Articles | Volume 13, issue 1
© Author(s) 2022. This work is distributed underthe Creative Commons Attribution 4.0 License.
The Mediterranean climate change hotspot in the CMIP5 and CMIP6 projections
- Final revised paper (published on 08 Feb 2022)
- Supplement to the final revised paper
- Preprint (discussion started on 30 Jul 2021)
- Supplement to the preprint
Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor |
: Report abuse
RC1: 'Comment on esd-2021-65', Anonymous Referee #1, 16 Aug 2021
- AC1: 'Reply on RC1', Josep Cos, 22 Oct 2021
RC2: 'Comment on esd-2021-65', Anonymous Referee #2, 02 Sep 2021
- AC2: 'Reply on RC2', Josep Cos, 22 Oct 2021
RC3: 'Comment on esd-2021-65', Anonymous Referee #3, 24 Sep 2021
- AC3: 'Reply on RC3', Josep Cos, 22 Oct 2021
Peer review completion
AR: Author's response | RR: Referee report | ED: Editor decision
ED: Reconsider after major revisions (23 Oct 2021) by Gabriele Messori
AR by Josep Cos on behalf of the Authors (04 Dec 2021)  Author's response Author's tracked changes Manuscript
ED: Referee Nomination & Report Request started (06 Dec 2021) by Gabriele Messori
RR by Anonymous Referee #2 (07 Dec 2021)
RR by Anonymous Referee #1 (11 Dec 2021)
ED: Publish subject to minor revisions (review by editor) (16 Dec 2021) by Gabriele Messori
AR by Josep Cos on behalf of the Authors (22 Dec 2021)  Author's response Author's tracked changes Manuscript
ED: Publish subject to technical corrections (03 Jan 2022) by Gabriele Messori
AR by Josep Cos on behalf of the Authors (11 Jan 2022)  Author's response Manuscript
The Mediterranean region is an important climate change hotspot due to pronounced warming and drying projected under future greenhouse gas emission scenarios. This article analyses and compares output from CMIP5 and the recent CMIP6 over the region. Its results provide a useful update on Mediterranean projections. Several methodological points require some clarification or slight modification, however.
Also, what observational reference do you choose (in DIFF)? The mean calculated over all observation/reanalysis products?
l.1 “increased warming trend” -> maybe “enhanced warming trend”?
l.1 “makes” -> “make”
l.2 “historical and scenario” -> missing “future”?
l.4 “following scenarios RCP2.6, SSP1-2.6, RCP4.5, SSP2-4.5, RCP8.5 and SSP5-8.5” -> I suggest separating the CMIP5 and the CMIP6 scenarios
l.7 “along” -> “over” (and “over” on l. 8 can become “across” or “during”)
l.9 “being CMIP6” -> “CMIP6 being”
l.17 “continental” -> “oceanic” as well. A continental climate is not “humid and mild”.
ll.17-19 This sentence is unclear. Can you please rephrase?
l.24 “global warming mean” -> “global-mean warming”
l.26 add “are” before “projected”
ll.26-28 Unclear what this sentence refers to here…
l.37 “tools” -> you mean GCMs?
l.59 “assumption” -> “criteria”?
l.62 “presented in section 3”
l.69 It is not just PSL that is used to calculate model weights; TAS is used also, correct?
l.82 “has” -> “have”
l.89 “initial conditions” (no “-“)
l.96 “containing” -> “including”
l.106 “differences in the thermodynamic properties of the surfaces” -> “differences in surface thermodynamic properties”
Figure 1 -> it would be useful to have also the numerical values for the global/latitudinal mean changes
Table 1. -> Please specify in the caption the variables corresponding to the acronyms (TAS, PR, etc.), or specify later at l.104 when the variables are introduced.
l.145 Did you introduce variable M?
l.149 “weight” -> “more weight”?
l.167 “30-45N latitudinal belt mean” -> Why not all land regions? One could argue that to make it a global hotspot one should compare against all other land areas (say of the same size). One issue also is that both the Mediterranean and the 30-45N belt contain many grid points with very small precipitation averages -> potentially large relative changes which may bias the analysis.
Also, you compare to 30-45N values but only over land, right? In that case Figure S3 should not have data over the oceans. For the sake of readers who are not used to land-only values (“global” often means land and ocean), I suggest you specify “global land mean”, e.g., at l.166.
l.176 “projects larger precipitation increases in regions where the hotspot has a negative sign such as the southeast of the domain” -> unclear. Larger increases where the change is negative?
l.179 “larger scale means” -> “global average”
Figure S5: What are OBS? It would be better to show here the values for the different observation/reanalysis products. Or at least their mean and the range across products (maybe that is what is currently shown, and if yes, please specify in the caption) In HighResMIP values the different markers are also a bit too small to see the difference. Make them bigger maybe?
l.206 “for the remaining seasons” -> “for MAM and SON” (or specify in the previous sentence that you look at DJF and JJA).
l.210 “trend” -> “trends”
l.211 “but the PR high-resolution (HR) models trends display outliers in summer” -> “but some of the high-resolution (HR) models exhibit trends outside the CMIP6 range for PR in summer”
Figures 3 and S6: Could you please add horizontal grid lines? Right now it is difficult to look at this figure and see the differences between weighted and unweighted results.
l.220 “under for” -> “under”
l.227 “cannot be drawn”. Still, you could compare the HighResMIP values with those of the corresponding, low-resolution climate model versions.
l.229 delete “respectively”
l.237 Figure S5, not S3
ll.237-238 “Generally, the signal is weak and the inter-model spread is wide for all multi-model ensembles” -> what does this refer to? Precipitation projections only? If yes “weak” is not really appropriate. Mid-to-long term trends in JJA precipitation are large (-15% or below)
ll.240-244 What is the conclusion here? If you constrain model ECS then you will get a smaller spread in projections.
l.248 “Student’s t-test”
l.253 “CMIP6 systematically projects” instead of “keeps projecting”
l.260 “precipitation changes only get more robust and significant with time” -> does this mean that temperature changes don’t get more robust and significant with time?
l.265-267 Please rephrase.
l.267 “concord” -> “agree”
l.272-273 It sounds like you are saying that precipitation both increases and declines in the Balkans.
l.276-277 This sentence comes a bit out of nowhere. Also, what is the 90% range? Please clarify.
l.278 suggest “Weighted projections” to be consistent with section 3.2
l.293 “The mean signal in CMIP6 decrease whereas it increases in CMIP5”
ll.297-298 “Nevertheless, even if the probability of a future extreme-warming decreases, such temperature increases are still considered valid by the weighted ensemble” -> I suggest rephrasing along the lines of “Nevertheless, even though the weighting approach reduces the probability of the most extreme warming values, they remain possible in the weighted ensemble”.
ll.306-307 suggest rephrasing as “We have shown that average Mediterranean temperature changes were larger than the global-mean average during summer, but close to it during winter, for all scenarios, time periods and model ensembles.”
l.324 “no clear improvement could be seen from the increased resolution” -> did you compare the HighResMIP models with the lower-resolution versions of the same GCMs?
l.330 “The largest source of uncertainty to determine the warming and precipitation change by the mid and long-term periods is the emission scenario.” Where did you show that? Is it true for both TAS and PR?
l.365 “Precipitation weighted projections are not shown in this study as we have no proof that the diagnostics used to assess temperature are relevant to evaluate the models’ precipitation response.” -> you could still weigh models based on their past precipitation trends, no?