**6. Survival**

142 Prostate Cancer – Diagnostic and Therapeutic Advances

This approach has been facilitated by recent anatomical descriptions of the periprostatic

Dissection of the neurovascular bundles can be done in an intrafascial plane (directly adjacent to the prostatic capsule; complete nerve sparing), an interfascial plane (within the lateral prostatic fascia; partial nerve sparing) and extrafascial plane (outside the lateral

Deep dissection beneath Denonvilliers' fascia posteriorly should be performed routinely, as few nerves are present in this area and deep dissection will reduce the incidence of

Large, high-grade cancers, near the base of the prostate, or in the anterior transition zone often invade the bladder neck. For anterior cancers, begin division of the bladder neck a centimeter or more from its junction with the prostate. For large posterior tumors or those with seminal vesicle invasion, include the posterior bladder distal to the interureteral ridge

For patients with low risk disease, PLND is not necessary and is not recommended, because

For patients with high and intermediate risk disease, extended PLND at least for external iliac, obturator and hypogastric lymph nodes should be performed during radical prostatectomy. Removing at least 10 lymph nodes is recommended to detect LNI. (52) Prostate cancer lymphatic spread ascends from the pelvis up to the retroperitoneum invariably through common iliac lymph nodes. PC lymphatic spread can be divided in two

So the technique try to remove all lymphatic tissue between the external iliac vein and hypogastric vein above and below the obturator nerve, including the hypogastric and

Therefore may assert that an eLND should be performed in all high-risk cases, as the

However, despite the above, some authors like Bubley are not so categorical in affirming this. Although it is generally accepted that eLND provides important information for prognosis (number of nodes involved, tumour volume within the lymph node, capsular perforation of the node) that cannot be matched by any other current procedure, consensus has not been reached as to when eLND is indicated and to what extent it should be performed. When making such decisions, many physicians rely on nomograms based on pre-operative

As stated earlier, currently, a multimodal treatment is chosen to increase survival and

The EORTC Trial 22911 included 1,005 patients with positive surgical margins or pT3 disease (extracapsular extension and seminal vesicle involvement) and randomized them to adjuvant EBRT (50 Gy to the prostatic fossa and periprostatic tissue plus a 10–14 Gy

reduce biochemical progression. In this sense the RT play an important role.

main levels: pelvic and common iliac plus retroperitoneal lymph nodes. (53)

estimated risk for positive lymph nodes will be in the range 15-40%. (10)

anatomy. (51)

prostatic fascia; nerve resection)

**5. Pelvic lymph node dissection**

biochemical markers and biopsies. (54)

**Indications for RT after RP**

**5.1 Role of RT in high risk prostate cancer**

There are two important studies about this:

the chance of metastasis is low.

obturator lymph nodes.

posterolateral margins.

in the specimen. (48)

Regarding cancer-specific survival rate, and the overall survival rate, there are many studies, with different results (table 4).

First, in terms of morbidity, Berglund and colleagues (58) showed, that recovery from surgery, duration of catheterization, and the overall return of continence were essentially similar to those observed in the low-risk population.

Another important factor to consider when analyzing survival, is the overstaging sometimes happens in the T3. Therefore, Ward et al report a long-term experience with radical surgery in patients presenting with locally advanced (cT3) prostate cancer, as the best management of such patients remains a problem. They found that, significantly many patients with cT3 prostate cancer were over-staged (pT2) in the PSA era, and RP as part of a multimodal treatment strategy for patients with cT3 disease offers cancer control and survival rates approaching those achieved for cT2 disease. (31)

For short term survival, Loeb et al (35) reported a complication rate of 11% in 288 consecutive high-risk patients treated by RP, which was not different from the rate in a previous study from the same group that included 3,477 consecutive patients with prostate cancer (59) when analyzing intermediate-term cancer control, and quality-of-life outcomes after radical retropubic prostatectomy (RRP), and concluded that RRP offers excellent intermediate-term cancer control for selected men, of all ages, who present with high-risk or locally advanced disease. Both, continence and potency, were preserved in most patients, although the potency rates were significantly greater for the younger men. RRP with appropiate postoperative radiotherapy and/or hormonal therapy is a reasonable treatment option for selected men with high-risk or locally advanced disease. (35) (Table 4)

Radical Prostatectomy in High Risk Prostate Cancer 145

**organ**

Gleason 8-10 274 35 53 88 PSA > 20 275 33 56 91 T3c(\*year 1992) 144 22 49 89

5 years ≤50% 391 28 53 92

ng/mL/year 952 63 80 97

Gleason 8-10 957 43 68 93

Gleason 8-10 1752 51 73 95

Local control, main objective with both techniques, is better achieved with surgery. Local relapse rates between 3-30%(63-65) Depends on clinical stage (pT2: 2-7%; negative margins 7%; pT3-4: 40%; positive margin 27%) While with Radiotherapy, local recurrence rate is for

The rate of positive biopsies is between 20-70%, although is difficult to classify its meaning, they highlight disease and progression. It depend on clinical stage (B=17%, C=59%) and

Frequency of positive prostate biopsies on patients whom underwent radiotherapy, is

In the study (66) with 100 patients, with biopsy every 6 months showed following results T-

There is no doubt regarding its prognostic value. Although the pioneers showing these results were Rhamy (1972) and Sewel (1975) Scardino has been reporting, and highlighting its value (67). At Baylor-Collegue (Houston) 147 patients treated with Au 198 and external bean radiotherapy, clinical stage A2, B, C with pelvic lymphadenectomy. They had a positive biopsy rate of 42%, 36%, 28% at 6, 12 and 18 months. The chance of local recurrence at 5 years for positive and negative biopsies is around 52% and 12%, and at 10 years of 72% and 30%.

Many cancers, categorized clinically as high risk, are actually pathologically confined to the prostate, and most men with such cancers who undergo RP, are free of additional therapy

For men with high-risk, clinically localized prostate cancer, decisions on whether to elect surgery as local definitive therapy should be based on the best available clinical evidence

rather than on an individual practitioner's experiences and biases.

Gleason score. A valuable biopsy is at 18 months after finishing treatment.

**% free survival in 5 years**

**% cancer specific survival in 10 years**

**Criterion R Nº patients % confined**

T1: 17-22% (Standford); 4.6% (Schelhamer); T2: 19%-35%.

Nomogram PFP

PSA velocity >2

PSA≥ 20 o ≥T2c o

PSA≥15 o T2Bc o

**7. Local control**

around 38% on average.

**8. Conclusions**

long after surgery.

1b: 21%; en T-2a: 24%; en T-2b-c: 28%.

Table 5.

BR: Bioquimical recurrence NR: No results.

Table 4.

For long term survival, Van Poppel (60) showed in 2006, that in patients with locally advanced disease, the cancer-specific survival rate after RP at 5- and 10-years of follow-up, was 85-100% and 57-91.6%, respectively. The overall survival rate at 5 and 10 yr was, 75% and 60%, respectively. In patients with high-grade prostate cancer (Gleason score> or =8), the biochemical recurrence-free survival, after RP at 5 and 10 yr of follow-up was, 51% and 39%, respectively.

Van Der Ouden et al. determined the progression and survival rates, and investigate subgroups of patients who may not benefit from this treatment. Defining that Radical prostatectomy as monotherapy, in patients with locally advanced non-metastatic prostate cancer (T3) produces acceptable results, in those with well or moderately differentiated tumors. The results of progression and survival, are not significantly different from those patients with organ confined prostate cancer. (29)

Yossepowitch describe the results of RP in their patient's serie, classify patients in risk groups: (61) he studied pathological and clinical outcomes among high-risk patients treated with RP. To identify high-risk subsets, eight definitions from the medical literature were applied. Depending on the criteria, high-risk patients comprised 3% to 38% of the entire study population, highlighting the immense variability among available high-risk definitions.

High-risk patients were more likely to exhibit adverse pathological features (35%–71% with extra capsular extension, 10%–33% with seminal vesicle invasion, and 7%–23% with lymph node involvement), but roughly one third (22%–63%) had organ-confined cancers and nearly half (41%–74%) remained progression-free 10 years after surgery alone. (Table 5)

More recently the group from the Mayo Clinic, has reported their long-term result after radical prostatectomy versus external bean radiotherapy for patients with high-risk prostate cancer. (62) The 10-year cancer specific survival rate was 92%, 92% and 88% after RRP, EBRT plus ADT and EBRT alone. After adjusting for case mix, no significant differences in the risks of systemic progression or prostate cancer death were observed between patients who received EBRT plus ADT and patients who underwent RRP. However, the risk of all causes of mortality was greater, and statistically significant, after EBRT plus ADT than after RRP.

Table 5.

144 Prostate Cancer – Diagnostic and Therapeutic Advances

**% 5 years BR free survival**

8-10 281 65 NR

or PSA ≥15 o T3 288 39-53 70-93

Gleason ≤7 32 3mo:90 NR

For long term survival, Van Poppel (60) showed in 2006, that in patients with locally advanced disease, the cancer-specific survival rate after RP at 5- and 10-years of follow-up, was 85-100% and 57-91.6%, respectively. The overall survival rate at 5 and 10 yr was, 75% and 60%, respectively. In patients with high-grade prostate cancer (Gleason score> or =8), the biochemical recurrence-free survival, after RP at 5 and 10 yr of follow-up was, 51% and

Van Der Ouden et al. determined the progression and survival rates, and investigate subgroups of patients who may not benefit from this treatment. Defining that Radical prostatectomy as monotherapy, in patients with locally advanced non-metastatic prostate cancer (T3) produces acceptable results, in those with well or moderately differentiated tumors. The results of progression and survival, are not significantly different from those

Yossepowitch describe the results of RP in their patient's serie, classify patients in risk groups: (61) he studied pathological and clinical outcomes among high-risk patients treated with RP. To identify high-risk subsets, eight definitions from the medical literature were applied. Depending on the criteria, high-risk patients comprised 3% to 38% of the entire study population, highlighting the immense variability among available high-risk definitions. High-risk patients were more likely to exhibit adverse pathological features (35%–71% with extra capsular extension, 10%–33% with seminal vesicle invasion, and 7%–23% with lymph node involvement), but roughly one third (22%–63%) had organ-confined cancers and nearly half (41%–74%) remained progression-free 10 years after surgery alone. (Table 5) More recently the group from the Mayo Clinic, has reported their long-term result after radical prostatectomy versus external bean radiotherapy for patients with high-risk prostate cancer. (62) The 10-year cancer specific survival rate was 92%, 92% and 88% after RRP, EBRT plus ADT and EBRT alone. After adjusting for case mix, no significant differences in the risks of systemic progression or prostate cancer death were observed between patients who received EBRT plus ADT and patients who underwent RRP. However, the risk of all causes of mortality was greater, and statistically significant, after EBRT plus ADT than after RRP.

