In this sense, it is important to identify the factors that facilitate the development of sustainability programs in the institutions and particularly, the alliances that can be achieved for their implementation, as well as the establishment of indicators that allow measuring their degree and level of compliance.
In the case of the Organization for Economic Cooperation and Development (OECD), an intergovernmental international organization made up of 37 states whose objective is to coordinate their economic and social policies, the phrase “green growth” was used in the declaration of the ministers of the Green Growth Group 21], as a factor for the incorporation of measures aimed at generating sustainability in the processes developed in the economies.
Therefore, the case of universities is analyzed, since they are the fundamental basis of academic processes, in which not only the transmission of knowledge should be conceived, but also the implementation of actions that generate economic, environmental, and social impact.
2. Sustainability in Universities
Universities must maintain constant contact with society, get involved in social issues, identify trends, and put knowledge into practice in order to achieve sustainability of human systems.
Tilbury [
31] states that higher education institutions are obliged to have a dynamic nature through which sustainable innovative processes can be established so that each of the curricula aims to be oriented to real life through relationships with different industries or other institutions.
According to Rieckmann [
32], the implementation of sustainability continues to be a great challenge for everyone, because competencies must be generated and must be developed by each of the academic programs and require methodological planning for effective learning in the student through educators and administrative staff, recognizing the importance of a common framework of different competencies that are constantly interrelated.
Thus, universities, which are institutions of higher education, are focused on training professionals in different areas of knowledge or work, through curricula, criteria, and comprehensive information; however, they have a great challenge in the face of sustainability [
33].
Unfortunately, the rare existence of training on the subject of sustainability for university teachers has been identified, and because of this, there is no real knowledge in the university community about the concepts of sustainability and curricular sustainability. Moreover, the institutional commitment is totally limited and has been difficult to integrate, bringing with it difficulties in putting into practice the theory that is taught in the classroom, trying to make learning didactic for contents, methodologies and evaluation systems [
34,
35].
In October 1990, in France, a meeting was held between 22 universities, with the aim of reaching an agreement to transfer the necessary bases for the generation of sustainable programs that would lead to solving problems related to pollution, unbalanced production and consumption trends, and poverty [
36]. From its results, the Talloires Declaration (1990) was born, which highlights the role of universities [
37] as the axis of education, policies, research, and implementation of activities that promote sustainability.
In this sense, universities have incorporated contents and competencies to be developed in their curricula, in order to generate academic programs highly oriented to sustainability [
38], without neglecting the generation of activities related to the changes that markets are permanently registering as a result of globalization.
In this way, elements are defined allowing to adapt the design of the curricula, and also the operational and institutional aspects of their activities [
39], which are based on quality, transparency in their processes, and the way in which they submit their reports [
40].
The measures they have begun to implement address issues focused on sustainability. According to Figueredo and Tsarenko [
40], this is supported by activities related to communication, considering that it is an influential process in all the actors that participate in the markets.
In 2010, the University of Indonesia established a Rankin of green universities to evaluate the responsibility and commitment of these institutions in relation to sustainability [
41] and has been working on this objective since 2006 [
42].
The process of sustainability in the university is not considered simple and involves a deep analysis of the educational model, with the aim of creating a strategy to make it more effective, and promoting changes based on the creation of culture as a model for sustainable development [
3].
This leads to encompassing substantive functions of higher education institutions, which generate leading professionals, from their profiles and tasks, in such a way that sustainability in future generations and contributions in the processes of building sustainable cities are important [
43,
44].
The mentioned commitments should support the involvement in the quality and importance of education for sustainability and the need to value aspects such as social, economic, and political aspects of sustainable development [
45]; it is also important to prioritize research, dissemination, partnership, campus operations [
46], programs and micro curricula, which allow introducing contents, methodologies, and practices that support teaching and training in competencies related to sustainability, which are specified in the profiles of future professionals.
Countries need sustainable universities for their economic and social development [
10]; it is necessary to generate processes of training, innovation, research, and problem-solving, which are based on the knowledge of the city, the academy is an engine for evolution, as a generator and executor of projects.
In view of the above, it is sought that future generations are integrated by responsible citizens and leaders, with priority in social awareness, in such a way that they perceive, witness, and meet the needs that arise, avoiding compromising the ability of future generations to meet their own needs [
11].
According to the United Nations Environment Programme (UNEP), a sustainable university is one whose activities are ecologically, socially and culturally equitable, and economically sustainable.
Two conceptual aspects are clearly highlighted regarding the role of the university in building sustainability. The first considers the issue of education as a fundamental practice for Higher Education Institutions to contribute to the qualification of their graduates and future decision makers so that they include the concern for sustainability in their professional practices. The second focuses on the positioning and behavior of these institutions in the implementation of sustainability in their university campuses. In other words, the vision of Education for Sustainable Development is broader and more comprehensive than that referring simply to theoretical discussion and awareness-raising based on data on sustainable development. Education for Sustainable Development encompasses both the theoretical side and the more practical action through policies, programs, processes, and operations on the university campus.
3. Sustainability of the Curriculum
In the coming decades, sustainability will become an imperative requirement for global society to address environmental challenges that can be seen in rising sea levels, increasing global temperatures, deforestation, loss of biodiversity, and decreasing availability of natural resources. If certain approximate threshold levels are exceeded, such environmental changes would cause serious disruptions to ecosystems, society, and economies. Because, to a large extent, these changes are the result of human consumption, moving toward sustainability would likely require radical changes in the values, educational systems, and social behavior that underpin current economic paradigms, consumption patterns, and power relations [
11].
