Scientific Literacy to Address Sustainability: A Study on Deep-Sea Mining Education with Adolescents from a Social Care Institution

Abstract

Pursuing sustainable development is increasingly urgent due to resource depletion and environmental degradation, compounded by the need for a green energy transition requiring significant mineral resources. Traditional mining practices result in several environmental impacts, prompting the exploration of alternatives, like mining the ocean floor. This method offers a potentially less invasive way to obtain critical minerals. Notwithstanding, our understanding of the ocean ecosystem, which is crucial to Earth’s life support system, is still too limited. This study aimed to assess an educational intervention on sea mining for polymetallic nodules while improving scientific literacy and system thinking and supporting Sustainable Development Goals (SDG) 4, 13, and 14. A pre-/post-intervention design was implemented with 17 adolescents (aged 12–16 years) from an underprivileged non-formal context. The mixed-methods approach involved role-playing and modelling activities focused on the question: “Do you agree with mining polymetallic nodules in deep-sea waters”? The Wilcoxon test revealed that the intervention changed participants’ opinions about the theme, showing a statistically significant difference in student responses before and after the intervention (Z = −2.165; p = 0.030). A content analysis showed enhanced argumentation, understanding of Earth’s subsystems, and decision-making abilities. These findings suggest that the educational resource positively impacted students’ scientific literacy on the topic. This approach can be extended to other contexts and inform future investigations.

1. Introduction

The growing demand for natural resources, driven by global population growth and the transition to green energy, poses significant challenges to sustainable development. As the world seeks to reduce its reliance on fossil fuels, there is an increasing need for minerals critical to renewable energy technologies, such as solar panels, wind turbines, and electric vehicle batteries [1]. To meet growing demand, mining must continue for the foreseeable future [2,3,4,5]. However, traditional terrestrial mining practices, including extraction, processing, and waste disposal, cause severe environmental degradation, such as habitat destruction, water contamination, soil erosion, and loss of biodiversity, which have detrimental effects on ecosystems and human health [6,7]. These practices can also displace local populations, exacerbating social and economic challenges [5]. Moreover, the theme is entailed by geopolitical concerns regarding some of the critical metal supply chains. For instance, China is responsible for 95% of total rare earth elements (REE) [4], and the Democratic Republic of Congo, a country recognised for poor working conditions and child labour, is responsible for more than 60% of cobalt production [5,8,9]. According to the Organisation for Economic Cooperation and Development [6], the increased use of critical metals is expected to cause these impacts to double between 2017 and 2060. As a result, in addition to developing more efficient recycling technologies, there is an urgent need to explore alternative sources of these essential minerals. One such alternative is deep-sea mining (DSM) [3,9,10]. According to several authors, this presents a potentially less environmentally invasive method of obtaining critical materials necessary for modern technologies [1,11,12,13]. However, it poses many challenges. The ocean is a complex and largely unexplored environment [14,15], and the full ecological impact of and timescale of recovery from mining in these regions are not yet fully understood [1,16,17,18,19,20]. Therefore, any discussion of mining the seafloor must be informed by a solid understanding of the scientific, social, and ethical considerations involved.

Deep-sea mining is a prime example of a socioscientific issue (SSI), which refers to complex, real-world problems involving scientific concepts and social dimensions. SSIs typically require the consideration of ethical, environmental, economic, political, and societal impacts and often lack clear-cut solutions [21,22,23]. These characteristics make SSIs particularly challenging and valuable for educational settings, as they encourage critical thinking, debate, and the integration of knowledge across multiple disciplines.

