Editing IPCC:AR6/SROCC/Chapter-4 (section)

===== 4.2.3.3.4 Recent probabilistic and semi-empirical projections =====

A wide range of probabilistic sea level projections exist, ranging from simple scaling relations to partly process-based components combined with scaling relations. Table 4.5 illustrates the overlap between many of the studies, a complete overview is presented by Garner et al. (2017) , and differences between different classes of models are discussed in Horton et al. (2018) <sup>[[#fn:r692|692]]</sup> . Many studies rely on CMIP simulations for an important part of their sea level components. The largest difference can be found in the treatment of the ice dynamics, particularly for Antarctica, which are usually not CMIP5 based. Instead, each derives from one of several estimates of the Antarctic contribution. These results are useful for the purposes of elucidating sensitivities of process-based studies and effects of changing components to the total projection. This report relies on the Antarctic component from Section 4.2.3.2 for calculating the ''likely'' range of RSL. Hence the values in Table 4.5 are not used for the final assessment of RSL including the SROCC specific Antarctic contribution presented in Section 4.2.3.2. Comparing the probabilistic projections (Table 4.6) is difficult because of the subtle differences between their assumptions. Nevertheless, values range much more for 2100 than for 2050.

<span id="table-4.5"></span>
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'''Table 4.5'''

'''Table 4.5:''' Sources of Information Underlying Probabilistic Projections of Sea level Rise (SLR) Projections.

CMIP5 is Coupled Model Intercomparison Project Phase 5, GRD is gravitational, rotational and deformation effects, SMB is surface mass balance, AR4 is IPCC 4th Assessment Report, VLM is vertical land motion, GIA is glacio-isostatic adjustment.

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{| class="wikitable"
|-
| Study
| Thermal expansion
| Glaciers
| Land water storage
| Ice Sheets
| Dynamic sea level
| GRD
| VLM
|-
| Perrette et al. (2013)
| CMIP5
| Global SMB sensitivity and exponent from AR4; total glacier volume from Radić and Hock (2010)
| Not included
| Greenland’s SMB from AR4; semi-empirical model using historical observations.
| CMIP5
| Bamber et al. (2009)
| Not included
|-
| Grinsted et al. (2015)
| CMIP5
| Church et al. (2013)
| Wada et al. (2012)
| Church et al. (2013); Expert elicitation from Bamber and Aspinall (2013)
| CMIP5
| Bamber et al. (2009)
| GIA projections from Hill et al. (2010) using observations
|-
| Slangen et al. (2014a)
| CMIP5
| CMIP5; glacier area inventory Radić and Hock (2010) in a glacier mass loss model
| Wada et al. (2012)
| SMB Meehl et al. (2007), ice dynamics Meehl et al. (2007) and Katsman et al. (2011)
| CMIP5
| Slangen et al. (2014a)
| GIA resulting of ice sheet melt from glacier mass loss model
|-
| Kopp et al. (2014)
| CMIP5
| CMIP5; Marzeion et al. (2012)
| Chambers et al. (2017); Konikow (2011)
| Church et al. (2013); Expert elicitation from Bamber and Aspinall (2013)
| CMIP5
| Mitrovica et al. (2011)
| GIA, tectonics, and subsidence from Kopp et al. (2013)
|-
| Kopp et al. (2017)
| CMIP5
| CMIP5; Marzeion et al. (2012)
| Chambers et al. (2017); Konikow (2011)
| DeConto and Pollard (2016)
| CMIP5
| Mitrovica et al. (2011)
| GIA, tectonics, and subsidence from Kopp et al. (2013)
|-
| Le Bars et al. (2017)
| CMIP5
| Four glacier models:
Giesen and Oerlemans (2013)

Marzeion et al. (2012),

Radić et al. (2014)

Slangen and Van de Wal (2011)

| Wada et al. (2012)
| DeConto and Pollard (2016);
Fettweis et al. (2013)

