“Human beings, in addition to being part of nature, also depend on it”. This idea, taken from the book Man and Nature by George Perkin Marsh, published in 1864, demonstrates the undeniable need for environmental care [1]. However, the environmental crisis we are currently experiencing is undeniable. In recent decades, numerous reports have highlighted the increasing danger of environmental deterioration, which means that crucial global challenges must be overcome for humans to coexist with quality guarantees [2]. The significance of these climate issues even affects society at large, for example, evidence has been found that the effects associated with global warming are causing more and more people to leave their homes in search of safety and a better quality of life [3]. It is for this reason that all social sectors should respect, promote, and take into account their specific human rights obligations when adopting the necessary measures to combat climate change [4]. However, bold, specific, and immediate actions and greater ambition from all parties are required, especially from those who can lead by example [4].

Previously, from the 55th session of the United Nations General Assembly held in September 2000, emphasis was placed on not sparing any effort to combat socioeconomic and environmental problems, which affect more than a billion people. As a result, the United Nations established the eight Millennium Development Goals (MDGs) [5], specifying concrete targets to achieve by 2015 [6]. The objectives of this global initiative include: eradicating poverty and hunger, universal primary education, gender equality, reducing child mortality, improving maternal health, combating HIV/AIDS, malaria, and other diseases, ensuring environmental sustainability, and fostering cooperative work toward development [5]. As seen in these MDGs, for UNESCO, education remains one of its priorities, as it is an essential human right for consolidating peace and promoting sustainable development. This is why we currently refer to the 2030 Agenda for Sustainable Development adopted by the United Nations General Assembly on 25 September 2015 [7]. The 2030 Agenda presents 17 Sustainable Development Goals (SDGs) broken down into 169 targets [6]. These goals are universal, transformative, and inclusive, and they highlight the main challenges facing humanity for its development, that is, global challenges for human survival. But to achieve the SDGs and create a more sustainable planet, people need to become change agents [2]. In other words, they require learning, skills, values, and attitudes that drive them to contribute to this change. Therefore, this tool must be used in education, as it is crucial for achieving the SDGs. This global framework for action has, among its priorities, the goal of redirecting the joint actions of humanity towards sustainability. The 2030 Agenda outlines the most pressing challenges of our time, including poverty, inequality, climate change, and environmental degradation. These goals are divided into three interdependent dimensions: economic, social, and environmental. Examples of the economic dimension include goals such as promoting sustainable and inclusive economic growth (SDG 8) and reducing poverty (SDG 1). The social dimension includes goals such as improving social equity (SDG 10) and ensuring quality education (SDG 4). The environmental dimension includes goals such as protecting the environment and combating climate change (SDG 13) and ensuring sustainable management of terrestrial ecosystems (SDG 15). Given the breadth of these goals, a guide is presented to help with the steps to be taken in promoting their specific contribution through education. This is implemented because education has great potential to challenge and transform relationships, changing social norms and practices considered unequal and necessary, to encourage people to accept current needs and challenges as a fundamental priority and to safeguard our rights and the environment for a better quality of life [8]. Through these arguments, the role of education as a key and crucial agent for achieving the SDGs has been defended.

In this context, the importance of the education system has been highlighted, which must seek ways to improve students’ global awareness in order to train “environmental citizens” [9]. According to Finger et al. [10], this term is understood as those individuals who possess the knowledge, skills, values, attitudes, and competencies that allow them to be part of society while at the same time being agents of change at different scales. This should also involve the ability to act individually and collectively to provide solutions to current environmental problems. These competencies are in line with the recommendations adopted by the Council of the European Union in May 2018 on key competences for lifelong learning, which identifies eight fundamental skills. These competences, equivalent to those in the Spanish curriculum, are essential for personal development, promoting a healthy and sustainable lifestyle, employability, active citizenship, and achieving social inclusion [11]. In this regard and emphasizing the essential role of education in improving climate change, the Incheon Declaration was approved in 2015 at the World Education Forum [12]. This declaration demonstrated the need for a commitment from the educational community towards education and sustainable development, recognizing that education plays an essential role as a promoter of sustainability [12]. In this regard, we find the term ‘education for sustainable development’ (ESD), adopted by UNESCO, whose approach is for students to be able to make conscious decisions and act responsibly for environmental protection, a viable economy, and a fair society for present and future generations. It also states that ESD “aims to provide every person with the opportunity to acquire the values, competencies, knowledge, and skills that will enable them to contribute to a fair, economically viable, and ecologically sustainable human future” [13]. The Global Action Programme on ESD is currently in place, for which UNESCO [2] is carrying out its follow-up. Previously, on 20 December 2002, through the approval of resolution 57/254, the Decade of Education for Sustainable Development (2005–2014) was proclaimed, stating that “education is an indispensable element for achieving sustainable development” [14]. In this regard, according to Muguerza and Chalmeta [15], education has a dual role in achieving the SDGs: it is both a goal to be achieved and the means through which to achieve the remaining 16 goals. Following the same direction, Tilbury and Wortman (2004) indicate that education is fundamental to promoting sustainable development. This call for education for sustainable development (ESD) is echoed by various other organizations. The World Health Organization (WHO) explicitly associates physical activity (PA) with Agenda 2030 and thirteen of the Sustainable Development Goals (SDGs) in the Global Action Plan on Physical Activity 2018–2030 [16]. Due to these arguments, educational systems must correspond when defining the necessary learning objectives and content, introducing different pedagogies that give autonomy to students, as well as urging institutions to integrate sustainability principles into their management [2]. It has been observed that environmental education applied to children and adolescents ^[17][18][19][17,18,19] and university students positively influenced their environmental awareness; these results reinforce the importance of secondary schools for sustainable development [20]. This is why the need has been emphasized for teachers and those responsible for different subjects to reflect on the possibilities of contributing to the SDGs in their subject, apply them in the classroom effectively, and be trained to educate in sustainability [21]. However, it has been discovered that although 95% of teachers knew the importance of education on climate change and its effects, only a percentage lower than 40 had the confidence to teach it. One possible cause is that only 55% had received instruction on climate change [22]. In this regard, some subjects seem to show special potential to contribute to the SDGs, with physical education (PE) being one of the subjects that have shown the greatest trajectory to date. The documents “OECD Future of Education and Skills 2030: curriculum analysis” [23] and “OECD future of education 2030: Making physical education dynamic and inclusive for 2030 international curriculum analysis” [24] acknowledge that education, sports, and physical activity are essential for attaining numerous SDGs. Consequently, it is reasonable to assume that school physical education (PE) and physical education teachers (PETs) have the capacity to support these outlined visions. However, there is limited research on the specific methods and mechanisms for doing so [16].