It is not enough for individuals to possess knowledge of scientific facts; they must also be able to apply it to make informed decisions about complex themes [24]. This ability to engage with scientific questions critically and thoughtfully is particularly important for adolescents, who will become decision-makers in the future. Concerning environmental issues, scientific literacy empowers young people to participate actively in society, advocating for sustainable practices and considering immediate and long-term environmental impacts [21,25]. As argued by Osborne and Allchin [26], science education must equip students to become “competent outsiders”—non-experts who possess enough knowledge of and about science to assess the credibility of information and justify their trust in science-related matters. Thus, science education for responsible citizenship should include activities that provide students with ways to solve and discuss socioscientific issues from various perspectives [27]. A systematic literature review about SSI [28] underscores the need to align SSI teaching topics with current real-world issues to achieve its learning outcomes. At the same time, a recent work by Zeidler and Sadler [23] states that “out-of-the-school arenas” are necessary educational settings for addressing SSI, underscoring the importance of non-formal activities.

Addressing the current global context, the European Commission (EC) developed a framework for building competencies that can empower individuals to act sustainably, including, among others, (i) critical thinking, defined as evaluating information and arguments, recognise underlying assumptions, questioning, and considering how personal, social, and cultural backgrounds shape thoughts and conclusions; (ii) systems thinking, described as tackling a sustainability problem from multiple perspectives, taking into account time, space, and context to grasp how different elements interact both within and across systems; and (iii) adaptability, presented as the ability “to manage transitions and challenges in complex sustainability situations and make decisions related to the future in the face of uncertainty, ambiguity and risk” [29]. Acknowledging the relevance of achieving this goal, the EC also recognised the urgency of developing these competencies in all types of educational programmes, from formal, non-formal, and informal learning environments, helping learners to acquire these skills from early ages and throughout life.

This study integrates sustainability education with deep-sea mining (DSM) complexities by employing an innovative combination of two well-known teaching strategies: role-play and modelling. These were designed to enhance scientific literacy, systems thinking, and decision-making skills, equipping students to critically analyse the trade-offs between resource use and environmental impact. Such an approach aligns with the UNESCO Decade of Ocean Science for Sustainable Development [14], emphasising the importance of sustainable practices and informed decision-making in ocean-related activities.

The investigation seeks to contribute to educational strategies that support the SDGs, particularly SDG 4 (Quality Education), SDG 13 (Climate Action), and SDG 14 (Life Below Water).

1.1. Deep-Sea Mining: A Sustainable Alternative to Tackle Climate Change?

The ocean is the largest ecosystem on the planet, covering more than 70% of the Earth’s surface [15,30]. It plays a crucial role in supporting life on the planet, as it provides a wide range of ecosystem services vital for human well-being and environmental stability [16,17,31,32]. Some examples are listed below.

• Provisioning services, such as food, medicinal and genetic resources, raw materials, and transportation.
• Regulation services, including climate regulation, climate change mitigation (CO₂ sequestration), pathogen regulation, and natural hazards mitigation.
• Supporting services, like habitat creation, biodiversity maintenance, nutrient cycling, and primary production.
• Cultural services, comprising tourism, recreational activities, spiritual and personal well-being, and education.

Despite advances in science and technology, our understanding of the ocean, particularly its deepest regions, remains limited [1,17,33,34].

Massive population growth, changes in human consumption patterns, and the need to move toward planetary sustainability have led to an enormous increase in demand for minerals. This puts significant pressure on the mining sector, particularly concerning minerals essential for the green energy transition, such as copper, nickel, cobalt, lithium, graphite, and rare earth elements [9,35,36].

The abundant occurrence of vital minerals on the ocean floor has been known for over a century [37]. Mining the seafloor refers to their exploration and exploitation. These mineral resources are found in hydrothermal vents, cobalt crusts, and polymetallic nodules (PMN). The latter resemble potato-sized nodules and are rich in minerals such as nickel, cobalt, manganese, and copper [1,10,38]. Due to their high economic and industrial potential and abundance on the sea floor, PMN are the most important in underwater mining [9]. For this reason, they have been the subject of several studies for possible large-scale exploitation for some decades [37]. The distribution area of commercially significant concentrations of these nodules has been documented in the Mid-Indian Ocean Basin and several Pacific areas [20]. In the Clarion-Clipperton Zone (CCZ), located in the Northeast Pacific, it is estimated that there are 21 billion dry tons of these nodules, with many elements surpassing terrestrial reserves [39].