**% 10 years cancer especif survival**

**Patients**

Ouden (29) T3 clínic 136 39 72 Hsu (26) T3 clínic 235 60 92 Ward (20) T3 clínic 841 58 90; 15 y 79 Lau (23) Gleason 8-10 407 49 85

**<sup>↑</sup>Risk Nº**

Van de

Van Poppel (27)

NR: No results.

39%, respectively.

Table 4.

BR: Bioquimical recurrence

Berglund (19) PSA ≥15 or Gleason

Loeb (21) T2 and Gleason 8-10

T3a y PSA ≤20 and

patients with organ confined prostate cancer. (29)


*Article* **Young People Are Changing Their Socio-Ecological Reality to Face Climate Change: Contrasting Transformative Youth Commitment with Division and Inertia of Governments**

**Alfredo Pena-Vega 1,\*, Marianne Cohen 2, Luis Manuel Flores 3, Hervé Le Treut 4, Marcelo Lagos 5, Juan Carlos Castilla 6, Aurora Gaxiola 6 and Pablo Marquet 6**

**Abstract:** This paper contributes to a critical re-reading of the notion of climate services. It does so by problematizing the discontinuity between young people's commitment to climate change, and the lack of a common vision regarding climate policy among governments. In this essay, youth commitment is characterized in terms of participation in the Global Youth Climate Pact (GYCP, 2015–2022). Here, young people share projects from their own high schools and communities and participate in a citizen consultation. Most projects have achieved a good success score, increasing over the years, especially for those carried out in emerging and developing countries. Some of them were presented at the COPs. In contrast, a textual analysis of intended nationally determined contributions (INDC) illustrates divergent understandings of the Paris Agreement and exemplifies the poor results of governmental climate diplomacy. This study establishes the need to closely monitor early warning signs of climate change in conjunction with high schools and school communities. The initiatives of young people are building a civic and planetary awareness for climate change in contrast with governmental division and inertia. In this sense, climate services, directed to young people, could contribute to design a sustainable future. We approach the practices, attitudes, and commitments of young people from the angle of cooperation rather than a moral vision of responsibility. Particularly, we propose a dialogical link between the treatment of climate issues and its effects on the constitution of networks, notably as they relate to practices of action, that is, the way in which distinct groups of young people develop relationships with their environments, organize themselves, and act and transform reality.

**Keywords:** young people; involvement; climate services; knowledge; awareness; transformation action

### **1. Introduction**

The environmental challenges that humanity is facing in the 21st century, and climate change in particular, require a radical transformation in the way we dwell in, inhabit, and understand nature. Responses given by the governments are still below requirements, despite the mobilization of part of the international community [1], including researchers, citizens, and particularly, young people. A complex and integrative vision of the world is needed to tackle climate change issues, including the cultural diversity between countries [2,3] and generations. There is an urgent need to change the way we prepare the next generation of scientists and social leaders to effectively deal with the problems of the Anthropocene [4]. Unfortunately, there is a shortfall in the way we effectively teach

**Citation:** Pena-Vega, A.; Cohen, M.; Flores, L.M.; Le Treut, H.; Lagos, M.; Castilla, J.C.; Gaxiola, A.; Marquet, P. Young People Are Changing Their Socio-Ecological Reality to Face Climate Change: Contrasting Transformative Youth Commitment with Division and Inertia of Governments. *Sustainability* **2022**, *14*, 15116. https://doi.org/10.3390/ su142215116

Academic Editors: Charles Herrick, Jason Vogel and Glen Anderson

Received: 31 July 2022 Accepted: 27 October 2022 Published: 15 November 2022

**Publisher's Note:** MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.

**Copyright:** © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

subjects such as climate change in the classroom due to a variety of causes, ranging from ideology, inadequate training, and state or country level ordinances, for example [5–7]. This is a cause for concern, considering the growing disconnect between young people and nature [8].

To what extent are climate services an appropriate method to undertake such issues? According to the analysis of the 27 volumes published by the Climate Services Journal (2016–2022, Appendix A), climate services seek to provide understandable climate data and scenarios to facilitate decision-making by individuals, governments, economic interests, and public sector actors. Climate services often entail the co-production of indicators that make sense to stakeholders, considering their perceptions and knowledge and evaluating the relevance of communication tools (web service, mapping, application). However, the climate services enterprise needs to be challenged to better support interdisciplinary, action-directed educational efforts. As an original contribution, this notion has not yet been applied for education purposes nor addressed to young people. Our approach is, therefore, innovative, seeking to increase awareness among a social category thus far underaddressed in the climate services literature and research. In this sense, our project adopts an action-based research approach to inform future leaders who will have to cope with climate change. Co-construction is at the heart of the pedagogical approach we advocate.

In the first section, this paper reports the case study of the Global Youth Climate Pact (GYCP hereafter) project and the methodology used to monitor and assess its efficiency and effectiveness, compared to the inertia and division of governments. The second section traces how GYCP was driven by young people's growing concern about climate change, the transformation that the GYCP project generates in students, in their awareness of the problem and in their eagerness to become actors of change. The third section compares this transformative pathway with the fragmentation of views and inaction of the governments, highlighted by a mapping of the discourse underlying the contribution made by governments to the Paris agreement. The conclusion puts this experiment in perspective with those conducted in the context of climate services.

### **2. Presentation of the Study Case and the Methodology**

### *2.1. The GYCP Project: An Urgent Need for an Active and Participative Pedagogy*

The GYCP project began in 2014 as a response to the critical lack of involvement from young generations and insufficient consideration of the human dimensions of climate change in the COP meetings and reports. Developed in 30 countries (Figure 1), it involves more than 12,000 young people and prioritizes their awareness and continuing education. The question was whether young people were aware of the challenges and opportunities that a pathway toward a low-carbon model entails and ready to join the world debate on the ways to reach it. In this context, we contacted schools and science teachers in different countries to carry out a pilot experience of reflecting on climate change in the school and in their localities. This reflection process led to the organization of projects by the students and required further knowledge to support the work of both teachers and students. Scientists have a leading role to play in this process. As agents of knowledge dissemination, they interacted with students to explore scientific results, issues and uncertainties about global warming, and helped build their pilot projects.

Our approach differs from traditional pedagogy, which tends to treat young people as mere receptacles of adult knowledge. In this context, it is critical that climate change is understood by young people and not merely explained to them. This new paradigm needs to tackle creative complexity, particularly in the field of education [9–11]. It points to the need for a new teaching strategy that embraces the interconnected nature of planetary society, where fundamental notions such as uncertainty, interdependency, and nonlinearity become embodied knowledge, thus, aligning the increasing commitment of young people with their ownership of scientific knowledge. This issue is opening a new field of research [10,12–15] and action–research projects such as the Global Youth Climate Pact (http://www.globalyouthclimatepact.eu/ (accessed on 30 July 2022).

**Figure 1.** Map of the discourse underlying the intended nationally determined contributions (INDC) to the Paris Agreement and locations of the GYCP projects. Realization: Marianne Cohen (Material English, French and Spanish corpus: INDC https://unfccc.int, accessed on 30 July 2020, location of GYCP projects: http://www.globalyouthclimatepact.eu, accessed on 30 July 2022; Method: lexical analysis by context of the 3 corpus with IraMuTeQ free software; Mapping: ArcgisPro© software.

### *2.2. Young People, at the Crossroads of Knowledges and Cultural Diversity*

Contrary to current stereotypes of young people [16,17], the GYCP experience demonstrates that they are not disengaged from the ongoing climatic crisis. They are eager to understand and find ways to generate actions in the face of governmental inaction. They desire to be agents of change now and in the future. Drawing upon this awareness, one can conclude that there is a great opportunity to propose action-oriented pedagogical experiences that nurture this interest and transform it into ways of knowing and creating citizens that can fit into a carbon neutral world by 2050. This requires, however, rethinking the dominant discipline-oriented teaching paradigm and working instead toward problemoriented strategies that allow and enable contributions from all disciplines, integrating and crossing knowledges and enhancing the open-mindedness of all the actors of the teaching system [18,19]. In particular, it is critical to develop an open-minded learning by doing and to create learning institutions that serve human interactions. In this sense, the GYCP experience points toward the opportunity and need for a radical re-reading of the notion of climate services (Appendix A).

### *2.3. Methodology Used to Monitor and Assess the GYCP Project*

Several methods were used to monitor the projects and assess the growing awareness of the students and to co-construct a common parlance and vision while respecting cultural diversity. During the large meetings that brought together the delegations of all the countries, we used crowdsourcing to question a large panel of participants dynamically, including those who were physically present. This method, implemented with the help of an external service provider specializing in this technique, made it possible to obtain significant statistical results. The main question asked referred to the degree of sensitivity of young people to the impact of climate change. Three editions followed one another, in 2015 during the COP 21 with 600 participants, in 2017 with 918 participants, and in 2019 during the COP24 in Madrid with 300 participants.

