (2009). Annual values are from
1950–2011.
Orange: Updated from Smith and Murphy (2007). Annual values are
from 1950–2010.
Black: Updated from Levitus et al. (2012). Annual values are from
1955–2011.
Uncertainty estimates are as reported in the cited publications. These
are one standard error of the mean, except for Levitus et al. (2012)
which provide one standard deviation. No uncertainty estimate is
available for Smith and Murphy (2007).
TS.SM.3.3.2 Plotting Techniques
The published ocean heat content anomaly datasets are relative to dif-
ferent climatological reference periods. Therefore, the datasets have
been aligned in Figure SPM.3c for the period 2006–2010, five years
that are well measured by Argo, and then plotted relative to the result-
TSSM
Technical Summary Supplementary Material
TSSM-5
ing mean of all curves for 1970, a time when the increasing availability
of annual data from XBTs causes the uncertainty estimates to reduce
considerably. Specifically the alignment procedure for Figure SPM.3c
involved the following steps:
Obtain all five upper ocean heat content anomaly time series.
1. Recognize that all the time-series values are annual values, cen-
tered on the middle of calendar years.
2. Find the average value of each time series for the years 2006–2010.
3. Subtract the average 2006–2010 value for each time series from
that specific time-series.
4. Find the value of each time series for the year 1970.
5. Average these five values from the year 1970.
6. Subtract this 1970 average value from all of the time-series.
TS.SM.3.4 Global Average Sea Level – Figure SPM.3d
TS.SM.3.4.1 Datasets
Black: Church and White (2011) tide gauge reconstruction. Annual
values are from 1900–2009.
Yellow: Jevrejeva et al. (2008) tide gauge reconstruction. Annual values
are from 1900–2002.
Green: Ray and Douglas (2011) tide gauge reconstruction. Annual
values are from 1900–2007.
Red: Nerem et al. (2010) satellite altimetry. A 1-year moving average
boxcar filter has been applied to give annual values from 1993–2009.
Shaded uncertainty estimates are one standard error as reported in
the cited publications. The one standard error on the 1-year averaged
altimetry data (Nerem et al., 2010) is estimated at ±1 mm, and thus
considerably smaller than for all other datasets.
TS.SM.3.4.2 Plotting Techniques
The published Global Mean Sea Level (GMSL) datasets use arbitrary
and different reference periods where they start from zero. Further-
more, the altimetry data begins only in 1993. Therefore, the datasets
have been aligned in Figure SPM.3d to a common reference period of
time using the following steps:
1. The longest running record (Church and White, 2011) is taken as the
reference to which all other datasets are aligned.
2. GMSL from Church and White (2011) is calculated relative to the
average for the period 1900–1905, and the resulting value for the
year 1993 (127 mm) is identified.
3. All other records are then adjusted to give the same value of 127
mm in 1993 (i.e., for each dataset the offset required to give 127
mm in 1993 is applied to all annual values in that dataset).
TS.SM.4 Notes and Technical Details on
Observed Changes in the Global
Carbon Cycle Figures in the Summary
for Policymakers – Figure SPM.4
TS.SM.4.1 Atmospheric Concentrations of Carbon
Dioxide – Figure SPM.4a
The top panel of Figure TS.5, and panel (a) of Figure SPM.4 show time
series of atmospheric concentrations of carbon dioxide (CO
2
). CO
2
con-
centrations are expressed as a mole fraction in dry air, micromol/mol,
abbreviated as ppm. Time series are shown for the Mauna Loa Obser-
vatory (red in Figure SPM.4a), and South Pole (black in Figure SPM.4a).
Data were accessed from the following sources (active at the time of
publication):
1. Mauna Loa Observatory
ftp://ftp.cmdl.noaa.gov/ccg/co2/trends/co2_mm_mlo.txt.
Monthly averages are plotted from March 1958 to August 2012. For
further details on the measurements see Keeling et al. (1976a) and
Thoning et al. (1989).
2. South Pole
http://scrippsco2.ucsd.edu/data/flask_co2_and_isotopic/
monthly_co2/monthly_spo.csv
Monthly averages are plotted from June 1957 to February 2012. For
further details on the measurements see Keeling et al. (1976b; 2001).
TS.SM.4.2 Ocean Surface Carbon Dioxide and
In Situ pH – Figure SPM.4b
The top panel of Figure TS.5, and panel (b) of Figure SPM.4 show time
series of observed partial pressure of dissolved CO
2
(pCO
2
given in
µatm) at the ocean surface, together with time series of ocean surface
in situ pH (total scale). All ocean time series are plotted as 12-month
running means (6 months before to 6 months after the sample date)
for each 6-month period centered on 1 January and 2 July of each year.
Data for both pCO
2
and in situ pH were measured at the following
stations and obtained from the following sources (active at the time
of publication):
1. Hawaii Ocean Time-Series program (HOT) from the station ALOHA
(updated from, Dore et al., 2009)
http://hahana.soest.hawaii.edu/hot/products/HOT_surface_CO2.txt
Shown as light green and light blue time series in Figure SPM.4b,
for in situ pH and pCO
2
respectably. Data were plotted for the period
1988–2011.
Further technical details regarding the data are available from the
readme file: http://hahana.soest.hawaii.edu/hot/products/HOT_
surface_CO2_readme.pdf.
TSSM
Technical Summary Supplementary Material
TSSM-6
2. Bermuda Atlantic Time-Series Study (BATS):
http://bats.bios.edu/bats_form_bottle.html
Shown as green and blue time series in Figure SPM.4b, for in situ pH
and pCO
2
, respectively, but not shown in Figure TS.5. Data were plotted
for the period 1991 – 2011.
Measured dissolved inorganic carbon (DIC) and total alkalinity (TA) at
in situ temperature were used to calculate pH on the total scale as well
as pCO
2
in μatm.
Further technical details are described in Bates (2007).
3. European Station for Time series in the Ocean (ESTOC; see
González-Dávila and Santana-Casiano, 2009):
http://cdiac.ornl.gov/ftp/oceans/ESTOC_data
Shown as dark green and dark blue time series in Figure SPM.4b, for in
situ pH and pCO
2
, respectively, but not shown in Figure TS.5. Data were
plotted for the period 1996–2009.
Further technical details regarding the data are available from
González-Dávila (2010).
Note that the data for Figure SPM.4 (and Figure TS.5) provided at
the external sources cited above may be subject to revision based on
recalibration, and other quality control procedures conducted over
time by the data providers.