Although it is seen as a driving force for the economic development of the maritime sector [39], current knowledge about the impact of deep-sea mining exploitation is still at a very early stage of development [18,33,34,40,41,42,43]. Current technologies for PMN mining typically use hydraulic dredging systems. These involve collectors operating on the seafloor to gather nodules using water jets or rakes. Once collected, the nodules are separated from the sediments on the seabed and transferred to the surface using risers or airlift pumping systems. After extraction, excess sediment is discharged back into the ocean. Although this technology minimises deeper seabed penetration and primarily targets nodules embedded in the upper cm of sediments, gathering the nodules disturbs top sediment layers and, at the end of the process, the discharge of sediments generates sediment plumes [18].

Despite the harsh conditions of low temperatures, total darkness, limited food supply, and extreme pressures, this vast ecosystem exhibits remarkable biodiversity. It hosts a wide range of species, including microorganisms such as chemosynthetic bacteria, along with corals, sponges, crustaceans, vertebrates, and many others [10,19]. Possible damage caused by DSM includes direct and indirect biodiversity loss, seafloor habitat disruption, the rise of sediment plumes and sediment compaction, noise pollution, and carbon cycle impact [1,13,18,33,34,41]. In addition, some authors argue that no information on baseline parameters could provide a suitable reference for the future comparison and analysis of the necessary recovery efforts [17]. Furthermore, this biodiversity loss will likely persist far beyond human timescales due to these impacted ecosystems’ extremely slow natural recovery rates [40,42], and modelling studies regarding the theme have focused on seafloor plumes and benthic deposition but often neglect to consider the three-dimensional propagation and temporal persistence of plumes in the intermediate waters, which also hold a significant amount of biodiversity [33].

The International Seabed Authority (ISA) was established in 1994 under the United Nations Convention on the Law of the Sea (UNCLOS) to oversee the sustainable use of deep-sea resources while safeguarding the marine environment. Its mandate is to regulate and mitigate the potential environmental impacts of DSM, particularly in areas beyond national jurisdiction [40,41,42,44,45]. These international seabed areas are designated as the “common heritage of mankind”, requiring that their resources be managed for the benefit of all humanity, focusing on equitable access, sustainable use, and environmental protection [44]. The ISA has already issued 30 exploration contracts to 21 entities to assess deep-sea mineral resources. Exploration activities generally involve geological surveys, resource evaluations, and environmental impact assessments, which typically have minimal impact. Additional activities may include developing and testing mining technologies and mineral processing techniques [46,47]. For the past decade, the ISA has been working on a comprehensive “Mining Code”—a framework of rules, regulations, and guidelines for exploitation. Its presentation is already delayed and is expected to be finished and presented in the near future. All the preliminary exploration studies carried out in the last decades have contributed to a significant amount of data and knowledge about the deep sea [45]. However, critics argue that the current ISA’s regulatory approach relies heavily on mining companies’ self-governance, creating conflicts of interest and limiting external oversight [48].

Mankind should establish optimal mining practices from the beginning. Given that exploitation activities have not yet begun, as claimed by Hallgren and Hansson [3], we find ourselves at a crossroads. Could the deep sea’s vast and rich mineral resources be harnessed to contribute to planetary sustainability, or does DSM risk depleting an invaluable resource that remains largely unknown?

1.2. Non-Formal Education: Combining Role-Play and Modelling Activities to Enhance Scientific Literacy on DSM

Non-formal education refers to organised educational activities, mainly outside the formal education system, that are often focused on skill development, personal growth, and community participation. These educational activities are typically more flexible, learner-centred, and context-specific than formal education, allowing diverse learning environments like workshops, community or after-school programmes, or online courses [49,50,51]. According to Eshach [52], non-formal education can help individuals learn, appreciate and develop positive feelings towards science. These educational contexts allow a more holistic learning experience, impacting positively learning’s cognitive, emotional, social and behavioural aspects [50,52].