During the development of the project in each country, we used focus groups to capture and characterize the experience of specific groups of students. The focus groups made it possible to bring to light deep-seated questions on the part of the young people and stimulate the appropriation of the knowledge related to climate change, its integration in their cultural reality, and the elaboration of action-oriented projects.

We also sought to evaluate the success of 53 projects by developing a composite index, taking into account the focus of the projects, their ability to be disseminated in the wider youth community, and the level of concrete realization they achieved. Each of these criteria were scored from 1 to 4 (Table 1), providing a readable indicator for evaluating the projects and comparing their level of success.

**Table 1.** Multi-criteria assessment of the success of projects.

Finally, we compared the accomplishment of the young people who participate in the GYCP project with governmental inertia and fragmentation of national policies. With this aim, we overlaid the location of all the GYCP projects with a map highlighting the diverse ways governments understood their engagement to the Paris Agreement. This map was produced by analyzing the intended contributions of 191 countries with an automatic method (Appendix B).

### **3. The GYCP Project, a Process from Consciousness to Action**

*3.1. A Growing Youth Concern and Engagement*

According to our first (2015) crowdsourcing survey during the COP21 with 600 young people, more than 89% of respondents said that they and their families were concerned about climate change. While it is not surprising that individuals attending a COP would be highly focused on climate change issues, this is nevertheless a high proportion, especially when considered in light of pervasive, widespread stereotypes of a youth that is uninformed and uninterested in climate issues [16,17]. We differentiated the answers according to the origin of the young people: developed countries (European origin), emerging countries (China, India, Brazil, Colombia, Chile), and developing countries (Guinea, Burkina-Faso, Lebanon, Nepal). Thus, while 87% of young people from developed countries said they were concerned, 100% of young people from emerging countries and 94% of those from developing countries did so. The level of concern is higher in emerging and developing countries and lower among young people from developed countries, perhaps because they perceive climate change as a distant threat, removed from their lives both in space and time. It could be argued that at that time (2015), in the minds of people and including young

people, climate change risks were perceived as non-personal, about the future, other places, and other species (plants and animals, not humans) [1].

Comparing these results with the 2017 survey on perceived impacts, we also see a shift. Indeed, among the 918 exchanges of views that generated the most interest, 41.5% believe that extremely negative impacts will be felt in terms of rising sea levels, land flooding, and the disappearance of some cities (Venice) or island countries (Kiribati, Maldives). In 2017, the proportion of the risk of natural disasters was twice as low (21%), on par with concern about a disruption of the seasonal cycle.

During the COP25 held in Madrid in 2019, this concern was shared by 15.4% about one or more of these disasters. In the same year, the second most important concern (24%) was about the lack of water resources, desertification, and the increased risk of famine, a result similar to 2017. A smaller proportion of exchanges (18.9%) revealed concern about the reduction in biodiversity, more than twice as many as in 2017. When asked about the impact of climate change on their way of life, 300 young people from 8 European and Latin American countries gave a clear answer: more than 90% of the responses from young people from Europe and Latin America agreed that global warming would have negative or very negative consequences. There is a convergence of views compared to the 2015 survey, the negative or very negative impacts of global warming are, all things considered, identical in terms of percentages. In 2019, unlike in 2015, young Europeans were proportionally more likely than young Latin Americans to perceive negative impacts; they were no longer seen as a distant threat by 96.5% of them [20].

We take these figures as an illustration that shows that students from emerging countries were more likely to experience, in their own lives, the impact of climate change in the year 2015, whereas the concern about climate change is nowadays shared by all students whatever country they are living in.

### *3.2. Young People May Be the Wellspring of Socio-Ecological Change*

Concrete examples are given by the diagnosis established by learners in contrasting geographical contexts (Figure 1). Projects carried out under the GYCP came from young people living all over the world: central France, Colombia, Brazilian Amazonia, rain forest in central Africa, semi-arid northern Chile, Easter Island, and northern Argentina, and all highlight a multi-level ecological deficit. From their diagnosis, they set up specific action projects and contribute to socio-ecological change in their territories. During this process, scientists provide their knowledge, and learners contextualize it to elaborate a diagnosis and further an action plan, teachers being the linchpin.

A key point, brought in by the students' projects, is how ancestral knowledge may contribute to thinking about the future under climate change, particularly in territories where the memory of the past has a great importance in knowledge transmission. For example, in the Puyanawa indigenous community of Brazilian Amazonia (Appendix C), a link was established between the students and the elders' knowledge, and the diagnosis and action project were translated into the indigenous experience. Other projects by young Pygmies belonging to Bantu, Nilotic, and Sudanese communities, living in the Congo Basin Forest, were engaged in combating deforestation as "forest gatekeepers". In Easter Island, students were engaged in the reactivation and reinterpretation of the Rapa Nui techniques of "rock gardens" as a way of enhancing the sustainability of agriculture and addressing water shortages affecting the territory (Appendix C). From this insular experience, learners suggest rethinking "our planet like an island in the middle of the Universe". Other proposals are oriented on innovative technologies without abandoning the native heritage. In the Chincolco agricultural school in central Chile, learners are elaborating on a multi-objective hydroponic technology to adapt to water shortages (Appendix C), while students in the Azapa Valley of Northern Chile are reflecting on improving carbon sequestration in their local vegetation and wetlands. Young Colombians, on the other hand, are developing an agroecology book to bring alternatives to rural populations facing climate change, thus, becoming actors in one of the most important mitigation and adaptation strategies for

climate change, known as nature-based solutions [18,21,22]. In a French rural territory and in northern Argentina, scholars are rethinking the carbon footprint of their school canteen or their city and bringing a proposal at the regional level.

This demonstrates how each contextualized experience may facilitate or compel socioecological change when it is built upon a place-based reality anchored in experience, including the most recent projects designed during the health context of the pandemic. All these examples are creating virtuous circles in which young people are at the source of socio-ecological change, bridging the gap between traditional knowledge, local experiences, innovative solutions, and transformative change.

In the process of building projects with young people, we did not try to transpose the UN concepts. They were free to choose their own words, and what was important was creativity. The frequency of key words in the titles of the projects shows the way in which young people appropriate their "climate reality". Thus, among the titles of the 54 projects, 10 mention environmental issues, 9 citizenship and awareness, and the same number education or resources. According to a focus group, these notions underlie the notion of "transformation" that is dear to the hearts of the young people. The projects related to the climate issue as such occupy only the fifth position with eight efforts directly focusing on climate change. The notion of adaptation is not mentioned, and mitigation is rarely put forward (six projects), and this is the case regardless of the level of development of the countries where the young people live. Project success indicators show that most projects achieved a good score, increasing over time (average score from 4.4 in 2015 to 9.8 in 2021, decreasing to 7.2 in 2021 due to the COVID-19 pandemic). The level of success of the projects was inversely proportional to the level of development of the countries, the average score being 4.9 in developed countries, 6.6 in emerging countries, and 8 in developing countries. This shows that young people in countries where the effects of climate change are most dramatic are the most involved in finding local solutions (see Table 2).

**Table 2.** Results of the Multi-criteria assessment of projects.

### **Table 2.** *Cont.*

**Table 2.** *Cont.*

### *3.3. Youth Acting for the Adaptation to Climate Change*

These experiences are all based on the desire " to act now", but what is really acting? Contrary to the statement of Claudia Gorr [23], young people who participate in the GYCP do not agree that "citizens cannot do anything to mitigate climate change". This common vision also emerges from the claim for political action raised by the growing youth mobilization against climate change. In the GYCP, participant's drive to take action rests on their engagement and on a collective and reflexive participation primarily oriented towards adaptation to climate change and, secondarily, towards its mitigation. For half of them, "I, us, young people" can act against climate change; it is up to them. A considerable proportion think that it requires the involvement of all the inhabitants of the planet, with only a few thinking that governments have to play the major role. Contrary to other studies, the experience associated with the projects developed by students raised awareness of the importance of becoming involved in the struggle against one of the most important problems facing society, climate change. The experience of the GYCP provides information that appears to counter the conventional wisdom that young people do not take seriously the issues related to climate change. Nevertheless, there are clearly barriers to overcome in order to change the way we explain complex and multifactorial problems, such as climate change. This requires finding new forms of explanation. This problem could be addressed by enhancing a deep understanding by teaching through actions and by bringing scientists to schools to monitor the progress of projects and provide scientific evidence, which has the important co-benefit of fostering an appreciation for science and science-based actions.

### **4. GYCP Is at Odds with the Division and Inertia of the Governments**

The actions of youth seem at odds with the *climate paradox*: the more acute the consequences of climate change, the more divided and paralyzed are decision-makers [1,24,25]. Due to their engagement in local actions, such as those illustrated through the GYCP, young people provide hope and scope for action. Their projects were presented at the different COPs. In Paris, during the COP21 in 2015, we presented 21 proposals from 10 countries in a side-event to the organizers. The same happened at COP 22 in Marrakech in 2016 and at COP 23 in Bonn. In Katowice at COP 24, in 2018, posters reporting on the different projects (Appendix C) received a warm welcome from the assembled authorities, including ministers of the environment, the UN youth representative, the European Commission environment representative, and mayors of large cities. In Madrid, we were invited by the president of the COP to present our proposal for the future (six items: education) [26–28], valuing forests, reduced carbon footprint, biodiversity, resources, water and soil, sustainable agriculture, protection of the oceans, and nature in the city (see Appendix D), but this ended with a report being presented to her presidency coordinator. Should we see in this kind but short-lived reception an illustration of the distance between the concrete commitment of young people and the inaction of political leaders and a justification for

young people's lack of trust in decision-making processes at national and international levels? In Glasgow, the young people were not admitted to the conference for health reasons, but they did participate in a citizen's consultation, of which we made ourselves the spokespersons (Appendix E). From a report on the degradation of ecosystems, the growing role of social networks and a global crisis, they proposed among the solutions, acceleration of decision-maker actions, awareness among young people, and change in the dominant modes of consumption [29].