TS.SM.5 Notes and Technical Details on Radiative
Forcing Estimates Figure in the Summary
for Policy Makers – Figure SPM.5
This material documents the underlying traceability for values that
were used to create Figure SPM.5 in the IPCC WG1 Fifth Assessment
Report. This figure is closely related to Figures TS.6 and TS.7 and Chap-
ter 8, Figures 8.14 to 8.18. The reader is therefore referred to the Sup-
plementary Material of Chapter 8 for detailed information on methods
and sources used to estimate forcing values.
Figure SPM.5 (and Figure TS.7) plots Radiative Forcing (RF) estimates in
2011 relative to 1750 and aggregated uncertainties for the main drivers
of climate change. This figure is different from similar figures shown in
previous IPCC report SPMs (though an analogous figure was shown in
Chapter 2 of AR4) as it evaluates the RF based on the emissions rather
than the concentration changes. An emitted compound changes the
atmospheric concentration of the same substance but may also impact
that of other atmospheric constituents through chemistry processes.
Values are global average RF, partitioned according to the emitted
compounds or processes that result in a combination of drivers. In cal-
culations of RF for well-mixed greenhouse gases and aerosols in this
report, physical variables, except for the ocean and sea ice, are allowed
to respond to perturbations with rapid adjustments. The resulting forc-
ing is called Effective Radiative Forcing (ERF) in the underlying report.
For all drivers other than well-mixed greenhouse gases and aerosols,
rapid adjustments are less well characterized and assumed to be small,
and thus the traditional RF is used.
The ‘level of confidence’ given in Figure SPM.5 is based on Table 8.5.
For the main emitted compounds of CO
2
, CH
4
, Halocarbons, N
2
O, CO,
NMVOC and NO
x
, the underlying values, their sources, and uncertain-
ties can be found in the Chapter 8 Supplementary Material, Tables
8.SM.6 and 8.SM.7.
The value of –0.27 W m
–2
for aerosols and precursors shown in Figure
SPM.5 results from –0.35 W m
–2
from RFari (Table 8.6) with the addi-
tion of 0.04 W m
–2
from BC-on-snow and the subtraction of the small
nitrate contribution from NO
x
of –0.04 W m
–2
(Table 8.SM.6).
The value of –0.55 W m
–2
for cloud adjustments due to aerosols given
in Figure SPM.5 results from the combination of ERFaci –0.45 [–1.2 to
0.0] W m
–2
and rapid adjustment of ari –0.1 [–0.3 to +0.1] W m
–2
as
reported in Figure TS.7. Detailed information can be found in Chapter 8
and the Chapter 8 Supplementary Material, Table 8.SM.6.
The values for albedo changes due to land use and changes in solar
irradiance come from Table 8.6 of Chapter 8.
Total anthropogenic RF relative to 1750 is based on values given in
Table 8.6 (for 2011) and Figure 8.18 (values for 1950 and 1980 given
in the caption).
TS.SM.6 Notes and Technical Details on
Comparison of Observed and Simulated
Climate Change Figures for the Summary
for Policymakers – Figure SPM.6
Figure SPM.6 and the related Figure TS.12 are reduced versions of
Figure 10.21 in Chapter 10. The reader is therefore referred to the
detailed description of the main components of Figure 10.21 for data-
sets and methods used (see the Chapter 10 Supplementary Material,
Section 10.SM.1). Here, mainly the differences of Figure SPM.6 and
TS.12 from Figure 10.21 are listed.
Figures SPM.6 and TS.12 show time series of decadal average, plotted
on a common axis and at the centre of each decade. The decadal aver-
ages are taken from the annual time series that Figure 10.21 is based
on. Figure TS.12 features the multi-model mean as dark blue and dark
red line, while Figure SPM.6 only features the 5–95% confidence inter-
val. Note that the precipitation plot from Figure 10.21 are not included
in the Technical Summary and SPM versions of this figure.
TS.SM.6.1 Continental Temperatures
The same model simulations and observational data sets are used as
for Figure 10.21. Continental land areas are based on the IPCC Special
Report on Managing the Risks of Extreme Events and Disasters to
Advance Climate Change Adaptation (SREX) defined regions (IPCC,
2012) shown pictorially in the bottom right most panel of Figure 10.7.
Temperature anomalies in Figure SPM.6 are with respect to 1880–1919
(except for Antarctica where anomalies are relative to 1950–2010).
TSSM
Technical Summary Supplementary Material
TSSM-7
TS.SM.6.2 Ocean Heat Content
The same model simulations and observational data sets are used as
for Figure 10.21.
TS.SM.6.3 Sea Ice
The same model simulations and observational data sets are used as
for Figure 10.21.
TS.SM.6.4 Data Quality
For land and ocean surface temperatures panels, solid lines indicate
where data spatial coverage of areas being examined is above 50%
coverage and dashed lines where coverage is below 50%. For example,
data coverage of Antarctica never goes above 50% of the land area of
the continent. For ocean heat content and sea-ice panels, the solid line
is where the coverage of data is good and higher in quality, and the
dashed line is where the data coverage is only adequate, based respec-
tively on the spatial coverage and instrument type and on the presence
of satellite measurements.
TS.SM.7 Notes and Technical Details on CMIP5
Simulated Time Series Figures in the
Summary for Policymakers –
Figure SPM.7
This material documents the provenance of the data and plotting
procedures that were used to create Figure SPM.7, based on Climate
Model Intercomparison Project Phase 5 (CMIP5) model results as of
March, 2013. This figure is closely derived from Figures12.5 and TS.15
(global average surface temperature), 12.28 and TS.17 (sea ice), 6.28
and TS.20a (ocean surface pH), but includes fewer model scenarios. The
reader is referred to the Technical Summary and the Chapters 12 and 6
where all RCP scenarios are given for the respective quantity.
TS.SM.7.1 Global Average Surface Temperature Change
(Figure SPM.7a) and Global Ocean Surface pH
(Figure SPM.7c)
Step 1 – Analyzed simulations
The simulations considered are annual or monthly mean fields from
different model simulations carried out as part of the CMIP5 project
(when applicable the variable name as given in the CMIP5 archive is
indicated in square brackets). The time series between 1850 and 2005
originate from the historical simulations. The two time series of the
future projections are from RCP2.6 and RCP8.5. The box plots show-
ing the change at the end of the century additionally use RCP4.5 end
RCP6.0. Table TS.SM.1 lists the models and ensemble simulations used
for panels (a) and panel (c). Only one ensemble simulation per model
is used. All models are weighted equally except for sea ice (panel (b))
where a subset of models is considered.