There are different definitions of PA and, having universal popularity, everyone considers it a fundamental right. PA itself is empowering, motivating, and inspiring. Likewise, historically it has played a very important role in societies, thanks to its power to attract, mobilize, and promote peace, tolerance, and understanding beyond borders, cultures, and religions [25]. For Thorpe et al. [26], sports sociology scholars, compared to feminist social theorists such as Donna Haraway, have been slow to adopt environmental thinking, as they have emphasized centrally exploring nature and human relationships since the 1990s. Therefore, more concrete actions should be established in the different areas of study, starting from general education and specifying each action for each of the subjects in the secondary curriculum. However, a problem observed is the general lack of training for teachers [1] and, more specifically, for PETs [27]. The concern of teachers to try to connect environmental links with physical and health education is not new [28]. To assist in this task, it is necessary to specify the actions to be followed to achieve the SDGs. The World Congress of the International Association of Higher Schools of PE [29] already raised this need from an educational perspective. Few studies deal with the implementation of ESD from the school organization, but these have indicated four important aspects to achieve it: interact collaboratively and improve the school, focus education on students, cooperate with local society, and leadership [9]. In this sense, the connection between the characteristics of PE, such as motor development, promotion of justice, equity, diversity, and inclusion, etc., has been considered. To reduce these levels, sports practice is presented as a viable and sustainable solution, connecting sport, education, and society to promote sustainable behaviours in students [30]. The importance of the SDGs in the education system in general, and in PE in particular, and this has been reflected in new legislation. An example of this is the recent legislation proposed in Spain, which has been constructed and designed by establishing the 2030 Agenda and the SDGs as its backbone [31].

Education is a universal right, enshrined in the 1948 Universal Declaration of Human Rights in Article 26.1 [32] and also included in the Spanish Constitution of 1978 in Article 27. Because of this, Spanish educational policy has undergone changes over the years, highlighting a great expansion of the educational system, promotion of social equality, decentralization of the educational system, and the configuration of a new school model [33].

Educational laws and official curricula are the basic tools for teachers when developing their teaching work [34]. The way of understanding the curriculum has evolved over time, driven mainly by different factors, including the three dimensions of sustainable development: social, economic, and environmental [35]. In the social dimension, different laws have tried to adapt to new needs, taking into account different social groups ^[33][35][33,35]. The economic dimension has seen one of the most significant changes still affecting the curricula and, specifically, microeconomics, mainly due to the shift towards knowledge and technology-based growth ^[35][36][35,36]. Lastly, in the environmental dimension, focusing on climate change, EDS is promoted, and efforts are made to prepare students to become citizens with sustainable lifestyles [35]. These competencies must be taken into account when designing 21st-century curricula.

It is important to remember that many habits are acquired and consolidated during the school stage, both in primary and secondary education [37]. For this reason, the concept of sustainable development was introduced into educational curricula, due to the need for young people to be educated for a better future [38]. In 1968, environmental education appeared with the intention of promoting changes, one of its challenges being to seek personal and collective feelings of respecting the environment and using it without abusing it [39]. The following will be an analysis of the educational curriculum from the 1970s to the present day through the educational laws of Spain. With the General Education Law [40], the foundation was laid for the subsequent development of PE. Later, with the Organic Law on School Centres Statute [41], it is observed that for each course, there are five thematic blocks where there are contents of physical-sports activities in the natural environment (PANE) [34]. From 1990 to the present, there has been a legislative back-and-forth with up to six educational laws published: LOGSE [42], LOPEGCE [43], LOCE [44], LOE [45], LOMCE [46], and LOMLOE [47]. A large number of educational laws have been published in Spain in a short period, to the current point where students are being educated under the framework of two different educational laws and two curricular proposals [48].