On the other hand, government discourse underlying their contributions to the Paris Agreement INDCs are revealing a divided world and explain the inaction on the part of governments (Figure 1). This division is shaped by strategic alliances (e.g., UNFCCC negotiation groups, OECD, ASEAN, Francophonie, Commonwealth ... ) beyond the "South-North" divide. As previously described, these discourses were evaluated by means of an automatic text analysis of the INDCs of 191 countries, first applied to the English corpus [30] and further to French, Spanish and English corpus separately, synthetized and mapped (Appendix B). Regions highly vulnerable to climate change have a fragmented view on the issue (Africa, island countries) that weakens their political force in the negotiations [31]. Developed countries focusing their INDC on the "Reduction of GHG emissions" constitute a more homogenous group strengthened by the efficiency of their negotiation groups. Emergent countries have different visions, either adopting the dominant discourse on the "Reduction of GHG emissions" (Chile, Brazil) or a composite discourse in line with the vulnerability of part of their territory (Mexico, South Africa). Inequalities are not enough counterbalanced by the financial aid brought to low-emitting countries to cope with climate change while a low proportion of countries focusing their INDC on the "Reduction of GHG emissions" and on the "Energetic transition" implemented a carbon policy, illustrating a disconnect between rhetoric and decision-making [20]. This may explain the disappointing results obtained five years after the Paris Agreement since CO2 emissions have continued to rise between 2015 and 2019 by 4.88%, in 8 out of 10 countries emitting nearly 70% of total carbon dioxide. The 2020 numbers show a reverse trend, related to the effects of the COVID-19 pandemic (www.carbonproject.com, accessed on 30 March 2022). While countries adopting the discourse on the reduction in GHG emissions moderately decreased their CO2 emissions (−1.8%), those focusing their INDC on energetic transition experienced a very strong increase (7.3%) (https://edgar.jrc.ec.europa.eu/overview.php?v=booklet2020 (accessed on 30 March 2022)) due to their high coal consumption, the exact opposite of the rhetoric behind their INDC. Beyond this geographical fragmentation, this inaction can also be interpreted by the low political benefit expected from the drastic measures needed, which will only materialize after 2050, given the inertia of greenhouse gases in the atmosphere. The distance between the INDCs and the actions, 7 years after the Paris Agreement, suggests a climate diplomacy made of magic words, very far from or even the exact opposite of the reality of political decisions. In this sense, the map of the discourse underlying the INDCs of the governments in 2015 was premonitory of the weak results obtained through COP26, which was, however, decisive. Far from the acceleration desired by young people, a policy of small steps has prevailed, leaving fears that the objectives of the Paris Agreement are out of reach.

### **5. Conclusion: Youth Lessons beyond the Cop26 and Renewing Climate Services**

As we are writing, the growing youth claim to act against climate change is another expression of their awareness and need for action. Involvement of the younger generation should go beyond wishful thinking or goodwill, and advance toward mobilization, such as the movement launched by Greta Thunberg. Young people of the GYCP involved in action-oriented projects conceived to change their territory are currently acting beyond the fragmentation between countries while nevertheless building their projects in recognition of cultural specificities. This demonstrates the importance of climate change education through active teaching methods but also the need to integrate them as qualitative indicators of countries' commitments, as proposed by the GYCP during the COP25. Young people

are opening new avenues that can bring a change to us all. Unfortunately, in Glasgow, decision-makers once again demonstrated their lock-in to short-sighted geopolitical divisions, contrasting with the promising narratives employed in their intentional contributions to the Paris Agreement. Our hope is thin that the voices of the young people were heard by their representatives, but despite this, the GYCP will continue its transformative action. Young people´s call for actions to mitigate and adapt to climate change and ultimately to foster multilateral cooperation is becoming stronger. It can provide the required additionality to cross the tipping point and help to address collective action problems associated with climate change, fostering an increase in countries´ level of ambition in their CO2 abatement commitments.

In this sense, the GYCP has great potential as a test bed for activities that could contribute to a renewal within the enterprise of climate services by deepening their objectives and applying them to a promising segment of society. Our approach, while inspired by certain aspects of the concept of climate services, is a rather radical re-reading of it on several points. Our partners are underprivileged high school students from the public sector. The researchers and associated teachers are volunteers. The depth of the co-construction of knowledge is far from both traditional pedagogy and the co-construction carried out within the framework of climate services, which aims at transforming knowledge and climate data into "useful" indicators for policy and economic activity.

From a social experimentation point of view, we solicit the collective intelligence of young people by suggesting a reflexive involvement and a conscious commitment from the elaboration of action and experimentation projects. The impact on educational orientations is reflected above all in the way we deal with the complexity of an essentially transversal subject. Our approach is the opposite of a utilitarian, top-down orientation. It is the group of students who, after a local diagnosis, suggest a contextualized and problematized project, according to a bottom-up approach. The question is not what researchers can solve in climate-vulnerable regions but what the "good actions" are that these young people can propose to obtain useful results. This suggests the benefits that may accrue through integration of place-based, ancestral knowledge in climate services. All these principles are the basis of a pedagogical book for teachers [18].

Appropriately configured, climate services may be a tool that can help young generations to cope with the dangers and perspectives linked with the increasing variability and change in climate; perhaps serving as a mechanism to reinforce actions undertaken by the students, similar to forest gatekeepers, stone-gardens, or agroecology. The question raised by this experience is how far climate services can support young people in their efforts to design a sustainable climate reality.

Finally, considering our results, we would like to highlight a line of thought, part of which is borrowed from Michael H. Glantz's book: Climate Affairs [32]). We have described how our project is based on three fundamental principles: reflexive knowledge, awareness raising, and the importance of socio-anthropology in the climate system. Although there are sophisticated models of global warming scenarios with increasingly advanced technological means to scrutinize our Earth, there are still a significant number of people who ignore the evidence of climate change. However, there are several ways of integrating a socioanthropological dimension to climate problematization. Some are tactical, others are strategic. On the tactical level, the socio-anthropological dimension can be considered in climate discussions when it directly, visibly, and largely, influences issues of societal change. On the other hand, a strategic focus on climate disruption leads to an overemphasis on the long-term climate change issue at the expense of the shorter-term socio-anthropological dimension. However, a multidimensional approach that encompasses both tactical and strategic concerns in time and space integrates the socio-anthropological condition into the overall complex problem of global warming. "We are in a world faced with the difficulties of global thinking, which are the same as the difficulties of complex thinking" [32,33].

**Author Contributions:** Conceptualization, A.P.-V., L.M.F., P.M. and M.L.; methodology: A.P.-V., L.M.F., M.C. and A.G.; software: M.C.; validation, A.P.-V., P.M. and J.C.C.; formal analysis, A.P.-V., M.C., L.M.F. and P.M.; investigation, A.P-V., L.M.F., P.M., A.G., M.L., J.C.C. and H.L.T.; resources, A.P.-V.; data curation, P.M.; writing—original draft preparation, A.P.-V., M.C., L.M.F. and P.M.; writing—review and editing, A.P-V. and M.C.; supervision, A.P-V.; project administration, A.P.-V. and L.M.F.; funding acquisition, A.P.-V. and L.M.F. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by French Ministry of Ecology, Region nouvelle Aquitaine. Chilean Ministry of Education, the Explore Program of Conicyt and the Centro de Cambio Global and Catedra Arauco en Etica Ambiental, F. Ciencias Biologicas, U. Catolica de Chile. We also received support from the Centro de Modelamiento Matemático (CMM), ACE210010 and FB210005, BASAL funds for centers of excellence from ANID-Chile and Grant ACE210006, AG and PM acknowledge support from Grant BASAL FB210006 to the Instituto de Ecología y Biodiversidad (IEB), AG acknowledges support from Projecto Anillo ACT192027.

**Institutional Review Board Statement:** Ethical review and approval were waived for this study because crowdsourcing has been done anonymously via a web platform.

**Informed Consent Statement:** Individual informed consent statement was unnecessary due to the use of the crowdsourcing methodology. Hundreds of students contribute simultaneously and anonymously to the discussions via the web platform Synthetron (http://synthetron.com accessed on 10 August 2022), identified only by their country.

**Data Availability Statement:** Data are not available due to our agreements with our external service provider.

**Acknowledgments:** We acknowledge students and teachers who participated in the GYCP project, the company who realized the crowdsourcing, Master students from Sorbonne Université who contributed to the INDC analysis (supervised by MC), students of Sciences-Po (Poitiers) who analyzed the information collected in Rapa-Nui (Supervised by APV) and Guillermo Marini, associated professor at the Universidad Católica de Chile, contributed to the revision of the English language.

**Conflicts of Interest:** The authors declare no conflict of interest.

### **Appendix A. Meta-Analysis of the Literature on Climate Services**

In order to define climate services, we listed and analyzed the titles of 212 articles published in the journal Climate Services, published by Elsevier, between 2016 and 2022 (https://www.sciencedirect.com/journal/climate-services (accessed on 10 August 2022)). Additionally, we used Google Scholar to search for articles associating the key-word climate services with "youth", "education", or "high school".

We found that 68% of the 212 titles focused on a region, a country, or a level of development; 36% were applied to developed countries; and 32% to developing countries. The remaining 31% had a global or a general approach. Less than half (43%) of the titles focused on the benefits of climate services on the economy, with agriculture being the main sector (25%). Another significant proportion (21%) referred to the contribution of climate services to risk management (floods, droughts, heat waves, etc.) without focusing economic stakeholders. Only one title out of 5 referred to the need for co-construction of indicators and to the perception and knowledge of stakeholders. A higher proportion (36%) referred to the description of climate data, projects or climate services in general, i.e., following the point of view of the researchers. No article associated the term climate service with youth, education, or high school in this corpus, neither on Google Scholar.