Furthermore, the EC [49] also highlights the value of non-formal learning environments, particularly in science education, to promote engaged and participatory citizenship. Thus, non-formal education provides a valuable educational setting for addressing SSI teaching, as sustained by [23], and developing competencies aligned with sustainability, as indicated by Ribeiro and Vasconcelos [53] and Wals and collaborators [54]. In addition, several authors recognise that SSI teaching still creates many challenges for teachers [23,55,56,57], reinforcing the importance of building educational resources to address these vital societal problems.

The intervention was structured around two key activities: a role-play debate and a modelling exercise. These strategies are widely implemented across all student levels [58,59,60,61,62,63,64] and even in adult training programmes [59] due to their adaptability and proven effectiveness. The role-play format was chosen for its ability to actively engage students by immersing them in different perspectives, fostering engagement and critical thinking, and enhancing decision-making skills [58]. By adopting specific roles, students are encouraged to analyse information, evaluate diverse viewpoints, and construct coherent arguments. Research underscores role-play as an effective pedagogical strategy in science education, particularly for enriching students’ understanding of SSI [59,60]. Moreover, it creates a dynamic, interactive environment where students can practice scientific argumentation—a critical component of scientific literacy—which involves applying scientific concepts to make well-informed decisions about complex, real-world challenges [28]

The modelling activity aimed to deepen participants’ understanding of the broader environmental impacts of DSM, particularly its effects on the ocean ecosystem and the interconnected subsystems that can be directly and indirectly affected by the procedure. This activity was grounded in constructivist learning theory, which posits that learners build knowledge through active engagement and connecting new experiences with prior knowledge. The educational value of modelling in science education is well-documented. Scientific models are used to predict phenomena and test hypotheses, and modelling allows students to directly explore scientific phenomena that are difficult to observe, enhancing their conceptual understanding [61,62]. Thus, using models in the classroom enables students to restructure their previous mental models or build new ones, allowing for conceptual change. For this reason, it is a powerful tool for detecting and changing misconceptions [61,63]. A recent study by Ke and collaborators [64] indicates that integrating modelling practices into SSI learning prepares students to think critically about complex societal issues, fostering knowledge and informed decision-making, thereby promoting scientific literacy.

The United Nations established the Decade of Ocean Science for Sustainable Development (2021–2030) as a global initiative to foster scientific knowledge, innovation, and collaboration to protect and sustainably use the world’s oceans [65]. The Sustainable Development Goals Report 2024 [66] highlights that the world is significantly off track in achieving the tracks of the 2030 Agenda. As both a goal and the cornerstone of all others, education must go beyond merely imparting knowledge. It should focus on fostering essential life skills, such as systems thinking, problem-solving, and collaboration, which are vital for thriving today.

A key aspect of this effort is enhancing scientific literacy, which encompasses the knowledge of scientific concepts and the skills necessary for informed decisions and sustainable actions [67,68]. By equipping students with the ability to analyse evidence, evaluate trade-offs, and understand complex systems, scientific literacy empowers them to address global challenges like climate change, resource depletion, or public health crises.

Several authors recognise the value of geosciences and biology in fostering systems thinking. While the first provides valuable insights into the Earth’s subsystem interactions [69,70,71], the latter reveals the intricate connections within ecosystems [72,73]. Together, these disciplines form a comprehensive framework for understanding and addressing the complexities of sustainability challenges. Educational research is pivotal in supporting teachers by providing practical tools and strategies to develop these competencies. As “change agents” [74], they have the crucial mission of contributing to developing future citizens prepared to act for a more sustainable and equitable future. Some authors indicate that SSI teaching methods and strategies usually emphasise practices that reflect how science is applied in society through inquiry, argumentation, and role-playing rather than resorting to other scientific practices like laboratory work or modelling activities [28]. Thus, this investigation presents an innovative approach to teaching DSM by using an educational resource that combines role-play and a modelling activity.

