I thank the reviewer for the constructive comments.  However, the editors of the journal requested a text of no more than 1300 words, a particularly tight limit. To respond correctly and fully to the reviewer's requests, and to fully elaborate on the reviewer's - albeit very interesting! - points and concepts, one will need well over 1300 words. Nevertheless, I will try to make use of the reviewer's comments.  

Response to the comments of the first reviewer

The manuscript “Invited perspectives: Landslide populations - can they be predicted?” provides a very interesting concise review about what approaches and data is available for predicting hazard and risk of populations of landslides. The manuscript is very well structured into the individual questions: where? when or how frequently? how many and how large? Consequences? 

From my point of view this is valuable, however, with adding some more information and particularly ideas for perspective and the way forward, this manuscript can become significantly more interesting for the scientific community. 

I am pleased that the reviewer has found the manuscript valuable, and I thank the reviewer for the positive comments and the useful recommendations.

Thus, I suggest the following: For each of the tackled questions knowledge gaps are presented. It would be great to put this somehow in order in respect to the urgency they should be closed. Please add some more information on which problems are important to solve (and maybe which are not so important but scientifically interesting). Please add one paragraph on what is the most pressing knowledge gap or challenge in respect to landslide predictions. Elaborate why it is important to solve this problem, if possible link this to practical problems of civil protection. 

As I have written in a previous post in response to the comment of this reviewer, the Editors have requested a (very!) short article, which will be part of a special issue celebrating the 20th anniversary of the journal. The limits in length, make it very difficult to respond fully to the request of the reviewer. As requested, I have added a new paragraph in the text.

The new language reads, “Of the various factors governing landslide hazard the most uncertain and the one requiring more urgent efforts is the time prediction (when, how frequently), followed by the prediction of the size and number of expected failures. For both, multi-temporal inventories and landslide catalogues are essential to build innovative predictive models. To construct the records, systematic efforts are needed for landslide detection and mapping (Mondini et al., 2021). For susceptibility (where), the challenge is to have reliable regional, continental, or global assessments (Stanley and Kirschbaum, 2017; Broeckx et al., 2018; Wilde et al., 2018; Mirus et al., 2020). Critical are also novel modelling frameworks combining the hazard factors (Lombardo et al., 2020). But the goal is to reduce risk (Glade et al., 2005). For that, vulnerability studies, improved early warning capabilities, quantification of the benefits of prevention, and better risk communication strategies are crucial (Guzzetti, 2018).” 

Since this is an invited perspective, I suggest to elaborate more about the next steps and the way forward, 1) in respect to what is needed from science, what scientific suggestions do you have, what approaches should be followed, which studies should be undertaken. At the end “convergence research” is mentioned, please elaborate more on how this could look like in respect to landslide prediction, what would be necessary to undertake convergence research of landslide prediction, etc. and 2) what are practical solutions, what can be done by practitioners in respect to landslide prediction, what are practical steps forward. 

Considering the mentioned restrictions imposed by the editors on the length of the article, I have done my best to address the issues raised by the reviewer adding language to the last paragraph of the article, which nor reads: “Ultimately, I note that in medicine – a field of science conceptually close to the field of landslide hazard assessment and risk mitigation (Guzzetti, 2015) – the paradigm of “convergence research” is emerging (Sharp and Hockfield, 2017), where “convergence comes as a result of the sharing of methods and ideas … It is the integration of insights and approaches from historically distinct scientific and technological disciplines” (Sharp et al., 2016). The community of landslide scientists should embrace the paradigm of “converge research”, exploiting the vast amount of data, measurements, and observations that are available and will be collected, expanding the making and use of predictions, assessing the economic and social costs of landslides, designing sustainable mitigation and adaptation strategies, and addressing the ethical issues posed by natural hazards (Bohle, 2019). This will contribute to advancing knowledge, and building a safer society (Guzzetti, 2018).”

It would be interesting to know what this all means for practice, e.g. the Italian Civil Protection. How severe is the landslide risk in Italy? What are the main challenges and problems Italian Civil Protection is facing in respect to landslides? How do they approach the landslide risk and what are they planning to do about it in the future? Please add at least one paragraph about these practical aspects. 

I have considered this comment thoroughly and, in the end, I have decided not to discuss the issues posed by the reviewers; for two main reasons. First, the paper is meant to be general, and not focused on Italy and on what the Italian Civil Protection does to address landslide risk in Italy. Second, an – even very synthetic – discussion of the topic will require quite a bit of text, which is not available given the format of the paper.

Response to the comments of the second reviewer

I read with interest this invited perspective that is concise, clear, and well-focused in its purpose. The article is aligned with the goals of the 20th anniversary of the journal Natural Hazards and Earth System Sciences (NHESS) Special Issue. The discussed topic is relevant. 

I am pleased that the reviewer has found the manuscript of interest and the topic relevant, and I thank the reviewer for the positive comments and the useful recommendations.

However, there are few minor points that could be improved, and therefore help the readers to better catch the message of the entire work. I summarize these in the following points:

I respond to the comments of the reviewer below.

“the point of view of the organization”, in this case, “Dipartimento della Protezione Civile” of Italy, should be further described, with just 2-3 more sentences (but we cannot enlarge too much the work giving the SI purpose of two-pages limit) on the operational point of view of landslide prediction & mitigation framework. The authors are curious to see and learn from the Italian case study.

I have considered this comment thoroughly and, I have decided not to discuss the point of view of the Italian “Dipartimento della Protezione Civile” of Italy” for two reasons. First, the paper is meant to be general, and not focused on Italy and on what the Italian Civil Protection does – or does not – to address landslide risk in Italy. Second, I am not really entitled to provide the official perspective of the “Dipartimento della Protezione Civile”.

Line 42: when discussing "remote sensing imagery" I suggest mentioning the name (within brackets) of the remote sensing technologies (which are commonly used in preparing landslide maps).

I have edited the text as requested. The new text reads “The increasing availability of remote-sensing imagery (optical, SAR, LiDAR), some of which is repeated over time and free of charge (Aschbacher, 2017), opens …”. 

Line 63-64: the authors indicated that the number of studies projecting the future occurrence of landslides is increasing; here few key citations are necessary (we can exceed with citations since they are not included in the two-pages limit).

I have added the requested references. The new text reads “The literature on the analysis of historical landslide records remains scarce (Rossi et al., 2010), but the number of studies projecting the future occurrence of landslides is increasing (Gariano et al. 2017; Peres and Cancelliere, 2018; Schlögl and Matulla, 2018; Patton et al. 2019; Schlögel et al. 2020; Gariano and Guzzetti, 2021)”. 

Line 77, and in general in the entire work: the landslide types are not discussed or classified; this could be an interesting point for NHESS readers, but I understand that giving the limit of 2 pages and the focus of the work, maybe it is difficult to address. However, I would suggest thinking if there is a possibility to speculate a little on this, simply mentioning some landslide type when citing the literature. 

As the referee has indicated, it would have been very difficult to address the many issues related to the prediction of the hazards posed by different landslide types in a very short article. However (a) I maintain that the content of the manuscript is general and applies to most landslide types; and (b) I now specify in the text that the manuscript deals with all landslide types.