The lexical analysis, by context with IRaMuTeQ 0.7 free software, differentiated six types of titles of equal importance. More information on this software is given in Appendix B. The words and illustrative variables best related to the types are listed in the Table A1, along with the chi2 value that assess the strength of their relationship with the type. Only one type referred to a disadvantaged social category, namely, rural smallholders, preferentially published in volume 20 (year 2020). The others referred to market and methodological issues of data analysis and simulations that differ in time. The word citizen was used in only one title, and the words youth, student, or education were not used.

Six types of titles of Climate Services were published during the period 2016–2022, analysis with IRaMuTeQ 0.7 software

**Table A1.** Results of the lexical analysis by context of the titles of *Climate Services* journal.

### **Appendix B. Automatic Text Analysis of the INDCs of 191 Countries**

In order to explore the human dimension of climate change at the global scale, we applied a lexical analysis by context to 191 intended nationally determined contributions (INDCs) to the Paris Agreement (COP21). Furthermore, [34] assessed the expected effects of state commitments on greenhouse gas emissions.

We first downloaded the INDCs and gathered them in three corpuses, according to their language: English (558,641 words); French (66,026 words), and Spanish (45,065 words). We then formatted these three corpuses, deleted tables of numbers and graphs, corrected the spelling, and homogenized technical notations (for example CO2 eq).

We further processed each corpus using an R interface for lexical analysis by context with IRaMuTeQ 0.7 free software. Among many techniques, this type of lexical analysis is easily reproducible and well adapted to highlight the differences of views in a large corpus [35]. First used for literary analysis [36], it was applied to political or sociological purposes (i.e., [37]).

The software cut the corpus into basic context units containing about 200 characters, further grouped in context units, and then in significant statement classes using a descending hierarchical analysis. Each cluster was characterized by its own vocabulary according to the Chi-square test. Combined with a careful reading of the text, this analysis made it possible to understand the linguistic particularities of the different discourses. We detected six main types of discourses and then mapped out the significantly-linked discourse by countries, according to the Chi-squared test, by using the geographical information system (ArcGIS 10.2©).

**Appendix C. Three Examples of Projects presented in the COP24 in Katowice in 2018)**

**Figure A1.** Puyanawa: Traditional knowledges and Challenge changes. Source: Constant Josimo (UFRJ), GYPC.

**Figure A2.** Stone gardens: from the ancestors of Rapa-Nui to the world. Source: Young people, High school Aldea, Rapa Nui, GYPC.

**Figure A3.** Hydroponics for all. Source: Young people, High school Cordillera, GYCP.

### **Appendix D. The Proposals of Action in the Face of the Climate Emergency presented in COP25 in Madrid in 2019)**

**Table A2.** Working group, GYCP.

### **Appendix E. Listen to the Youth! Presented in the COP26, in Glasgow (2021)**

**Figure A4.** Listen to the Youth. Source: Survey post-COVID-19, 380 people.

### **References**

**Anna Boqué Ciurana 1,\*, Melisa Ménendez 2, María Suárez Bilbao 2 and Enric Aguilar 1**

**Abstract:** Surfing is one of the most popular activities in coastal tourism resorts. However, the sport depends strongly on the met-ocean weather conditions, particularly on the surface wind-generated waves that reach the coast. This study provides examples of how users' needs and user perspectives are considered by climate data specialists to develop needed, highly useful information addressing human and social needs. In this vein, the climate analysis of such data can provide input on the expected length of a surfing season, according to the surfer's level of expertise. In addition, other water sports, such as SUP Wave and windsurfing, among others, might be indicated when surfing conditions are not optimal. Finally, the safety of surfers and other tourists who venture into the sea is also dependent on those conditions. We collaborated with the surfing community to define a series of indices for quantifying surfing days (SD), surfing days stratified by surfers' skills (SDS), alternate offers (AOs), and surfers' and swimmers' safety (SuS and SwS). These are of general applications but require wind and wave data at a very fine scale as the input. To illustrate the potential of our indices, we applied them to the Somo beach (Cantabria, Spain). We downscaled a global wave hindcast dataset covering a 30-year period to a spatial resolution of 100 m to obtain wave-surfing information at Somo's surf spot. The results confirmed Somo's status as a year-round surf spot, with SD values of 229.5 days/year and monthly values between 22 days/month and 16 days/month. SDS showed different seasonal peaks according to the surfers' skills. Beginners' conditions occurred more often in the summer (18.1 days/month in July), intermediate surfers' conditions appeared in the transitional seasons (14.1 days/month in April), and advanced and big-wave riders in the winter (15.1 days/month in January and 0.7 days/month, respectively). The AO index identified the SUP wave values of 216 days/year. Wind water sports presented values of 141.6 days/year; conversely, SUP sports were possible on only 7.4 days/year. SuS and SwS identified different seasonal hazard values, decreasing from the winter, autumn, and spring to minimum values in the summer.

**Keywords:** resilience; wave climate; tourism management; surfing; climatology; decision making; climate service; sustainability; adaptation

### **1. Introduction**

Climate services are defined as the provision of climate information to help individuals and organizations make climate-resilient decisions. The World Climate Conference-3 (WCC-3), organized in 2009 by the World Meteorological Organization, established the Global Framework for Climate Services (GFCS) [1]. Climate data and information are transformed into customized products to provide decision makers in climate-sensitive sectors with better information to adapt to climate variability and change [2]. The goal of climate services is to provide access to scientific knowledge and, thereby, to reduce vulnerability and create opportunities to promote innovation, business opportunities, and employment, highlighting the importance of involving users in developing climate

**Citation:** Boqué Ciurana, A.; Ménendez, M.; Suárez Bilbao, M.; Aguilar, E. Exploring the Climatic Potential of Somo's Surf Spot for Tourist Destination Management. *Sustainability* **2022**, *14*, 8496. https:// doi.org/10.3390/su14148496

Academic Editors: Charles Herrick, Jason Vogel and Glen Anderson

Received: 18 May 2022 Accepted: 8 July 2022 Published: 11 July 2022

**Publisher's Note:** MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.

**Copyright:** © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

services [3]. Research has revealed [4] that peer-reviewed literature on the availability and use of climate services in the operations and management of tourism is scarce, and that a need exists for a new generation of specialized climate information products that can enhance climate risk management amongst tourism suppliers. Adaptation to climate change is becoming more urgent, but the wealth of knowledge that informs adaptation planning and decision making is currently not being used to its full potential [5]. In this context, climate services can provide valuable information that can help society enhance resilience, survival, and even prosperity in the face of climate risk [6].

Climate assessment for recreation and tourism have increasingly become dynamic research topics, especially in the age of the anthropogenic climate crisis [7]. Coastal destinations can offer different tourist activities in the same territory and all of them are influenced by meteo-climatic conditions to a specific degree [8]. We assert that there is a need to explore the climatic viability of different activities. By doing so, the development of climate services with tailored climate information about particular destinations can shed light on system changes.

The results of this research, specifically all the information generated with the indicators, imply an improved capacity for destination managers to promote particular destinations. This can lead to a destination being promoted in a more resilient way, not only by knowing which season is better for a specific level of surfing but also by knowing the viability of offering complementary activities. Thus, destination managers can plan tourist offers better and can be prepared to adapt activities when surfing is not possible. This will lead to investing in resources, from hiring staff to planning surfing championships, that will be planned more efficiently and sustainably. Definitively, using this information will enable destination managers to apply informed climate-resilient actions in their sector.

The present research bridges the gap between users and producers of climate information in line with our previous study, in which surfers and surf companies identified which meteorological and climatological information they need access to for better surfing experiences [9]. The new contacts that were gained through the survey conducted in the previous study helped the researchers of this study refine its focus.

Climate index application and validation for tourism is a complicated topic and presents several challenges [10–12]. In this context, the significance of this study is the need to transform meteo-oceanic data into information that can assist decision making in coastal destinations that need sustainable development. As coastal tourist destinations can offer different activities, we focus on surfing, one of the water activities that is offered at several destinations. Following the scientific literature, we have identified a gap in this specific activity and a need to develop a climate service that addresses it. Therefore, this research aims to contribute to the development of a specific climate service for surfing by considering specific users' needs and also by developing high-resolution meteo-oceanic data. The paper's primary objective is to present a set of climate indices for surfing destinations, taking as its experimental area the well-known Spanish surf spot of Somo (see the next section for details). With our analyses, we achieve two secondary objectives: (1) to obtain a downscaled dataset of wave data and (2) to describe with climate data the surfing potential of Somo's surf spot. As our results will specifically define the surfing potential of the spot, this information will assist surfing destination managers in promoting climate-resilient pathways for sustainable development in surfing tourism. In this regard, we intend to contribute modestly to the achievement of the various UN 2030 Agenda Sustainable Development Goals (SDGs), namely (3) good health and well-being, (8) decent work and economic growth, (12) responsible consumption and production, (13) climate action, (14) life below water, and (15) life on land.

### **2. Literature Review**

Several authors have defended the idea [13] that climate change communication and user engagement can work as a tool to anticipate climate change. The visual communication of climate information is one of the cornerstones of climate services; thereby, the characteristics that make a climate service self-explanatory rely on the type of representation used. In this context, guidance on the climate information published by official bodies should adopt a consistent approach, with a clear narrative that describes the transition from science to guidance [14]. The form in which climate services information is needed for the required end-user decisions requires careful thought, including appropriate communication of the associated uncertainties using best practices and experiences from related sectors [15].