Step 2a – Interpolation
For panel (a), the monthly temperature fields [tas] are re-gridded to a
2.5° × 2.5° grid using bilinear interpolation. No special treatment is
used at the land-sea border.
For panel (c), the monthly temperature [tos] and salinity [sos] fields are
first averaged to yield annual means. Then, annual-mean temperature,
salinity, dissolved inorganic carbon [dissic] and alkalinity [talk] fields
are re-gridded to a 1° × 1° using bilinear interpolation. For the model
MIROC-ESM-CHEM the upper-most layers of the 3-dimensional fields
of monthly sea water potential temperature [thetao] and monthly sea
water salinity [so] are used.
Step 2b – Derivation of pH
For each model, surface pH was computed from simulated DIC, alka-
linity, temperature, and salinity. Before computation each simulated
input field was corrected for its decadal mean bias relative to modern
observations, using the approach of Orr et al. (2005) and Orr (2011).
That is, pH was computed after first removing from each model field,
the average difference between the model mean during 1989–1998
Table TS.SM.1 | Models and ensembles used for panels (a) and (c).
Model Ensemble Member Historical RCP2.6 RCP4.5 RCP6.0 RCP8.5
ACCESS1.0 r1i1p1 (a) (a) (a)
ACCESS1.3 r1i1p1 (a) (a) (a)
BCC-CSM1.1 r1i1p1 (a) (a) (a) (a) (a)
BCC-CSM1.1(m) r1i1p1 (a) (a) (a) (a)
BNU-ESM r1i1p1 (a) (a) (a) (a)
CanESM2 r1i1p1 (a) (c) (a) (c) (a) (c) (a) (c)
CCSM4 r1i1p1 (a) (a) (a) (a) (a)
CESM1(BGC) r1i1p1 (a) (a) (a)
CESM1(CAM5) r1i1p1 (a) (a) (a) (a) (a)
CMCC-CM r1i1p1 (a) (a) (a)
CMCC-CMS r1i1p1 (a) (a) (a)
CNRM-CM5 r1i1p1 (a) (a) (a)
CSIRO-Mk3.6.0 r1i1p1 (a) (a) (a) (a) (a)
EC-EARTH r8i1p1 (a) (a) (a) (a)
(continued on next page)
TSSM
Technical Summary Supplementary Material
TSSM-8
Model Ensemble Member Historical RCP2.6 RCP4.5 RCP6.0 RCP8.5
FGOALS-g2 r1i1p1 (a) (a) (a) (a)
FIO-ESM r1i1p1 (a) (a) (a) (a) (a)
GFDL-CM3 r1i1p1 (a) (a) (a) (a) (a)
GFDL-ESM2G r1i1p1 (a) (c) (a) (c) (a) (c) (a) (c) (a) (c)
GFDL-ESM2M r1i1p1 (a) (c) (a) (c) (a) (c) (a) (c) (a) (c)
GISS-E2-H r1i1p1 (a) (a) (a) (a) (a)
GISS-E2-H r1i1p2 (a) (a) (a) (a) (a)
GISS-E2-H r1i1p3 (a) (a) (a) (a) (a)
GISS-E2-H-CC r1i1p1 (a) (a)
GISS-E2-R r1i1p1 (a) (a) (a) (a) (a)
GISS-E2-R r1i1p2 (a) (a) (a) (a) (a)
GISS-E2-R r1i1p3 (a) (a) (a) (a) (a)
GISS-E2-R-CC r1i1p1 (a) (a)
HadGEM2-AO r1i1p1 (a) (a) (a) (a) (a)
HadGEM2-CC r1i1p1 (a) (c) (a) (c) (a)
HadGEM2-ES r2i1p1 (a) (a) (a) (a) (a)
INM-CM4 r1i1p1 (a) (a) (a)
IPSL-CM5A-LR r1i1p1 (a) (c) (a) (c) (a) (c) (a) (c) (a) (c)
IPSL-CM5A-MR r1i1p1 (a) (c) (a) (c) (a) (c) (a) (a) (c)
IPSL-CM5B-LR r1i1p1 (a) (c) (a) (a) (c)
MIROC5 r1i1p1 (a) (a) (a) (a) (a)
MIROC-ESM r1i1p1 (a) (c) (a) (c) (a) (c) (a) (a) (c)
MIROC-ESM-CHEM r1i1p1 (a) (c) (a) (c) (a) (c) (a) (c) (a) (c)
MPI-ESM-LR r1i1p1 (a) (c) (a) (c) (a) (c) (a) (c)
MPI-ESM-MR r1i1p1 (a) (c) (a) (c) (a) (c) (a) (c)
MRI-CGCM3 r1i1p1 (a) (a) (a) (a) (a)
NorESM1-M r1i1p1 (a) (a) (a) (a) (a)
NorESM1-ME r1i1p1 (a) (c) (a) (a) (c) (a) (a)
Table TS.SM.1 (continued)
and the observational reference. For observed fields, the GLODAP grid-
ded data product (Key et al., 2004) for DIC and alkalinity along with
the 2009 World Ocean Atlas climatology for temperature, salinity, and
concentrations of phosphate and silica (Locarnini et al., 2010; Antonov
et al., 2010; Garcia et al., 2010) were used. Changes to the concentra-
tions of phosphate and silica were assumed to be zero, because not
all models provided those variables. pH was computed using routines
based on the standard OCMIP carbonate chemistry adapted for earlier
studies (Orr, 2011) to compute all carbonate system variables and use
recommended constants from the Guide to Best Practices for Ocean
CO
2
Measurements (Dickson et al., 2007).
Step 3 – Global and annual mean
The monthly (temperature) or annual (pH) surface fields are averaged
(weighted by the cosine of the latitude) to obtain the global mean
values. The monthly global mean temperature values are averaged to
annual means.
Step 4 – Reference period
The average from 1986 to 2005 of the annual means for each model is
computed and is subtracted from the respective model time series to
obtain the corresponding temperature anomalies.
Step 5 – Mean and standard deviation
The mean and standard deviation over all the models is calculated. For
the time period after 2006 all the possible models that are listed in
Table TS.SM.1 are used. If a model provided several RCPs based on the
same historical simulation, that historical simulation is counted only
once.
Step 6 – Uncertainty estimates
First, for each model the average from 2081 to 2100 is computed from
the above mentioned time series. Then, in a second step, the mul-
ti-model average and standard deviation over all model averages are
calculated. The likely ranges on the right of the figure show the mean
plus/minus 1.64 times the standard deviation across the model averag-
es. The shading on the time series indicates the mean value plus/minus
1.64 times the standard deviation across the models for each year.