Actually, the Spanish curricula is organized into five thematic blocks called basic knowledge, and also into five specific competencies that follow the achievement of the contents with their corresponding evaluation criteria. Additionally, eight key competences are also developed, which follow the competences outlined by the European Council. All these elements are developed for the first and second courses together, as well as for the third and fourth courses together.

The change to the LOE curriculum brought innovations in the content block of PE, with PANE appearing as its own block. Comparing LOGSE and LOE, we see that both have the same objectives: “To carry out physical-sports activities in the natural environment that have a low environmental impact, contributing to its conservation” [49].

The prior analysis of the curriculum shows us that in the LOE, an attitudinal content of respect for the environment and a positive valuation of its resources for recreational activities are added. In the third year, the contents are very similar between LOE and LOGSE. In the fourth year, LOGSE delves into orientation techniques, but LOE does not mention them, although in both curricula the aim is to understand the relationship between PA in nature and health, as well as their impact on the environment [49]. Regarding the evaluation criteria, in LOGSE there is only one related to PANE and it is about having respectful behaviour towards the environment and putting into practice the techniques for the development of activities. On the other hand, in LOE, the criteria are linked to the evaluation of the techniques indicated as contents of each course [49]. Both in the LOGSE and LOE curriculum, there is no specific block dealing with sustainable development. In contrast, LOMLOE is developed thanks to innovative aspects such as Agenda 2030 and the SDGs [31], in which there is also a specific block on sustainable development, block number 5, aimed at students integrating eco-socially responsible attitudes [50]. On the other hand, in LOMLOE, we find that the evaluation criteria are divided into five specific competencies, with those related to sustainable development being number five [50].

Delving into Royal Decree 217/2022 on 29 March, which establishes the organization and minimum teachings of compulsory secondary education, we see that the general changes are evident [31]. The objectives of PE in the LOMLOE stage are to ensure that students consolidate an active lifestyle, establish knowledge of their own corporality, enjoy cultural manifestations of motor nature, integrate eco-socially responsible attitudes, and reinforce the development of all decision-making processes involved in resolving motor situations. These contents contribute to being competent at the motor level, as well as facilitating comprehensive development, as it is an essential and inseparable element of student learning. After almost a decade of an inductive approach to competencies, it seems that the current LOMLOE has taken a 180° turn to make the leap to a real programming and evaluation by competencies [31]. The specific competencies of this subject become the reference to follow in shaping the PE that is intended to be developed: more competency-based, current, and aligned with the challenges of the 21st century. Similarly, they allow students to integrate an active and healthy lifestyle throughout their lives. To achieve this, six blocks of basic knowledge have been stipulated, which try to distance themselves from the old content blocks that conditioned the realization and development of particular didactic units, to avoid the interpretation and concretion of these in didactic units linked to a single block, as has been implemented to date, and thus be able to guide them towards learning situations [31]. In the case at hand, block 5, titled “Efficient and Sustainable Interaction with the Environment” [50] (p. 55), deals with the interaction of natural and urban environments in terms of their use, conservation, and shared nature. Focusing on specific competency number 5, it is observed that it is aimed at sustainable development, as it focuses, on the one hand, in secondary education on “Adopting a sustainable and eco-socially responsible lifestyle by applying individual and collective safety measures in physical-sports practice according to the environment and collaboratively and cooperatively developing community service actions related to physical activity and sports, to actively contribute to the conservation of natural and urban environments” [50] (p. 58). At this stage, students must consolidate environmentally respectful habits to contribute to global sustainability. Depending on the students’ level of maturity, from an ecological and social responsibility perspective, they will be able to participate in organizing activities in different contexts, whether natural or urban, respecting the environment and trying to improve it. Efforts at this stage will be aimed at consolidating a sustainable lifestyle committed to the conservation and improvement of the environment through activities to raise awareness, among others. They must participate in activities in natural and urban contexts to expand their motor skills and experiences outside the school context. In addition, from an ecological and social responsibility perspective, they will also design and organize activities that respect the environment, trying to improve and raise awareness about it. In general terms, it is understood that urban environments can include prepared settings for practicing PA: calisthenics circuits, roller skating, skateboarding, parkour, or urban dances. As for the natural environment, activities such as hiking, climbing, rappelling, skiing, maritime rescue, orientation (also in urban spaces), or bicycle touring can be practiced, all from a sustainable interaction approach, including complementary and extracurricular activities related to these experiences. This practice will also depend on the location of the school, its contextual possibilities, and the availability of access to different natural sites, both terrestrial and aquatic.