Sustained on this theoretical background, this study analysed the effectiveness of an educational intervention focused on DSM in improving participants’ scientific literacy and systems thinking. This study was conducted with 17 students aged 12–16 from a social care institution with an underprivileged social context. The intervention was designed to engage students in role-playing and modelling activities, encouraging them to explore the question, “Do you agree with mining polymetallic nodules in deep-sea waters”?

2. Materials and Methods

This research used a mixed-methods approach to assess the effectiveness of an educational intervention aimed at enhancing scientific literacy and systems thinking related to DSM. It is part of a larger case study investigation, which is still ongoing. This study took place in a non-formal educational setting at a social support institution in a disadvantaged urban area in northern Portugal. It comprised five one-hour sessions for a total of five weeks.

2.1. Sample

A convenience sample of 17 participants (n = 17) who attended the institution after their school time voluntarily agreed to participate in this study. The sample demographic characterisation is presented in

Table 1. Sample characterisation.

Demographic Data		Participants (n = 17)
		N	%
Gender	Female	11	64.7
	Male	6	35.3
Grade level	Middle (7th to 9th)	13	76.5
	Secondary (10th or 11th)	4	23.5
Age	Mean	13.6
	Standard deviation	1.4

.

Participants were primarily female (n = 11; 64.7%), and the average age was 13.6 (the minimum age was 12, and the maximum age was 16). Most were in middle school, between 7th and 9th grade (n = 13; 76.5%), and only four were in secondary grade levels, 10th or 11th grade (n = 4; 23.5%). There were no senior high school participants. Although the number of participants was small, all target-age students available for at least one of the two weekly hours allocated for the non-formal sessions participated in the intervention, corresponding to 85% of all target-age students attending the institution.

2.2. Data Collection Instrument

According to the literature, data collection instruments, such as tests or questionnaires, should be short and clear and have easy-to-answer questions [74,75]. At the time of the intervention, the research team had already been working with the participants for a few weeks, so they were already familiar with their particularities, especially regarding their difficulty in answering lengthy collection instruments with complex questions.

To accommodate this profile and maximise the response rate, the authors deliberately applied a small test with only two questions: (1) Do you agree with mining polymetallic nodules in deep-sea waters? (2) Please justify your answer. The instrument was validated by three education experts, two science educators, and one psychopedagogy specialist. Quantitative results were analysed using IBM SPSS Statistics^© version 29, and a content analysis grid was used to analyse answers to the open question (

Table 2. Content analysis grid for the open question.

Category	Subcategory	Code
No justification.	A1. Does not present any justification.	JA
Benefits of DSM.	B1. Refers to the need to increase the production of electric cars	JB1
	B2. Indicates the need to increase the production of green energy	JB2
	B3. Mentions the need to reduce fossil fuel and increase green energy production	JB3
Challenges/Disadvantages of DSM.	C1. Refers to the death of fish	JC1
	C2. Mentions of negative impacts on aquatic living beings	JC2
	C3. Indicates negative impacts on habitats and living beings	JC3
	C4. Points out the fear of future consequences.	JC4
	C5. Refers to disturbances in two of the subsystems of the Earth.	JC5
	C6. Mentions disturbances in four of the subsystems of the Earth	JC6

).

2.3. Procedure

The research procedure followed three sequential phases (Figure 1):