Step 7 – Graphical display
To close the multi-model mean time series at the year 2005 when the
historical simulation ends and the RCP begins, the value at year 2005
is assigned to belong to both the historical time series and also to the
corresponding RCP.
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TS.SM.7.2 Northern Hemisphere September Sea Ice
Extent – Figure SPM.7b
Step 1 – Analyzed simulations
Table TS.SM.2 provides the model and RIP ensemble member included
from each RCP to create the multi-model mean time series of the NH
September sea ice extent [sic] shown in Figure SPM.7b. In most cases,
the first ensemble member (r1i1p1) was used. A selection algorithm
produces a subset of models that most closely match observations,
and is detailed below. The corresponding historical ensemble member
Model Ensemble Member RCP2.6 Historical/RCP4.5 RCP6.0 RCP8.5
ACCESS1.0 r1i1p1 x x
ACCESS1.3 r1i1p1 x x
BCC-CSM1.1 r1i1p1 x x x x
BCC-CSM1.1(m) r1i1p1 x x x x
BNU-ESM r1i1p1 x x x
CanESM2 r1i1p1 x x x
CCSM4 r1i1p1 x x x x
CESM1(BGC) r1i1p1 x x
CESM1(CAM5) r1i1p1 x x x x
CESM1(WACCM) r2i1p1 x x x
CMCC-CM r1i1p1 x x
CMCC-CMS r1i1p1 x x
CNRM-CM5 r1i1p1 x x x
CSIRO-Mk3.6.0 r1i1p1 x x x x
EC-EARTH r1i1p1 x x
r8i1p1 x
FGOALS-g2 r1i1p1 x x x
FIO-ESM r1i1p1 x x x x
GFDL-CM3 r1i1p1 x x x x
GFDL-ESM2G r1i1p1 x x x x
GFDL-ESM2M r1i1p1 x x x x
GISS-E2-H r1i1p1 x x x x
GISS-E2-H-CC r1i1p1 x
GISS-E2-R r1i1p1 x x x x
GISS-E2-R-CC r1i1p1 x
HadGEM2-AO r1i1p1 x x x x
HadGEM2-CC r1i1p1 x x
HadGEM2-ES r2i1p1 x x x x
INM-CM4 r1i1p1 x x
IPSL-CM5A-LR r1i1p1 x x x x
IPSL-CM5A-MR r1i1p1 x x x x
IPSL-CM5B-LR r1i1p1 x x
MIROC5 r1i1p1 x x x x
MIROC-ESM r1i1p1 x x x x
MIROC-ESM-CHEM r1i1p1 x x x x
MPI-ESM-LR r1i1p1 x x x
MPI-ESM-MR r1i1p1 x x x
MRI-CGCM3 r1i1p1 x x x x
NorESM1-M r1i1p1 x x x x
NorESM1-ME r1i1p1 x x x x
is catenated with the respective RCP scenario ensemble member to
create a continuous time series from 1850–2100.
Step 2 – Time series of NH September sea ice extent
Using the sea ice concentration field, a mask of the sea ice concentra-
tion >15% for each month of data for the Northern Hemisphere was
created. For each month, the sea ice extent is the sum of the area of
the ocean [areacello] times the ocean fraction [sftof] times the mask
of sic >15% at each grid point. The time series are computed on the
original model grids, which is usually the ocean grid. In some cases,
Table TS.SM.2 | Models and ensemble members used.
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Technical Summary Supplementary Material
TSSM-10
sea ice concentration is on the atmospheric grid. In cases where the
grid area was not available for regular grids, a regular lat-lon grid was
constructed based on the grid dimensions following
areacello=((dlat*2π/360)*R_earth) .* ((dlon*2 π/360).*(R_earth*-
cos(LAT))),
with R_earth being the radius of Earth (6,371,000 m), dlat and dlon
being the differentials in lat/lon in each dimension, and LAT being the
latitude in radians.
If the ocean fraction was unavailable, it was assumed that the ocean
fraction was 1 where the sea ice concentration was greater than 0%.
Step 3 – Create multi-model mean time series
The multi-model mean time series of sea ice extent is computed
across all model members in Table TS.SM.2. A five-year running mean
is applied to this time series. This is plotted as the dotted line in the
figure. Some time series start later than 1850 or end earlier than 2100,
and these are treated as missing values for those years.
Step 4 – Select models that most closely match observations
The selection process is done in a series of steps which compare the
models to observed/reanalyzed data. This selection process is based on
the underlying assessment of Chapter 12 and referenced therein. The
method proposed by Massonnet et al. (2012) is applied here to the full
set of models that provided sea ice output fields to the CMIP5 data-
base. For the model selection, all available ensemble members are used
for all of the models that provide simulations for Historical and RCP4.5.
These ensemble members are listed in Table TS.SM.3.
Four diagnostics from the models are compared to the same quantities
in observations or reanalyses. The diagnostics are: (a) September Arctic
sea ice extent (1986–2005), (b) Annual mean Arctic sea ice volume
(1986–2005), (c) Amplitude of the seasonal cycle of Arctic sea ice
extent (1986–2005), and (d) Trend in September Arctic sea ice extent
(1979–2012). Computation of each diagnostic is described and then
the method for comparison is described below.
Step 4a – Computation of diagnostic quantities
(a) Sea ice extent is computed for each model ensemble member as
outlined above to get the total area where sea ice concentration is
>15%. For each ensemble member, an average September sea ice
extent is then computed for the years 1986–2005. Observations for
sea ice extent use the monthly mean sea ice extents from Comiso and
Nishio (2008, updated 2012). The observations were computed in the
same way as in the models (i.e., these are the monthly mean extents
computed from the observed monthly mean sea ice concentration).
(b) Sea ice volume is computed as the sum of the sea ice thickness field
[sit] times the ocean area [areacello] times the ocean fraction [sftof],
since the sea ice thickness is given as thickness averaged over the
entire ocean grid cell. Caveats for the grids are the same as discussed
in Step 2 above. The time series of monthly sea ice volume for each
ensemble member is then annually averaged for the period 1986–
2005. The bias-adjusted PIOMAS (Pan-Arctic Ice-Ocean Modelling and
Assimilation System) reanalysis data (Schweiger et al., 2011) is used
to provide estimates for sea ice volume for comparison to the models.
(c) The amplitude of the seasonal cycle of Arctic sea ice extent is com-
puted for each model from a climatology of monthly sea ice extent
for 1986–2005. The amplitude is the difference between the maximum
(March) and minimum (September) sea ice extent for each model
ensemble member. Amplitude of seasonal cycle for observations are
computed in the same way from Comiso and Nishio (2008, updated
2012).