Numerous authors have discussed the importance of climate [16], weather [17–21], and extreme weather [22–24] in the establishment and choice of tourism destinations. Outdoor recreation is strongly and increasingly affected by climate change and its impacts present marked seasonal and geographical variations that determine its viability [25]. In the past, the Tourism Climate Index (TCI) [26,27] has been used in suitability analyses. Several studies calculated this index to determine the climatic comfort conditions for tourism in different areas [28,29]. Specific research has focused on exploring the state of weather and climate information for tourism and explored sustainable tourism and the grand challenge of climate change [30,31]. Regarding the idea of the TCI, other studies have developed the Holiday Climate Index (HCI) [13,14] and computed it, in a reshaped formulation, for beach and urban destinations with climate data downscaled dynamically [31]. Other studies [8] have proposed the co-creation of specific indices for each specific activity/destination. One such study described indices for beach and snow tourism [32], while others developed indices for skiing [33,34], and still others have focused on surfing [35]. Sports tourism, based either on attending a sports event or on practicing the sport, has experienced considerable growth in the last several decades. Surfing as a tourist activity has traditionally been labeled as sports tourism [36] or nautical, maritime, or marine tourism [37]. Most recently, researchers defined it as 'blue tourism', a concept intimately related to the blue economy and the blue growth strategy [38]. Blue tourism highlights the sea as the central resource for leisure and recreation activities and leisure and tourism industries [39,40].

Surf and surfing tourism affect the environment and depend on its preservation and there is a concern regarding not only the quality of the activity but also its sustainability. New research has ranked Cape Town beaches in terms of sustainability by using surf-tourism-related indicators [41]. Similarly, other authors have used the Driving Forces-Pressures-State-Impacts-Responses (DPSIR) framework to propose indicators to measure human activities affecting surf breaks [42]. Similarly, it has been affirmed that surf breaks are finite, valuable, and vulnerable natural resources that not only influence community and cultural identities but are also a source of revenue and provide a range of health benefits [43]. Despite this, surf breaks lack recognition as coastal resources and, therefore, the associated management measures required to maintain them. It has also been recognized that conserving biodiversity and ecosystem services requires diverse models that empower communities to act steward of such resources and also to benefit from them. They investigate the potential of surfing resources and the consciousness of surfing communities as beacons of environmental and marine biodiversity preservation. In fact, the sustainable management of these resources ensures their ability to provide for the character, economy, and development of coastal communities worldwide [44]. Valencia et al. [45] studied how surfing tourism's effects are perceived by local residents; the results of their research have implications for surf tourism management at the destination.

Fox et al. [46] focused their research on recreational ocean users, specifically surfers, and how their blue space activities may inform the understanding of ocean processes and human–ocean interconnections. They presented novel insights about the opportunities for integrating ocean sustainability strategies through blue space activity mechanisms and coastal community engagement. They defined the surfing social-ecological system adapted from McGinnis et al. [47] and demonstrated how the human (social) and ocean (ecological) systems provide opportunities for interactions between surfers (users) and waves (resource units), producing ocean literacy understanding and awareness.

Another aspect that has an impact on the perception and development of surf is the safety of the practitioners. Mindes [48] analyzed hazards perceptions among surfers in Southern California. Rip currents are a primary mechanism associated with dangerous situations [49] and have been the focus of beachgoer education and awareness strategies [50]. Surfers and lifeguards often utilize rip currents to expedite their journey across the surf zone [51]. Attard et al. [52] found that 63% of surfers believe they have saved a swimmer's life. The enjoyability and safety of the surfing experience are enhanced when the right information is communicated in the right way. Boqué et al. [9] surveyed surfers in Spain to explore which meteorological and climatological information they find necessary for a better surfing experience.

De Andrés et al. [53], who studied surfers' balance during surfing activity between competitive surfers and non-competitive surfers in Somo, in collaboration with Escuela Cantabra de Surf and Somo Surf Center, defended that surfing in training and competition is characterized by a great variability of environmental factors such as different sizes and breaking shapes of the waves and changing weather conditions. Nevertheless, there are limitations and possibilities for the world surfing reserves [54] that can be assessed by surfing climatology and surfing forecasts [9].

### **3. Study Area, Data and Methods**

### *3.1. Study Area*

The pilot area of the Somo surf spot is part of the municipality of Ribamontán al Mar Municipality. Ribamontán al Mar is located on the northern shore of the Iberian Peninsula in the Cantabria region (Figure 1) close to its capital of Santander. It hosts Spain's first surfing school, established in 1991. Ribamontán al Mar (declared in 2012 as a World Surfing Reserve, the first in Spain and the second in Europe) is a pioneering territory in its commitment to surfing tourism through its Surfing Competitiveness Plan (2009–2014) and in promoting territorial balance through the competitiveness of destinations, international projection, specialization of tourism products, and deseasonalization [54].

The area is characterized by an oceanic climate, specifically Cfb, in the Köpen Climate Classification [55]. The Cfb type is defined as being temperate mesothermal, without a dry season, and with a mild summer. Using monthly values, the annual thermometric regime is regular, with the highest average values in August and the lowest in January. Precipitation is significant even in the drier months [56]. Wind variations are present throughout the year. Northwest and southeast winds dominate in the winter. In the spring, northerly winds usually blow and then shift to a northeasterly direction in the summer. High-intensity winds are more frequent in the winter and at the end of autumn [57].

### *3.2. Data and Methods*

Data for our analysis were obtained after applying the high resolution downscaled ocean waves (DOW) approach [58,59] to the global ocean waves hindcast [60] data. This hindcast is a historical hourly wave reconstruction generated with the WAVEWATCH III model [61], using the atmospheric forcing from the Climate Forecast System Reanalysis (CFSR) global reanalysis from 1979 to 2010 [62] and extended to the present by CFSv2 [63] with a ~0.2◦ resolution. GOW2 has global coverage with a spatial resolution of 0.5◦ × 0.5◦ and a resolution of 0.25◦ × 0.25◦ in zones near the coast. The DOW approach is a global framework to downscale waves to coastal areas, which takes into account a correction of open sea significant wave height (directional calibration). The approach combines numerical models (dynamical downscaling) and mathematical tools (statistical downscaling). First, a regional hindcast is numerically simulated with the Simulating Waves Nearshore (SWAN) model using high-resolution winds from the Cantabrian domain of downscaling winds (a 3 km historical reconstruction from global CFSR reanalysis) and the GOW2 spectral data as the boundary conditions.

Then, the DOW Cantabria database is used, which is based on regional waves as initial conditions for waves in the contours of high-resolution numerical domains, at ~100 m resolution.

Our methodological approach (Figure 2) used significant wave height (*Hm*0), peak period (*Tp*), wind speed (*Ws*), and wind direction (*Wd*) downscaled climate data from DOW in the Somo surf spot in the definition of a climate service for the management of *surfing destinations.* In addition, using *Hm*0 and *Tp* as input from DOW, we computed the wave energy flux (*We*) with the following formula [64]:

$$\begin{array}{l}\text{\(\prime\)}\,^2T\,p\\\text{\(\prime\)}\,^2\mathbf{\tilde{v}} = \text{wave energy}\,flux} \\\,^2H\_{\mathbf{m}0} = \text{significant\,\,wave\,\,height} \\\,^2T\,p = \text{peak\,\,wave\,\,period}\end{array} \tag{1}$$

**Figure 2.** Development workflow of the climate service for surfing destination management.

We designed the surfing management indicators by combining the variables previously described and constraining hourly data to daylight time (obtained through the R package suncalc, https://cran.r-project.org/web/packages/suncalc/suncalc.pdf) when surfing activity was concentrated. We obtained (1) a daily surf climatology, (2) a surfer-skill climate indicator, (3) an index for alternatives to surfing, and (4) a hazard climate indicator for surfers and swimmers.

Surfing climatology yields the number of expected surfing days per year, i.e., days when, following Espejo et al. [65] and Boqué et al. [35], *Hm*0 ≥ 0.5, *Tp* ≥ 6, and *Ws* < 20. Days that do not meet these requirements are considered non-surfing times. For these periods, we described and indexed combining *Hm*0 and *Ws* to suggest to surfers and surf schools the best surf-related alternatives (e.g., other water sports), according to the state of the wind and the sea. We considered a surf-related activity to be any activity requiring the use of a board. We grouped them as (1) Stand Up Paddle Surf (SUP) activities, for which waves are not required, e.g., SUP yoga, SUP Pilates on board, or a water polo match using surfboards [66]; (2) SUP activities that require waves and are similar to surfing—called SUP Wave; and (3) sports such kitesurfing, in which wind speed is the key element [67]. These activities and their optimal values of *Hm*0 and *Ws* are shown in Table 1.

**Table 1.** Alternative surf activity definition.

The second index (Table 2) categorizes the *Hm*0 values as different surf-skill levels (i.e., beginner, intermediate, advanced, or big wave rider). The values of the different intervals are an adaptation of Hutt et al. [68], who defined the maximum and minimum values of wave height according to the surfers' skills. We also combined these values for the peak period following the thresholds suggested by Espejo et al. [65].

**Table 2.** Surfing skill-oriented climatology definition.

To compute these two monthly indices from hourly observations, we used our own formula as follows:

$$I\_m = \frac{\left(\sum \text{obs}\_{\text{crm}}\right)}{\sum \text{obs}\_m} n\_m \tag{2}$$

where *Im* (Equation (2)) corresponds to the monthly indicator for a specific month and expresses the number of complete days that meet a set of given conditions, regardless of how they are distributed within the month; *obscrm* is the number of hourly observations that meet the required conditions; *obsm* is the total number of observations per month; and *nm* is the number of days in that month (e.g., 31 in January, 28/29 in February, etc.).

For the hazard indicator, we followed Attard et al. [52], who demonstrated that surfers do well in locations that can be hazardous to swimmers. In line with Attard's approach [52], we used *Hm*0, *Ws*, *Wd*, and *We*, according to formula II. Following Koon et al. [69], Mazzone [70], Whitcomb [71], and Miloshis et al. [72], we computed hazard scores for intermediate surfers, the third general degree established by the surfing Spanish federation framework, and intermediate swimmers, according to the classification of the Real Federación Española de Natación achieving the level fry 2. As swimmers' and surfers' interactions with the ocean are intrinsically different, we defined specific cut-off points for each, as reflected in Table 3, and attribute values from 0 to 4 to each condition to create a composite index that can take values between 0 and 10. Maximum values (10) relate to hazardous conditions; minimum values (0) relate to conditions without hazards.