• Pre-intervention phase: Participants began by viewing a documentary video (only the first three minutes on DSM [76]) that provided an overview of the global race for critical minerals. This video served as a foundation for subsequent discussions and activities designed to enhance scientific literacy and systems thinking related to the topic. Then, participants answered the pre-test questions, with an average response time of five minutes.
• Intervention phase: This phase comprised two different activities: a role-play activity and a modelling activity. Regarding the role-play activity, the participants were divided into groups of three or four elements, each representing a different stakeholder in the DSM debate. The groups included representatives of fishermen, CEOs of terrestrial mining companies, CEOs of DSM companies, environmentalists, and members of the International Seabed Authority (ISA). Each group had three or four elements and was tasked with investigating the DSM theme from their assigned role’s perspective, critically analysing relevant information, and preparing for a debate in which they had to present their group’s position and arguments. Starting with the initial small documentary video shown to the participants, they gathered into groups to prepare for the debate, with access to a computer and mobile phones that they could use for research. They were given 50–60 min to gather information and prepare their arguments for the debate, followed by 40 min dedicated to the debate itself. The teacher acted solely as a moderator. The modelling activity used easily accessible materials, including a fish tank, black beads (to represent the nodules), a mixture of sand and clay (to simulate the seafloor sediment), and an aquarium siphon (to represent the deep-sea mining equipment). he assembly of the device and further details on both activities can be found in Appendix A,

  Table A1. Groups formed for the role-play activity.

  Role-Play Activity (45′ + 60′):
  Groups (3/4 elements)	Group of fishermen
  	CEOs of terrestrial mining companies
  	CEOs of DSM companies
  	Environmental scientists
  	Members of the International Seabed Authority

  and

  Table A2. Materials necessary for the modelling activity.

  Modelling Activity (60′)
  Materials	aquarium or transparent bowl
  	sand and clay
  	black beads
  	manual siphon for cleaning aquarium
  	aquarium decorations

  , and Figure A1.
• Post-intervention phase: This phase corresponded to the post-test answering and lasted an average of eight minutes. It took place one week after the intervention phase.

3. Results

Participants’ answers to the test’s first question: “Do you agree with mining polymetallic nodules in deep-sea waters?” are presented in

Table 3. Participants’ answers to the question, “Do you agree with mining polymetallic nodules in deep-sea waters?”.

Answer	Pre-Test		Post-Test
	n	%	n	%
No.	5	29.4	10	58.8
Yes.	6	35.3	5	29.4
I don’t know.	6	35.3	2	11.8

.

An analysis of the data presented in Table 3 revealed a change in participants’ attitudes toward DSM. Pre-test responses were divided, with five participants (n = 5; 29.4%) opposing DSM, six (n = 6; 35.3%) in favour, and six (n = 6; 35.3%) expressing uncertainty (“I don’t know”). Post-test responses, however, demonstrated a significant increase in opposition to DSM (n = 10; 58.8%), a decrease in support (n = 5; 29.4%), and fewer participants remaining undecided (n = 2; 11.8%). A Wilcoxon test confirmed a statistically significant response change (Z = −2.165, p < 0.05).

The second question, “Justify your answer”, had an open-ended typology and was analysed using a content analysis grid (see Table 2). The results of this question are presented in

Table 4. Results related to the content analysis of the pre- and post-test open question, “Justify your answer” (n = 17).

Category	Subcategory	Code	Pre-Test		Post-Test
			n	%	n	%
No justification.	A	JA	9	52.9	2	11.8
Benefits of DSM.	B1	JB1	2	11.8	1	5.9
	B2	JB2	1	5.9	1	5.9
	B3	JB3	0	0.0	3	17.6
Challenges/Disadvantages of DSM.	C1	JC1	2	11.8	0	0.0
	C2	JC2	1	5.9	2	11.8
	C3	JC3	1	5.9	4	23.4
	C4	JC4	1	5.9	0	0.0
	C5	JC5	0	0.0	2	11.8
	C6	JC6	0	0.0	2	11.8

.

As indicated in Table 4, in the pre-test, more than half of the students did not justify their answer (JA, n = 9; 52.9%), while in the post-test, the number of participants who did not justify their answer decreased to only two (JA, n = 2; 11.8%).

Among those who agreed with DSM in the pre-test, justifications included the construction of electric vehicle batteries (n = 2; 11.8%) and transitioning to green energy (n = 1; 5.9%). Post-test responses reflected similar arguments, with one participant mentioning the necessity for electric vehicle batteries (n = 1; 5.9%) and another referencing the green energy transition (n = 1; 5.9%). Three other participants combined these arguments, emphasising both the need for critical minerals and reducing fossil fuel dependency (n = 3; 17.4%). For example, one participant stated that [P17] “We need these minerals to achieve more green energy and reduce the use of fossil fuels. This is necessary for a more sustainable planet”.