(d) The linear trend in September sea ice extent is computed for the
period 1979–2012. Again observations are taken from Comiso and
Nishio (2008, updated 2012).
Step 4b – Estimation of natural variability for model ensembles
For models with multiple ensemble members, a standard deviation
is computed for each of the diagnostics for each ensemble member.
Then the mean of all the standard deviations is computed, and using
this value, a ±2 standard deviation interval is constructed around the
ensemble mean or single realization of each diagnostic for each model.
Step 4c – Model selection - Comparison of modeled diagnostics
to observed/reanalyzed diagnostic
For each of the observed/reanalyzed diagnostics, a ±–20% interval is
constructed around the mean value for the given period. A model is
retained in the selection if, for each diagnostic, either the ±2 standard
deviation around the model ensemble mean diagnostic overlaps the
±20% interval around the observed/reanalysed value of the diagnostic
OR at least one ensemble member from that model gives a value for
the diagnostic that falls within ±20% of the observed/reanalysed data.
A model is selected only if all four diagnostic values meet this criterion.
Results of the selection
The model diagnostics are calculated using RCP4.5 which has the
largest number of models. Five models are selected by this process:
ACCESS1.0, ACCESS1.3, GFDL-CM3, IPSL-CM5A-MR, MPI-ESM-MR,
and all five models have simulations for both RCP8.5 and RCP4.5. For
RCP2.6 only three of this subset have simulations (GFDL-CM3, IPSL-
CM5A-MR, MPI-ESM-MR), and for RCP6.0, only two models have sim-
ulations (GFDL-CM3, IPSL-CM5A-MR).
Step 5 – Time series of sea ice extent for the selected models
The multi-model mean time series of September sea ice extent is cal-
culated for the selected models. The solid line shows the multi-model
mean smoothed with a five-year running mean, and the shading rep-
resents the minimum and maximum range of the selected model time
series, also smoothed by the same five year running mean.
The shaded bars on the right are the multi-model mean and the mean
of the maximum and minimum range for the selected models for the
period 2081–2100.
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Technical Summary Supplementary Material
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Model Ensemble Member RCP4.5
ACCESS1.0 r1i1p1
ACCESS1.3 r1i1p1
BCC-CSM1.1 r1i1p1
BCC-CSM1.1(m) r1i1p1
BNU-ESM r1i1p1
CanESM2 r1i1p1
r2i1p1
r3i1p1
r4i1p1
r5i1p1
CCSM4 r1i1p1
r2i1p1
r3i1p1
r4i1p1
r5i1p1
r6i1p1
CESM1(BGC) r1i1p1
CESM1(CAM5) r1i1p1
r2i1p1
r3i1p1
CESM1(WACCM) r2i1p1
CMCC-CM r1i1p1
CMCC-CMS r1i1p1
CNRM-CM5 r1i1p1
CSIRO-Mk3.6.0 r1i1p1
r2i1p1
r3i1p1
r4i1p1
r5i1p1
r6i1p1
r7i1p1
r8i1p1
r9i1p1
10i1p1
EC-EARTH r1i1p1
r2i1p1
r3i1p1
r6i1p1
r7i1p1
r8i1p1
r9i1p1
10i1p1
11i1p1
12i1p1
13i1p1
14i1p1
FGOALS-g2 r1i1p1
FIO-ESM r1i1p1
r2i1p1
r3i1p1
GFDL-CM3 r1i1p1
r3i1p1
r5i1p1
GFDL-ESM2G r1i1p1
GFDL-ESM2M r1i1p1
GISS-E2-H r1i1p1
r2i1p1
r3i1p1
r4i1p1
r5i1p1
GISS-E2-H-CC r1i1p1
Model Ensemble Member RCP4.5
GISS-E2-R r1i1p1
r2i1p1
r3i1p1
r4i1p1
r5i1p1
r6i1p1
GISS-E2-R-CC r1i1p1
HadGEM2-AO r1i1p1
HadGEM2-CC r1i1p1
HadGEM2-ES r2i1p1
r3i1p1
r4i1p1
INM-CM4 r1i1p1
IPSL-CM5A-LR r1i1p1
r2i1p1
r3i1p1
r4i1p1
IPSL-CM5A-MR r1i1p1
IPSL-CM5B-LR r1i1p1
MIROC5 r1i1p1
r2i1p1
r3i1p1
MIROC-ESM r1i1p1
MIROC-ESM-CHEM r1i1p1
MPI-ESM-LR r1i1p1
r2i1p1
r3i1p1
MPI-ESM-MR r1i1p1
r2i1p1
r3i1p1
MRI-CGCM3 r1i1p1
NorESM1-M r1i1p1
NorESM1-ME r1i1p1
Table TS.SM.3 | Models and ensembles used for model selection, RCP4.5.
TS.SM.8 Notes and Technical Details on Maps
Showing CMIP5 Results in the Summary
for Policymakers – Figure SPM.8
This material documents the provenance of the data and plotting
procedures that were used to create Figure SPM.8, based on CMIP5
model results as of March, 2013. This figure is closely derived from Fig-
ures12.11 and TS.15 (global average surface temperature), TS.16 (pre-
cipitation), 12.29 and TS.17 (sea ice), 6.28 and TS.20b (ocean surface
pH), but includes fewer model scenarios. The reader is referred to the
Technical Summary or the Chapters 12 and 6 where all RCP scenarios
are given for the respective quantity.
TS.SM.8.1 Change in Average Surface Temperature
(Figure SPM.8a) and Change in Average
Precipitation (Figure SPM.8b)
Step 1 – Analyzed simulations
The simulations considered are monthly mean fields of surface tem-
perature [tas] and precipitation [pr] from different model simulations
carried out as part of the CMIP5 project (when applicable the variable
name as given in the CMIP5 archive is indicated in square brackets).
Table TS.SM.4 lists the models and ensemble members used for these
panels. Only one ensemble member per model is used.
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Step 2 – Interpolation
In a first step the monthly fields are re-gridded to a 2.5° × 2.5° grid
using bilinear interpolation. No special treatment is used at the land-
sea border.
Table TS.SM.4 | Models and ensemble members used.