Academic sustainability is collaterally related in the university curriculum to the environment, ethical behavior, poverty alleviation, gender equality, health promotion, human rights, cultural diversity, peace, responsible production, and consumption.
Universities are increasingly committed to the transmission of knowledge related to citizenship [
47,
48], which is considered the legal status that recognizes individuals as members of an egalitarian political community and is constituted by four dimensions: rights, duties or obligations, participation in the public sphere and belonging to a State—Nation [
49].
The concept of Education for Sustainable Development (ESD) has evolved to respond to the need for intervention in order to stop the deterioration of the natural environment and, as a consequence, to stop the impact generated by anthropic activity in recent decades [
50].
Linked to the analysis of the concept itself, this has been shaped in the way and the moment of incorporating it in the formative process of people. Indeed, a fundamental problem of higher education in the present century is to train students in the development of competencies for sustainability that will enable them to prevent and solve socio-environmental problems, as well as to carry out actions based on sustainable criteria in their future professional field [
50].
Therefore, there is no doubt that they must be able to:
-
Understand how professional activity relates to society and the environment at the local and global level, in order to identify challenges, risks, and possible impacts.
-
Generate spaces for discussion, design, definition, implementation, and evaluation of policies and actions in the public and private spheres, in such a way as to redirect society towards more sustainable development.
-
Develop a professional intellect based on deontological principles and universal ethical values, which protect human rights and the socio-environmental quality of their environment.
Universities, as institutions that train future citizens and professional leaders of society, have a decisive factor in the introduction of sustainability in the curriculum of students, called curricular sustainability (CS).
The goal from CS implemented by universities or institutions of higher education in intra- and extra-curricular areas is to make correct use of natural spaces and to understand that it is a source of resources but that we should not abuse what it has to offer, furthermore, the environment and its care is totally cultural and should be taught from childhood by our home tutors, understanding that the positive environmental values should be taught and that the interests of a few should not be a priority over the general welfare in ecological matters, so we must begin to promote work from the real possibilities to be effective in improving our actions [
51,
52].
The idea of educating for sustainability is to have a new vision of the world, to be able to think, feel and act to enter into the ecological, economic, and social dimensions, to reach those fundamental skills to achieve a new ethic that guides people’s ability to act in solidarity and equity, understanding that we are not the only living beings in the world [
53]. Different holistic and systemic approaches need to be connected to generate a policy of working together to make strategic changes in current pedagogy [
26].
The Conference of Rectors of Spanish Universities (CRUE), in the sectorial commission CRUE-Sustainability, is divided into a work team focused on curricular sustainability. The work of this group has produced results; in 2012, the document “CRUE Guidelines for the introduction of sustainability in the curriculum” was ratified. Spanish universities have different areas of research on how to incorporate sustainability in the university curriculum. One of the debates is whether to include it as a subject or as a transversal subject through competences [
53].
Building active and participatory citizenship is especially important during youth, when people become active protagonists of their citizenship status [
54], and educational institutions, such as universities, play an important role in this [
55,
56].
The construction of a citizenship committed to environmental sustainability, equitable economic development, and social and intergenerational justice makes education a key area to address the transformations that sustainability implies. This aspect has been present since the first international summits on this subject, such as the United Nations Conference on the Environment in Stockholm, 1972; United Nations Conference on Environment and Development in Rio de Janeiro, 1992 [
8].
The curriculum is considered one of the key elements that govern the educational process; it is where the learning necessary for the full development of each person takes shape, the idea is that through them adequate standards are achieved [
57]. It should be remembered that the hidden curriculum also exists when classes do not go according to plan and begin to cover different topics with active listening on the part of the students, which teaches them a specific topic that may or may not have been prepared beforehand.
In another vein, Smith and Dollase [
58] indicate that there are different pedagogical methodologies for teaching a wide range of skills that allow for the correct adaptation and creation of opportunities for concept learning, content, skills, and discoveries to be put into practice with the teacher playing the role of a coach who helps to change the focus of traditional exercises by instilling the new sustainable approach.
According to Lozano [
59] there has been an increase in the integration of sustainable development (SD) into the publication techniques of higher education institutions (HEIs). Several tools have been developed to assess SD in HEIs; however, only a few have focused on curriculum assessment. Curriculum assessment can provide an overview of how courses and programs incorporate SD.
The analyses showed that (a) teaching in European courses covers many sustainability issues in a fairly good balance, with the exception of social issues which are the least addressed; (b) there are correlations between economic, environmental, social, and cross-cutting issues; (c) women tend to teach SD in a more equal way than men; (d) types of HEIs do not influence the way SD is taught, but the educational level does; and (e) some countries, in the case of this research, Italy and Spain, may show more interest, although the average results tended to be lower than those of others, such as Sweden, the UK and the Netherlands. Curriculum assessment provides a diagnosis of SD incorporation and the factors affecting it.
This can help educators improve their courses and provide students with better SD knowledge and skills. Bautista-Cerro and Díaz [
60] found in an in-depth analysis of the reports of the UNED undergraduate courses a huge inequality in the presence and treatment of sustainability in each course, being relevant to the lack of citations referring to sustainability in the sections of competence and learning outcomes.
The main functions that these indicators should have are to diagnose sustainability, monitor our actions, evaluate university sustainability processes, communicate results, and raise awareness in the university community. To a large extent, this means that different indicators will be used for each of these functions and these indicators should be reflected in the Global University rankings that evaluate their performance.