Church et al. (2013)

| CMIP5
| –
|-
| Jackson and Jevrejeva (2016)
| CMIP5
| Marzeion et al. (2012)
| Wada et al. (2012)
| Church et al. (2013); Expert elicitation from Bamber and Aspinall (2013)
| CMIP5
| Bamber et al. (2009)
| GIA resulting of ice sheet melt from glacier mass loss model Peltier et al. (2015)
|-
| de Winter et al. (2017)
| CMIP5
| CMIP5; glacier area inventory Radić and Hock (2010) in a glacier mass loss model
| Wada et al. (2012)
| Church et al. (2013); Expert elicitation de Vries and van de Wal (2015); Ritz et al. (2015)
| CMIP5
| Mitrovica et al. (2001)
| GIA resulting of ice sheet melt from glacier mass loss model
|}
<!-- END TABLE -->

<span id="table-4.6"></span>
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'''Table 4.6:'''

'''Table 4.6:''' Median and ''likely'' Global Mean Sea Level (GMSL) rise projections (m). Values between brackets are ''likely'' range, if no values are given the ''likely'' range is not available. The table shows result from the probabilistic and semi-empirical results. A is 2000 as base line year up to 2100; B is the average of 1986–2005 as base line for the projection up to 2081–2100, C 1980–1999 as baseline up to 2090–2099.

<!-- TABLE -->
{| class="wikitable"
|-
|
| colspan="3"| 2050
| colspan="3"| 2100
|-
|
| Period
| RCP2.6
| RCP4.5
| RCP8.5
| RCP2.6
| RCP4.5
| RCP8.5
|-
| Perrette et al. (2013)
| C
|
| 0.28
(0.23–0.32)

| 0.28
(0.23–0.34)

|
| 0.86
(0.66–1.11)

| 1.06
(0.78–1.43)

|-
| Grinsted et al. (2015)
| A
|
| 0.8
(0.58–1.20)

|-
| Slangen et al. (2014a) ''' '''
| B AB B
|
| 0.54
(0.35–0.73)

| 0.71
(0.43–0.99)

|-
| Kopp et al. (2014)
| A
| 0.25
(0.21–0.29)

| 0.26
(0.21–0.31)

| 0.29
(0.24–0.34)

| 0.50
(0.37–0.65)

| 0.59
(0.45–0.77)

| 0.79
(0.62–1.00)

|-
| Kopp et al. (2017)
| A
| 0.23
(0.16–0.33)

| 0.26
(0.18–0.36)

| 0.31
(0.22–0.40)

| 0.56
(0.37–0.78)

| 0.91
(0.66–1.25)

| 1.46
(1.09–2.09)

|-
| de Winter et al. (2017)
| B
|
| 0.68/0.86
|-
| Jackson and Jevrejeva (2016)
| B
|
| 0.54
(0.36–0.72)

| 0.75
(0.54–0.98)

|-
| Le Bars et al. (2017)
| B
|
| 1.06
(0.65-1.47)

| 1.84
(1.24-2.46)

|-
| Nauels et al. (2017b)
| B
| 0.24
(0.19–0.30)

| 0.25
(0.21–0.30)

| 0.27
(0.23–0.33)

| 0.45
(0.35–0.56)

| 0.55
(0.45–0.67)

| 0.79
(0.65–0.97)

|-
| Bakker et al. (2017)
| A
| 0.20
| 0.23
| 0.25
| 0.53
| 0.72
| 1.16
|-
| Wong et al. (2017)
| A
| 0.26
| 0.28
| 0.30
| 0.55
| 0.77
| 1.50
|-
| Jevrejeva et al. (2014a)
| A
|
| 0.80
(0.6-1.2)

|-
| Schaeffer et al. (2012)
| A
|
| 0.90
| 1.02
|-
| Mengel et al. (2016)
| B
| 0.18
| 0.21
| 0.39
| 0.53
| 0.85
|}
<!-- END TABLE -->

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