Model Ensemble Member RCP2.6 Historical/RCP4.5 RCP6.0 RCP8.5
ACCESS1.0 r1i1p1 x x
ACCESS1.3 r1i1p1 x x
BCC-CSM1.1 r1i1p1 x x x x
BCC-CSM1.1(m) r1i1p1 x x x
BNU-ESM r1i1p1 x x x
CanESM2 r1i1p1 x x x
CCSM4 r1i1p1 x x x x
CESM1(BGC) r1i1p1 x x
CESM1(CAM5) r1i1p1 x x x x
CMCC-CM r1i1p1 x x
CMCC-CMS r1i1p1 x x
CNRM-CM5 r1i1p1 x x
CSIRO-Mk3.6.0 r1i1p1 x x x x
EC-EARTH r8i1p1 x x x
FGOALS-g2 r1i1p1 x x x
FIO-ESM r1i1p1 x x x x
GFDL-CM3 r1i1p1 x x x x
GFDL-ESM2G r1i1p1 x x x x
GFDL-ESM2M r1i1p1 x x x
GISS-E2-H r1i1p1 x x x x
GISS-E2-H r1i1p2 x x x x
GISS-E2-H r1i1p3 x x x x
GISS-E2-H-CC r1i1p1 x
GISS-E2-R r1i1p1 x x x x
GISS-E2-R r1i1p2 x x x x
GISS-E2-R r1i1p3 x x x x
GISS-E2-R-CC r1i1p1 x
HadGEM2-AO r1i1p1 x x x x
HadGEM2-CC r1i1p1 x x
HadGEM2-ES r2i1p1 x x x x
INM-CM4 r1i1p1 x x
IPSL-CM5A-LR r1i1p1 x x x x
IPSL-CM5A-MR r1i1p1 x x x x
IPSL-CM5B-LR r1i1p1 x x
MIROC5 r1i1p1 x x x x
MIROC-ESM r1i1p1 x x x x
MIROC-ESM-CHEM r1i1p1 x x x x
MPI-ESM-LR r1i1p1 x x x
MPI-ESM-MR r1i1p1 x x x
MRI-CGCM3 r1i1p1 x x x x
NorESM1-M r1i1p1 x x x x
NorESM1-ME r1i1p1 x x x x
Step 3 – Annual average and period
The monthly mean values are averaged to annual means. Then in a
second step the time mean is computed over the 20-year period of
interest.
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TSSM-13
Step 4 – Time average and anomalies
The average from 1986 to 2005 of the annual means for each model
is computed as the reference value and the annual mean from 2081 to
2100 are computed as the future period for the two RCPs. For each model
the reference value is then subtracted from the future period value.
Step 5 – Calculation of the significance
Step 5a – Natural variability
To compute the natural variability all the models that provide more
than 500 years of pre-industrial control simulation [piControl] are
used. A list of these models is given in Table TS.SM.5. For each model
the first 100 years are discarded to minimize problems with model
initialization. Re-gridding and calculation of annual means is done as
described in steps 2 and 3. The control runs are divided into 20-year
non-overlapping periods. If the available data are not a multiple of
20-year the remaining years after the last 20-year period are not used
in the calculation.
Averages over the 20-year periods are computed for every grid point.
A quadratic trend is subtracted from this time series of 20-year aver-
aged periods to remove potential model drift at each grid point. Finally
Model Ensemble Member
ACCESS1.0 r1i1p1
ACCESS1.3 r1i1p1
BCC-CSM1.1 r1i1p1
BNU-ESM r1i1p1
CanESM2 r1i1p1
CCSM4 r1i1p1
CESM1(BGC) r1i1p1
CMCC-CMS r1i1p1
CNRM-CM5 r1i1p1
CSIRO-Mk3-6-0 r1i1p1
FGOALS-g2 r1i1p1
FIO-ESM r1i1p1
GFDL-CM3 r1i1p1
GFDL-ESM2G r1i1p1
GFDL-ESM2M r1i1p1
GISS-E2-H r1i1p2
GISS-E2-H r1i1p3
GISS-E2-R r1i1p2
GISS-E2-R r1i1p3
INM-CM4 r1i1p1
IPSL-CM5A-LR r1i1p1
MIROC5 r1i1p1
MIROC-ESM r1i1p1
MPI-ESM-LR r1i1p1
MPI-ESM-MR r1i1p1
MPI-ESM-P r1i1p1
MRI-CGCM3 r1i1p1
NorESM1-M r1i1p1
Table TS.SM.5 | Models and ensemble members from the piControl experiments used
for the calculation of the natural variability.
for each model the standard deviation is computed over the different
20-year periods and for each grid point.
To obtain the final value of the natural variability the median of the
standard deviations of the different models is multiplied with the
square root of 2 (the natural variability characterizes the typical dif-
ference between two 20-year periods, rather than the difference of
one period from the long-term mean, the former being larger than the
latter by the square root of two).
Step 5b – Testing for significance
For each model the projected change is taken relative to its reference
period and then the multi-model average at every grid point is com-
puted. In a second step, at each grid point the number of models with
positive and negative change are counted.
If more than 90% of the models agree on the sign of the change and
the multi-model mean change is larger than 2 times the natural var-
iability (as defined above) this grid point is said to be significant and
robust across models.
Step 5c – Check for non-significance
Again, for each model the projected change is taken relative to the
reference period and then the multi-model average at every grid point
is computed.
If the multi-model mean change at one grid point is less than the natu-
ral variability (as defined above) the value is said to be non-significant.
Step 6 – Graphical display
For each model the projected change is taken relative to the reference
period and then the multi-model average at every grid point is comput-
ed. The locations that are significant and robust (as described in step
5b) are marked by small black dots and the locations that are non-sig-
nificant (as described in step 5c) are marked by hatching.
For panel b, all calculations are performed as absolute changes. To
show the relative changes, the multi-model mean precipitation change
is divided by the multi-model mean of the reference period.
TS.SM.8.2 Northern Hemisphere September Sea Ice
Extent (Figure SPM.8c)
Step 1 – Analyzed simulations and subset of models
The simulations analyzed here are the same as those listed for Figure
SPM.7b. The subset of models are the same that are selected for Figure
SPM.7b outlined in the following Step 4. Only one ensemble member
from each model is used to create these figures.
Step 2 – Computation of mean sea ice concentration
For each model ensemble member, the mean sea ice concentration [sic]
is calculated for the two periods, 1986–2005 and 2081–2100, on the
native model grid (see also recipe for Figure SPM.7b).
Step 3 – Regrid sea ice concentration to common grid
SOSIE (http://sosie.sourceforge.net/) is used to regrid the mean sea
ice concentration to a common 1° × 1° grid, applying the bilinear
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TSSM-14
interpolation scheme (SOSIE: cmethod = ‘bilin’). Further, the regridded
sea ice concentrations are ‘drowned’ across the land-sea boundary to
eliminate low-biased interpolated values in the area of land-sea tran-
sition (SOSIE: ldrown = T). With this approach, interpolation artifacts
can occur throughout the Canadian Archipelago, since each model rep-
resents this area quite differently. Comparison of individual models on
their native grid allows to identify and mask such areas. Note that, for
these reasons the interpolated sea ice concentrations shall not be used
for quantitative interpretation, but only for visualization purposes. For
visualization the MATLAB land-ocean mask is overlaid.