**Table 3.** Hazard management: surfers' versus swimmers' definition.

**Table 3.** *Cont*.

We obtained each daily hazard indicator by selecting the maximum hourly value of the hazard score per day. These values were packaged (1) in the form of calendars and in graphical time series where maximum monthly values are shown, as we will present in Section 4.

For SD, SDS, and AO, we represent the monthly values as boxplots, and we also show the annual values in a graphical time series to observe the evolution for the 1985–2015 period. For all sets of indicators, the Mann–Kendall test was calculated to explore the trends. For SuS and SwS, we represent the annual mean of the monthly mean of the daily maximum value in the time series.

### **4. Results**

### *4.1. Surf Climatologies*

Figure 3 presents the monthly climatology of the expected surfing days computed from 1985–2015 at the Somo surf site. The annual number of expected surfing days was 229.5. The highest monthly value corresponded to July (22 days), followed by August (21.7 days/month) and June (21 days/month). Lower values corresponded to November (16.3 days/month), February (16.9 days/month), December (17.8 days/month), and April (17.9 days/month). The winter months (December, January, and February) showed larger interquartile ranges.

**Figure 3.** Expected distribution of surfing days per month, Somo, 1985–2015.

Figure 4 shows the evolution of the annual SD for the 1985–2015 period. The SD annual values ranged from 247.8 days (the year 2015) to 206.19 days (the year 2010). The plot shows the variation of the annual SD between the years; the standard deviation corresponded to 10.09 days.

**Figure 4.** Evolution and trend of annual surfing days; reference period is 1985–2015 in Somo.

Figure 5 adds the consideration of the surfer's skill level. Our results showed that, depending on the practitioner's skills, the season shifted from summer to winter, opening the door to the deseasonalization of tourist resorts. In this regard, the peak number of the expected days for the beginners clustered again in the summer: June (17.3 days/month), July (18.19 days/month), and August (17.2 days/month). By contrast, intermediate surfers should expect to find a larger number of optimal days in the transition seasons, with peaks in April (14.4 days/month) and September (13.4 days/month). Finally, advanced surfers and big wave riders will find better conditions in the winter. For advanced surfers, the expected days peaked in January (15.1 days) and December (12.3 days/month). Big wave riders should expect <1 day/month, concentrated throughout the period of the November–April semester and peaking in January (0.7 days/month).

Figure 6a–d show the SDS annual evolution and trend for the 1985–2015 period. The maximum SDS were detected on surfing days for intermediate surfers at 167.02 days (in 2011), followed by beginners with 157.36 days (in 1985), 108.21 days (in 1986) for advanced surfers, and 10.02 days (in 2014) for big wave riders. The minimum SDS annual values were ranked from big wave riders with 0 days (in 1992), advanced surfers with 43.16 days (the year 2010), beginners with 94.94 days (the year 2011), and intermediates with 114.5 days (in 1989). The standard deviation ranged from 2.19 days (big wave riders) to 17.41 days for advanced surfers. The case for intermediates was 11.89 days and for beginners was 16.2 days.

### *4.2. Alternative Offer*

Days when environmental conditions do not favor surfing might still be suitable for alternative water sport activities (Figure 7a–c). From the series of activities considered in Section 3, in the case of the Somo surf spot, the surf activity offered most frequently was SUP Wave (216 days/year); specifically, July (22.7 days/month) had the largest number of expected days. Kitesurfing was the alternative surf activity offered second most frequently (141.6 days/year), and the spring and summer months presented the lowest values for expected kitesurfing days per year, linked with summer's calm winds. SUP yoga (7.4 days/year) was the alternative that offered lower possibilities, which indicates that if the activity needs to be promoted, it should probably ubicate in rivers next to the main surf spot. SUP Wave and kitesurfing seemed to be complementary, as when there is so much wind to practice SUP Wave, there is enough wind to practice kitesurfing, wing, or windsurfing. The high values for these wind activities were present specifically in autumn and winter: November (15.8 days/month), December (16 days/month), and January (16.8 days/month). A good period for practicing SUP Wave is during the spring and summer, and at the beginning of autumn: May (21 days/month), June (22 days/month), July (22.7 days/month), August (22.4 days/month), and September (19.6 days/month).

**Figure 5.** Expected distribution of surfing days per month sorted by surfer's skill level; reference period is 1985–2015 in Somo.

**Figure 6.** (**a**) Evolution and trend of annual surfing days for beginner surfers; reference period is 1985–2015 in Somo. (**b**) Evolution and trend of annual surfing days for intermediate surfers; reference period is 1985–2015 in Somo. (**c**) Evolution and trend of annual surfing days for advanced surfers; reference period is 1985–2015 in Somo. (**d**) Evolution and trend of annual surfing days for big wave riders; reference period is 1985–2015 in Somo.

**Figure 7.** (**a**) Expected distribution of alternative offer monthly days for SUP-related sports; reference period is 1985–2015 in Somo. (**b**) Expected distribution of alternative offer monthly days for SUP Wave sport; reference period is 1985–2015 in Somo. (**c**) Expected distribution of alternative offer monthly days for wind-related sports, i.e., windsurfing, kitesurfing, wing surfing; reference period is 1985–2015 in Somo.

Figure 8a–c shows the annual AO evolution and trend for the 1985–2015 period. The Mann–Kendall test denoted the absence of a trend in the data. For the annual AO values, SUP-related activities presented the lowest values of annual days: a minimum of 3.35 days in 1986 and a maximum days of 11.81 days in 1997. SUP Wave presented a maximum of 207.74 annual days in 2001 and a minimum of 165.23 days in 1993. Wind and water sports such as windsurfing, wing surfing, or kitesurfing presented high maximum annual values in 2010, corresponding to 138.71 days, and lower values were in 1998, corresponding to 102.89 days.

**Figure 8.** (**a**) Evolution and trend of annual alternative offer days for SUP-related sports; reference period is 1985–2015. (**b**) Evolution and trend of annual alternative offer days for SUP Wave sport; reference period is 1985–2015. (**c**) Evolution and trend of annual alternative offer days for wind-related sports, i.e., windsurfing, kitesurfing, wing surfing; reference period is 1985–2015.

### *4.3. Hazards Management for Surfers and Swimmers*

As expected, the results showed that, in the coordinates of the Somo surf spot, the hazard score was higher for swimmers than for surfers (Figure 9). The maximum possible values were 10 for both swimmers and surfers, and even so, at any time of the studied period, a score of 10 was reached. The scores for surfers were always lower than those for swimmers (Figure 9). Higher hazard values were present in the winter, autumn, and spring; lower values corresponded to the summer season. After analyzing higher scores for surfers versus swimmers year round, we found the following values: January (4.1 vs. 7.3), February (4.2 vs. 7.3), March (3.9 vs. 7), April (3.7 vs. 6.7), November (4.4 vs. 7.8), and December (3.9 vs. 7).

**Figure 9.** Distribution of swimmers' and surfers' hazard score, 1985–2015: Somo surf spot.

Figure 10a,b presents the evolution and trend of the annual values of SwS and SuS for the 1985–2015 period. The highest values for SwS and SuS were in 2014 (a score of 9.21 vs. 7.07) and the lowest happened in 1987 (a score of 7.32 vs. 4.25).

The Mann–Kendall test denoted the absence of significant trends in the series of all the indicators, characterized by interannual variability.

### **5. Discussion**

As described in Section 3, surfing days were computed considering peak period (*Tp*), significant wave height (*Hm*0), wind direction (*Wd*), and wind speed (*Ws*) parameters. The highest values in the summer will probably be linked to the period of calm winds in the area. Nevertheless, the months in the winter that presented lower values will probably present high values in other spots of the east of the beach where the wind speed is not as high as in this region due to orientation and exposure factors. These results improved those of Boqué et al. [35], who calculated expected surfing days without considering wind direction and wind speed, basing their calculations only on buoy data information from *Puertos del Estado* and *Instituto Marinha Portugal*.

As Scarfe et al. [73] suggested, we have developed a surfing wave climatology intended as an information resource for surfing management. Espejo et al. [65] developed a global index for analyzing surfing climatic potential, but the horizontal spatial resolution of ocean data was coarser than ours. Espejo et al. [65] based their analysis on a global scale, while we focused on the local scale by utilizing downscaled data with a hybrid method. Tausía [74] studied the surfing conditions in the Somo surf spot with a slightly coarser spatial resolution of 100 m, focusing on the numerical simulation of the physical processes that affect surfing waves.

Advanced surfers had a higher number of expected days per month from October to April. Intermediate surfing days per month had fewer fluctuations year round. As suggested by Hutt [68], surf breaks were classified according to surfing skills. In this sense, we followed Barlow et al. [75], who examined the effect of wave conditions and surfer ability on performance and the physiological response of recreational surfers. Hence, by combining climatic conditions and surfing levels as defined by Hutt [68], we see that we can contribute to the knowledge about expected surfing days by considering surfers' skills. Thus, we have more evidence about how different sizes of waves are associated with the balance of surfers during surfing activities, which will depend on surfers' skills as De Andrés et al. [53] stated.

These results provide important insights into demonstrating the different capacities for offering water-related activities for a specific territory. In some cases, lectures on the deseasonalization of the tourist activity are supported by the offer of other kinds of tourist products. Peñas de Haro [76], defended deseasonalizing sun and beach tourism in Mallorca, which is typically concentrated in the summer months. The deseasonalization proposal is based on the offer of surfing and body surfing activities, as these activities are possible when sun and beach climatic requirements are not in their best conditions. Martín et al. [77] also presented a proposal for the diversification of products in consolidated tourist destinations, giving special mention to the possibility of promoting Costa del Sol as a surfing destination. Even so, these studies did not specifically analyze climate data to determine the exact climatology of the products that can diversify the tourist offer, which is one of the aims of our study.