On the other hand, for those opposing DSM, pre-test justifications included the death of fish (JC1, n = 1; 5.9%), effects on aquatic living beings (JC2, n = 2; 11.8%), negative impacts on the ocean system, including habitats and living beings (JC3, n = 1; 5.9%), and the fear of possible negative consequences due to a lack of sufficient knowledge about the deep ocean (JC4, n = 1; 5.9%). Answers like [P2] “It will provoke the rise of a sediment plume causing the modification of that habitat and also cause the direct killing of living beings in the sea floor” were included in code JC3, whereas another response, [P6] “However many benefits it may bring, nobody knows what could happen in terms of damages … firstly it is better to study the ocean more”, was coded in JC4.

Concerning the post-test, the different justifications mentioned by participants are as follows: impact on aquatic living beings (JC2, n = 2; 11.8%), changing habitats and impact on living beings (JC3, n = 4; 23.4%), disturbance of two of Earth’s subsystems (JC5, n = 2; 11.8%), and impact on four of Earth’s subsystems (JC6, n = 2; 11.8%). One participant made the following statement:

[P7] “Despite the need for minerals to develop even more renewable energies, mining will increase the turbidity of the water because of the sediment plume formed, which might impact the photosynthetic beings, thus affecting the atmosphere. Mining also directly impacts the biosphere because it can cause the death of animals and habitat destruction; the geosphere because it promotes the decrease in the reservoirs of the polymetallic nodules; and the hydrosphere due, for example, to the impact of the pollution caused by the ships that transport the collectors”.

A detailed analysis of Table 4 reveals differences in the complexity of justifications provided by participants before and after the intervention, regardless of whether the impacts were perceived as positive or negative. To facilitate this analysis, the codes were grouped based on the number of impacts mentioned as follows: (i) Group I includes justifications with none or only one impact of DSM (codes JA, JB1, JB2, JC1, and JC2), and (ii) Group II includes justifications referencing two or more impacts of DSM (codes JB3, JC3, JC5, and JC6). In the pre-test, most participants (n = 15; 88.2%) provided responses within Group 1. This number decreased significantly in the post-test (n = 6; 35.3%), reflecting a reduction of 52.9 percentage points. Conversely, the proportion of responses in Group 2 rose, with only one participant (1; 5.9%) in the pre-test compared to 11 participants (n = 11; 64.7%) in the post-test, reflecting an increase of 58.8 percentage points. The following observation was made by one participant:

[P8] “The water becomes cloudier because of the rise of sediments in the sea floor, and this will have an impact on the animals that live there…some might die because they cannot find food, and others might try to move to other areas in order to find it, changing the biodiversity of that habitat. Yes, we need metals for increasing green energies, but we cannot do so at the expense of harming an ecosystem as vital as the ocean”.

4. Discussion

This study demonstrated significant shifts in participants’ understanding and attitudes towards DSM following the educational intervention. The intervention successfully addressed initial gaps in knowledge, equipping them with the information needed to form a clear position about the issue, as evidenced by the reduction in “I don’t know” responses in the post-test. This finding aligns with educational research emphasising the importance of targeted interventions in enhancing students’ confidence and competence in making informed decisions regarding complex SSI, such as some environmental problems [77,78,79], thereby enhancing scientific literacy [80].