Step 4 – Calculate multi-model mean sea ice concentration
For each RCP, RCP2.6 and RCP8.5, and each period, 1986–2005 and
2081–2100, the mean sea ice concentration is calculated in each grid
cell on the common grid. The same is done for the subset of models
for each period. For RCP2.6 this subset is GFDL-CM3, IPSL-CM5A-MR,
MPI-ESM-MR. For RCP8.5 this subset is ACCESS1.0, ACCESS1.3, GFDL-
CM3, IPSL-CM5A-MR, MPI-ESM-MR.
Step 5 – Contour the multi-model mean sea ice concentration
of 15%
The multi-model mean sea ice concentration is contoured at 15%
according to the following:
1986–2005: multi-model mean all models: white line
1986–2005: subset models: light blue line
2081–2100: multi-model mean all models: white filled patch
2081–2100: subset models: light blue filled patch
Note for RCP8.5 there is no sea ice concentration >15% for the subset
of models.
The decision was taken to contour the 15% contour of mean sea ice
concentration to make this figure consistent with Figure 12.29, which
shows a contour plot of the multi-model mean sea ice concentrations.
It is also possible to make binary fields of sea ice concentration >15%,
take the mean of those binary fields (for both 20 year averages and
then in multi-model averages), and contour the 50% contour of the
mean binary field as the mean sea ice extent. This option was not
chosen here.
Model Ensemble Member Historical RCP2.6 RCP4.5 RCP6.0 RCP8.5
CanESM2 r1i1p1 d d d d
GFDL-ESM2G r1i1p1 d d d d d
GFDL-ESM2M r1i1p1 d d d d d
HadGEM2-CC r1i1p1 d d d
IPSL-CM5A-LR r1i1p1 d d d d d
IPSL-CM5A-MR r1i1p1 d d d d
IPSL-CM5B-LR r1i1p1 d d d
MIROC-ESM r1i1p1 d d d d d
MIROC-ESM-CHEM r1i1p1 d d d d d
MPI-ESM-LR r1i1p1 d d d d
MPI-ESM-MR r1i1p1 d d d d
NorESM1-ME r1i1p1 d d
Table TS.SM.6 | Models and ensemble members used.
TS.SM.8.3 Change in Ocean Surface pH (Figure SPM.8d)
Step 1 – Analyzed simulations
The simulations considered are annual or monthly mean fields from
different model simulations carried out as part of the CMIP5 project
(when applicable the variable name as given in the CMIP5 archive
is indicated in square brackets). Table TS.SM.6 lists the models and
ensemble members used for these panels. Only one ensemble member
per model is used.
Step 2a – Interpolation
In a first step, the monthly temperature [tos] and salinity [sos] fields
are first averaged to yield annual means. For the model MIROC-ESM-
CHEM the upper-most layer of the 3-dimensional fields of monthly sea
water potential temperature [thetao] and monthly sea water salinity
[so] are used. Then, annual-mean temperature, salinity, dissolved inor-
ganic carbon [dissic] and alkalinity [talk] fields are re-gridded to a 1° ×
1° using bilinear interpolation.
Step 2b – Derivation of pH
For each model, surface pH was computed from simulated DIC, alkalini-
ty, temperature, and salinity. Before computation each simulated input
field was corrected for its decadal mean bias relative to modern obser-
vations, using the approach used in Orr et al. (2005) and Orr (2011).
That is, pH was computed after first removing from each model field,
the average difference between the model mean during 1989–1998
and the observational reference. For observed fields, we used the
GLODAP gridded data product (Key et al., 2004) for DIC and alkalinity
along with the 2009 World Ocean Atlas climatology for temperature,
salinity, and concentrations of phosphate and silica (Locarnini et al.,
2010; Antonov et al., 2010; Garcia et al., 2010). Changes to the con-
centrations of phosphate and silica were assumed to be zero, because
all models did not provide those variables. pH was computed using
routines based on the standard OCMIP carbonate chemistry adapted
for earlier studies (Orr, 2011) to compute all carbonate system varia-
bles and use recommended constants from the Guide to Best Practices
for Ocean CO
2
Measurements (Dickson et al., 2007).
Step 3 – Average of 20-year period
The time mean is computed over the 20-year period of interest.
TSSM
Technical Summary Supplementary Material
TSSM-15
Step 4 – Time average and anomalies
The average from 1986 to 2005 of the annual means for each model
is computed as the reference value and the annual mean from 2081
to 2100 is computed as the future period for the two RCPs. For each
model the reference value is then subtracted.
Step 5 – Graphical display
For each model the projected change is taken relative to the reference
period and the multi-model mean at every grid point is computed.
TS.SM.9 Notes and Technical Details on the Sea
Level Projection Figure for the Summary
for Policymakers – Figure SPM.9
A full and comprehensive description of the methods used in the pro-
jections of global mean sea level for the 21st century is provided in the
Supplementary Material to Chapter 13 (see Section 13.SM.1). Further
plotting details used to produce Figure SPM.9, and the related Figure
TS.22 are provided here.
TS.SM.9.1 Projected Global Mean Sea Level Rise
Projections are given from process-based models of global mean
sea level rise relative to 1986–2005 for the four emissions scenarios
RCP2.6, RCP4.5, RCP6.0 and RCP8.5.
The likely range for each RCP timeseries is delimited by the data in files
rcpXX_sumlower and rcpXX_sumupper, while the median timeseries
is the data in file rcpXX_summid, where ‘XX’ stands for the respective
RCP scenario. These data files are available from the WGI AR5 website
www.climatechange2013.org. The coloured vertical bars with horizon-
tal lines for the four RCP scenarios indicate the likely ranges and medi-
ans for these scenarios as given in Table 13.5 of Chapter 13.
Note that in Figure SPM.9, projected time series are shown only for
RCP2.6 and RCP8.5. Figure TS.22 include time series for all four RCP
scenarios.
Projected contributions to sea level rise in 2081–2100 relative to
1986–2005 for the four RCP scenarios are provided in Figure TS.21.