Regarding the hazard information from swimmers, as stated by Short et al. [78], rip currents and beach hazards have an impact on public safety and have implications for coastal management. We believe that surfers and lifeguards can assist swimmers in a hazardous situation and that swimmers should have lessons on rip current escape strategies [72]. In the event that a swimmer does not know how to escape from a rip current, surfers and lifeguards, who know how rip currents work [50], can perform a rescue [51]. Surfers possess this ability because they usually use rip currents to arrive at the surfing waiting-area zone for surfing [50]. Therewith, we consider in which moments surfers present the highest hazard score because, in that situation, they are not going to be able to rescue swimmers. During these times, lifeguards should check on both surfers and swimmers. Based on climatic conditions, our results reveal the difference between swimmers' and surfers' hazards, and thus, this information can assess lifeguards' decision making related to which periods are better for assisting only swimmers and which are important for assessing the safety of both swimmers and surfers. In Somo, lifeguards are only present during the summer months; therefore, this information can be of value when deciding whether to extend the period of lifeguards' presence if required.

### **6. Conclusions and Perspectives**

León et al. [79] explained that the tourism sector is recognized as being highly vulnerable to climate change, and research supporting destinations to enhance their resilience capacities is still considered scarce. As Bradshaw [80] found, a review of the related tourism literature raises awareness of surfing as a sport, tourism, and innovation opportunities for policymakers in the context of a highly entrepreneurial country, highlighting the benefits that surf tourism offers for sustainable growth and positioning surf tourism as an innovative product.

Our research represents an advance in the knowledge of (1) the expected surfing conditions, (2) the expected surfing conditions related to surfers' skills, (3) the expected conditions for alternative surf offers, and (4) the expected hazard conditions and their differences for surfers and swimmers. Our case is applied in Somo's surf spot but the general framework can work as a model for other specific surfing destinations, specifically sandy beaches. Surfing destinations with point breaks and estuaries propagations of swell should follow another approach; nevertheless, surfing management indicators can be applied in the same way.

Following Borne [81], who defended the functions of academic and more-popular literature within different language games, academic accounts can seem turgid, dense, and overcomplicated, while popular media may sometimes be seen as repeating banal and superficial observations. However, the scope for surfing-related authors to seek to bridge the gap between scholarship and surfing culture is exceedingly broad. For this reason, we developed specific indicators and represented them to assist surfing destination managers to be better prepared to make climate-smart decisions as recommended by the Global Framework for Climate Services [2]. In this vein and following Kumar et al. [82], who explored how the visualization and communication of the forecast support the end users' decision making, our graphics in the results section are designed to be simple and easy to interpret for surfing destination managers, surf schools, and surfers, among others.

Our results contribute to the blue economy knowledge, as Spinrad [83] highlighted that the new blue economy is realized as the commercialization of value-added data, information, and knowledge about the marine environment. The economic benefits are enabled by dramatic improvements in observational capabilities and the development of predictive models. Increases in the volume, diversity, and quality of data, as well as more skillful methods of forecasting and nowcasting, make possible the production of products and services enhancing traditional components of the blue economy.

Surf tourism development provides economic opportunities to residents in coastal destinations, yet it has also been criticized for associations with gentrification, pollution, and inequality. The pandemic exacerbated existing sustainability challenges by accelerating development near surf breaks in Bocas del Toro, Panama. Mach [84] also found that there is an urgent need for stakeholders in surf communities, and particularly surf tourism business owners, to cooperate to preserve surf experiences that are vital to residents' mental and physical health and well-being as well as attractiveness as a surf tourism destination. As Mach et al. [85] explained, we defend the idea that surfing tourism deserves a more significant place in funding initiatives, discussions, and research related to fostering sustainable development from ocean resources in the rapidly changing world.

Our research can modestly contribute to Spain's goals for its Sustainable Tourism Strategy 2030. This is because, in 2019, the general guidelines of the Sustainable Tourism Strategy were presented, but surfing tourism was not mentioned.

This study presents a foundation for surfing climate service surfing. Future work will apply our indices to other surf spots and will validate the predictability of the indices. In addition, more indicators can be generated to assess surfing activities if more variables are added; an example is wetsuit recommendations if seawater temperature is analyzed. The present study has focused on surf tourism, but the methodology can be applied to other outdoor and sport-tourism-related activities following Silva et al. [86] and other dimensions of adventure tourism [87].

As surfers have their experiential standards for the surfability of particular places and conditions, and following Hutt et al. [68], research can affirm that, depending on surfing skills, surfers will be able to perform in specific meteo-oceanic conditions or not. The general idea is that the advanced surfers can surf in all conditions when they are not adverse. Conversely, beginning surfers cannot perform in all situations. Nevertheless, when high waves that are beneficial for advance surfers occur, beginners may sometimes also surf, but not in the same area. Advanced surfers will surf in the green wave area and beginners will surf in the white water area. The standards of surfers will depend on the level of practice, i.e., beginner, intermediate, advanced, and big wave rider, and on style, i.e., body board, skim, shortboard, longboard—for this reason, in general terms, some beaches are better for beginners and others for advanced surfers. Even so, as meteo-conditions

are constantly changing, there is no general surf clue that can help the surfing community. For this reason, the present research has focused on developing those different needs identified from the survey profiling different kinds of surfers: beginners, intermediates, advanced, and big wave riders [9]. Relatedly, future research may explore the provision of an app with reactive programming for surfers that could help them to set preferences for meteo-oceanic variables.

Future research may also explore the needs of actual resort managers and/or developers by means of focus groups, adapting Font et al.'s [8] methodology to better re-design a climate service. The development of this kind of research will promote the maximization of the usage of surfing resources.

Research has explored the advances in climate services in multiple fields but determining a climate service for surfing destination management through downscaled wave data with a 100 m horizontal spatial resolution has not been done before. Further research may focus on developing the same/similar indicators but while also combining surfing forecasting with the downscaling method employed in the present research. This forecast data would help destination managers formulate better marketing plans and development. The next steps of the investigation can apply the computation of the same indicators with projection data considering the different climate scenarios to study how surfing resources will change in the future.

**Author Contributions:** Conceptualization, A.B.C., M.M., M.S.B. and E.A.; methodology, A.B.C., M.M., M.S.B. and E.A.; software, A.B.C., M.M. and M.S.B.; validation, A.B.C., M.M., M.S.B. and E.A.; formal analysis, A.B.C., M.M., M.S.B. and E.A.; investigation A.B.C., M.M., M.S.B. and E.A.; resources, A.B.C., M.M., M.S.B. and E.A.; data curation, A.B.C., M.M., M.S.B. and E.A.; writing—original draft preparation, A.B.C.; writing—review and editing, A.B.C., M.M., M.S.B. and E.A.; supervision, A.B.C., M.M., M.S.B. and E.A.; funding acquisition, A.B.C., M.M., M.S.B. and E.A. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research is within the INDECIS project (INDECIS is part of ERA4CS, an ERA-NET initiated by JPI Climate and funded by FORMAS (SE), DLR (DE), BMWFW (AT), IFD (DK), MINECO (ES), and ANR (FR) with co-funding by the European Union Grant 690462). This article publication was possible with the support of the Secretaria d'Universitats i Recerca del Departament d'Empresa i Coneixement de la Generalitat de Catalunya, the European Union (UE), and the European Social Fund (ESF) (Doctoral Research Grant 2021FI\_B2 00147—Formació personal investigador novell).

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** The data presented in this study are available on request from the corresponding author.

**Conflicts of Interest:** The authors declare no conflict of interest.

### **References**


Contents

Preface

This book contains well-written monographs within the broad spectrum of applied mathematics, with the aim of offering an interesting reading of current trends and problems in this fascinating and critically important field of mathematics to a

broad category of researchers and practitioners. Recent developments in high-performance computing are radically changing the way we do numerics as applied mathematicians. Because of the impressive advances in computer technology and the introduction of fast methods that require less algorithmic cost and fewer memory resources, nowadays a rigorous numerical solution of many difficult computational science applications has become possible. In the future we will be solving much bigger problems, and even more factors will need to be considered than in the past when attempting to identify the optimal solution approach. The gap between fast and slow algorithms is rapidly growing. Methods that do more operations per grid node, cell, or element, such as higher-order and discontinuous Galerkin discretization schemes and spectral element methods, are becoming very

attractive to use against more traditional techniques such as finite element

an industrial setting.

discretization schemes. Structured data are already coming back, because they may achieve a better load balance than unstructured grids on computers with hundreds of thousands of processors. Novel classes of numerical methods with reduced computational complexity will need to be found to solve large-scale problems arising in

The book is structured in three distinct parts, according to the aims and methodologies used by the authors in the development of their studies, ranging from optimi-

zation techniques to graph-oriented approaches and approximation theory, providing overall a good mix of both theory and practice. Chapters 1–2 present an overview of unconstrained optimization techniques, covering both line search and trust-region methods that are essential ingredients to guarantee global convergence of descent schemes. Numerical optimization is the primary tool used in Chapter 3 to analyze the shape factor of exceedance probability curves, which is a critical analysis tool to assess risks, e.g., in the study of natural disasters such as floods, hurricanes, and earthquakes. Chapters 4–5 describe graph-oriented approaches. Chapter 4 develops a graph-based model for the topological design of the wide area network using dynamic programming and dynamic programming with state-space relaxation methodologies. Chapter 5 uses graph and subgraph models to speed up the computations of scalar multiplication algorithms on elliptic curves defined over finite fields, which is one central and time-consuming operation in elliptic curve cryptography. Finally, the contributions of the last two chapters deal with some aspects of functional approximation. Chapter 6 proposes a study of different forms of bounded variation sequence spaces of invariant means with the help of ideal operators and functions such as Orlicz function and modulus function. The results show the potential of the new theoretical tools to deal with the convergence problems of sequences in sigma-bounded variation occurring in many branches of science, engineering, and applied mathematics. Chapter 7 is devoted to an overview of the mathematics of special polynomials showing how to obtain them in a simple and straightforward approach using basic linear algebra concepts. Overall, the collection

of contributions demonstrates the highly interdisciplinary character of the