A key outcome was the increased complexity of justifications, with post-test responses incorporating broader considerations, such as the interconnected impacts of DSM on Earth’s subsystems (e.g., hydrosphere, biosphere, geosphere, and atmosphere). Participants’ insights into DSM impacts, such as sediment plume formation, increased water turbidity, and marine life threats, including direct mortality, lack of food or loss of habitat, match well-documented environmental concerns in the literature [1,32,33,40]. For instance, students linked sediment plumes to reduced photosynthesis and habitat degradation, echoing findings on DSM activities’ broader ecosystem effects [13]. Although participants did not mention specific disruptors like noise pollution or large-scale sediment dispersion, specialists highlighted these considerations as additional risks to biodiversity and ecosystem function [33]. Findings are consistent with the literature that argues that role-play activities encourage students to engage with multiple dimensions of SSIs, thereby enhancing their ability to analyse evidence from different perspectives and elaborate improved arguments [22,81,82]. A recent study [83] recommended employing role-playing game-based approaches as part of an integrated marine sustainability education to equip students with the skills necessary for actively contributing to and supporting sustainable ocean development. Other authors [64,84,85] also indicate that modelling activities can effectively promote systems thinking by helping learners visualise relationships within complex systems.

This investigation suggests that combining role-play and modelling yielded positive indicators regarding developing systems thinking, argumentation, and decision-making skills about DSM, thereby improving participants’ scientific literacy on the topic. Moreover, the skills developed are important for maintaining actions aligned with planetary sustainability [29,86]. The shift in participants’ stances on the topic aligns with the views of many experts in the field who, while acknowledging the necessity of the green energy transition and the associated demand for critical minerals, consider that there is still a very limited understanding of the risks that DSM poses to the ocean’s ecosystem future and therefore advocate for a precautionary approach to deep-sea mining [1,17,33,34,40,41,42]. This precautionary approach advocates postponing DSM activities until there is sufficient evidence to ensure that ecological risks can be minimised. This principle underpins the ethical considerations raised during this intervention.

The ISA’s ongoing struggle to adopt a definitive position and finalise the mining code exemplifies the complexities of addressing global resource management amidst environmental uncertainties. This reality highlights the critical need for Earth system literacy, as many authors acknowledge [68,69,70,87].

The results are particularly interesting, given that the participants came from disadvantaged socio-economic backgrounds. According to several authors, this fact negatively impacts learning outcomes [88,89,90]. These findings are significant as they suggest that non-formal educational settings have the potential to bridge learning gaps by effectively fostering scientific literacy and critical competencies. Such settings may succeed when traditional formal education often falls short, providing accessible and impactful learning opportunities for socioeconomically disadvantaged groups. Additionally, this work could be a foundation for developing further educational resources leveraging these strategies in other challenging and complex topics. For instance, combined role-play and modelling activities could be adapted to explore other issues like ocean acidification and marine ecosystems, sustainable urban development, habitat degradation and biodiversity loss, food security and sustainable agriculture, and infectious diseases and public health. By engaging learners in these critical topics, similar approaches could promote systems thinking and informed decision-making, further demonstrating the value of non-formal education in addressing global sustainability challenges, as acknowledged by Wals and collaborators [54].

This study faced some limitations concerning its small sample size, which does not allow the findings to be generalised. Participant diversity in age and grade levels could also have influenced learning outcomes. Future research should involve larger, more homogeneous samples to better isolate the intervention’s impact. Furthermore, testing the approach in formal educational settings alongside non-formal contexts could offer valuable insights into its broader applicability and scalability.

5. Conclusions

Finding a balance between the benefits of natural resource use and the associated environmental costs—such as damage to the Earth’s critical ecosystems—remains a major challenge for both science and society. This study demonstrated the effectiveness of integrating role-play and modelling activities into non-formal education in deep-sea mining. Despite its small sample size, the results indicate that the participants improved their scientific literacy, systems thinking, and decision-making skills. The intervention addressed the growing need for educational approaches that go beyond traditional content delivery, emphasising students’ engagement with a real-world problem. By equipping learners with the skills to tackle global challenges, such as climate change and resource depletion, this approach fostered a deeper understanding of the environmental, social, and ethical dimensions of deep-sea mining. Ultimately, it prepared participants to make more informed and thoughtful decisions about our planet’s future.