TS.SM.10 Notes and Technical Details on the
Summary for Policymakers Figure
Plotting Global Mean Temperature
Increase as a Function of Cumulative
Total Global CO
2
Emissions – Figure
SPM.10
Figure SPM.10 contains data from CO
2
only simulations and the RCP
simulations. This figure is closely derived from TS TFE.8, Figure 1. CO
2
only simulations are represented by grey-shaded patches and thin
black lines, RCP data by coloured lines and patches. CMIP5 results are
taken from the archive as of March 15, 2013. Note that the thick black
line represents the historical time period of the RCP runs.
TS.SM.10.1 Part A – CO
2
Only Runs
The thin black line represents the multi-model mean of the decadal
averaged global-mean temperature response of the models listed in
Table TS.SM.7 to a global 1% CO
2
only forcing increase as performed
as part of CMIP5, as a function of the decadal averaged global-mean
diagnosed carbon emissions.
The dark grey patch represents the 90% range surrounding the dec-
adal averaged model response of the CMIP5 models listed in Table
TS.SM.7 and is calculated as follows: Diagnosed carbon emissions and
temperature response data of the above-defined CMIP5 models (com-
puted as in Gillett et al., 2013) is scaled, respectively, by dividing by the
standard deviation over all available decadal-averaged data points for
a specific scenario. The 90% range is computed in polar coordinates.
The radius stretches along the x-axis (cumulative emissions) and the
angle is the one between the slope from (0, 0) to a respective scaled
point (cumulative emissions, temperature anomaly) and the x-axis. For
each scaled point the radius and angle are computed. A number of
n (n = 20) segments are defined by regularly spaced steps along the
maximum radius of all available decadal-averaged data points of a
specific scenario (scaled as described earlier). From all points that fall
within the boundaries of each respective radius segment, the 5th and
95th percentiles in terms of available angles is computed. These per-
centiles are then assigned to the radius corresponding to the middle
of the current radius segment. Each of these mid-segment radii and its
corresponding pair of angles are then transformed back to Cartesian
coordinates. Finally, the 90% range is drawn by connecting all 5th and
95th percentile points of a specific scenario in a hull.
Model Ensemble Member
GFDL-ESM2G r1i1p1
INM-CM4 r1i1p1
GFDL-ESM2M r1i1p1
IPSL-CM5B-LR r1i1p1
BCC-CSM1.1 r1i1p1
MPI-ESM-MR r1i1p1
IPSL-CM5A-MR r1i1p1
IPSL-CM5A-LR r1i1p1
MPI-ESM-LR r1i1p1
NorESM1-ME r1i1p1
CESM1(BGC) r1i1p1
HadGEM2-ES r1i1p1
MIROC-ESM r1i1p1
CanESM2 r1i1p1
BNU-ESM r1i1p1
Table TS.SM.7 | Models that were included in the shown results of the CO2 only 1%
increase CMIP5 runs (dark grey patch and thin black line).
TSSM
Technical Summary Supplementary Material
TSSM-16
TS.SM.10.2 Part B – RCP Runs
Data of the RCP runs (coloured lines and patches) is prepared with
the same methodology as the data for the CO
2
only runs as described
in the previous section. Note that markers show decadal time steps,
and that the labels in Figure SPM.10 (and TS TFE.8, Figure 1) denote
the cumulative global carbon emissions from 1870 until (but not
including) that year (i.e., label 2050 is placed next to the marker of the
2040–2049 decade). The 90% range is computed for n (n = 12) regu-
larly spaced steps along the maximum radius available for each RCP
(scaled as described earlier). Available Earth System Models (ESM) for
the respective RCP are listed in Table TS.SM.8, available Earth System
Models of Intermediate Complexity (EMIC) in Table TS.SM.9.
Following operations are carried out onto the data:
Decadal means of global-mean temperature change are computed
relative to the 1861–1880 base period.
Emissions from the ESMs for the different scenarios are computed
as in Jones et al. (2013).
Model Ensemble Member RCP2.6 RCP4.5 RCP6.0 RCP8.5
BCC-CSM1.1 r1i1p1 x* x* x* x*
CanESM2 r1i1p1 x x x
CESM1(BGC) r1i1p1 x x
GFDL-ESM2G r1i1p1 x x x x
GFDL-ESM2M r1i1p1 x x x x
HadGEM2-CC r1i1p1 x x
HadGEM2-ES r2i1p1 x x x x
INM-CM4 r1i1p1 x* x*
IPSL-CM5A-LR r1i1p1 x x x x
IPSL-CM5A-MR r1i1p1 x x x
IPSL-CM5B-LR r1i1p1 x x
MIROC-ESM r1i1p1 x x x x
MIROC-ESM-CHEM r1i1p1 x x x x
MPI-ESM-LR r1i1p1 x x x
NorESM1-ME r1i1p1 x x x x
• Land-use change emission estimated for each RCP are added to
all EMICs, and to the ESMs that diagnose fossil-fuel emission only
(see Table TS.SM.8). Land-use change emissions are obtained from
http://www.pik-potsdam.de/~mmalte/rcps/ for each RCP, respec-
tively. Note that the data for Figure SPM.10 provided at the exter-
nal sources cited above may be subject to changes in the future by
the owners. Furthermore, no guarantee is provided that the web-
links cited above remain active.
Decadal-mean cumulative emissions are computed from cumula-
tive carbon emissions relative to 1870.
Each RCP range is drawn as long as data is available for all models
or until temperatures have peaked. The encompassing range shown
in Figure SPM.10 (and TS TFE.8, Figure 1) is constructed by con-
necting the outer last points of each single RCP range and is filled
as long as data are available for all models for RCP8.5. Beyond
this point, the range is illustratively extended by further progressing
along the radius while keeping the angles fixed at those available
at the last point with data from all models for RCP8.5. The fading
out of the range is illustrative.
Model RCP2.6 RCP4.5 RCP6.0 RCP8.5
Bern3D x x x x
DCESS x x x x
GENIE x x x x
IGSM x x x x
UVic x x x x
Table TS.SM.8 | Overview of RCP model runs available in the CMIP5 archive, as used in Figure SPM.10 (and TS TFE.8, Figure 1).
Table TS.SM.9 | Overview of EMIC RCP model runs from (Eby et al. 2013; Zickfeld et al. 2013), as used in Figure SPM.10 (and TS TFE.8, Figure 1). EMICs output is available from
http://www.climate.uvic.ca/EMICAR5.
Notes:
* runs do not include explicit land-use change modelling. Models diagnose fossil-fuel and land-use change emissions jointly and therefore do not require adding land-use change emissions.
TSSM
Technical Summary Supplementary Material
TSSM-17
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Please note that all external web-links cited in this document were active at the time
of publication, but no guarantee is provided that these links remain active.