Abstract
Education for Sustainable Development (ESD) is an educational imperative that requires supporting young learners in developing awareness about–and exploring–concepts, topics and vocabulary of significant importance in environmental education. Chawla (2009, Journal of Developmental Processes, 4(1), pp. 6–23) identified two factors that predicted pro-environment behaviours: (a) direct experience in nature and (b) second-hand learning such as through books and stories. By using carefully selected children’s books that affirm and underscore children’s relationships with nature, classroom teachers and programme leaders can support inquiry-based learning in a recurring and interrelated fashion. Additionally, a wide range of constructs and content embedded within the realm of environmental education can be explored through carefully selected children’s reading materials.
Keywords
Education for Sustainable Development (ESD) is an educational imperative of international importance. Coordinated by UNESCO, the imperative is a call to ‘constructively and creatively address present and future global challenges and create more sustainable and resilient societies’ (UNESCO, 2016). In early childhood education, the imperative can be broadly framed in many ways, including the necessity of exploring and deciphering ‘pedagogy, place, participation (of children) and…paradigm shifts towards more socially just and democratic education’ (Tilbury, 2014, p. xv), and situating and involving children ‘as thinkers, problem-solvers and agents of change for sustainability’ (Davis & Elliott, 2014, p. 1). The United Nations Convention on the Rights of the Child asserted that children’s basic rights include access to environmental education and a voice in decisions that impact their lives (UNICEF, 1989). It is imperative that teachers and other adults recognize children’s right to understand and reflect on their place in the environment and support their development of understanding of issues related to the environment. (See Figure 1 for an illustration of a children’s curriculum model incorporating these features [CAPI Curriculum Model]).

The Early Childhood Years
The experiences of childhood are significant formative influences, impacting children’s emotions and affection for the world around them and, concurrently, affecting their development of knowledge, skills and dispositions. While each child’s contextual influences are obviously different, the early experiences nevertheless form the critical foundations that later successes depend on. ESD in early childhood, or Early Childhood Education for Sustainability (ECEfS) 1 as referred to by Davis and Elliott (2014), are necessarily further guided by the virtue of the ‘young ages’ of children. As a result, Wilson (cited in Early Childhood Environmental Education Programs: Guidelines for Excellence (NAAEE, 2016)), frames—and implies—that early childhood curriculum in general (and especially for programmes based on, or integrating, ECEfS) should encompass ‘the development of a sense of wonder; appreciation for the beauty and mystery of the natural world; opportunities to experience joy of closeness to nature; and respect for other creatures’ (p. 2). In other words, the ESD curriculum in early childhood, which can be integrated as part of existing programmes or adopted as the guiding principle affecting the entire programme, should be ‘an appropriate and positive process whereby educators can start young children on their journey towards becoming environmentally responsive youth and adults’ (NAAEE, 2016, p. 3). Figure 2 illustrates how these first-hand experiences and second-hand learning (such as reading or listening to storybooks) may be integrated within (or funnelled into) the broader ECEfS curriculum framework.

Developmental Considerations In The Teaching Process
Understanding age-related characteristics and how young children learn are important considerations in the preliminary design of the curriculum. The preliminary design should address appropriate psychological climates, social interactions, indoor and outdoor classroom arrangements, and material manipulation activities that most effectively respond to age groups and learning modes of young children. However, while it may be expected that children in specific age groups may demonstrate similar behaviours, knowledge and skills, it must also be recognized that developmental variation in individual children is an expectation. The influences on the individual variation are based on both constitutional (i.e., nature) and nurture (i.e., prior experiences received from social-cultural contexts) reasons. As a result, teachers and the teaching process must respond appropriately to each child’s differing learning needs as well. In the case of environmental education, awareness of developmentally appropriate practice (DAP), as described by Copple & Bredekamp (2009), is of paramount importance.
Age-related Characteristics
Toddlerhood
For toddlers, primary needs include security and exploration. Mobility provides opportunities for exploration and tactile stimulation related to one’s immediate surroundings. Exploration in natural settings helps very young children develop sensory awareness, and supports the development of a framework of understanding the natural and built environments. Concurrently, they are beginning to develop a sense of self in relation to others, which is made stronger through increased opportunities for interaction with others and exploration of the environment. Rapid growth in motor development brings opportunities to construct knowledge about one’s own range of motion, balance, centre of gravity and physical abilities within the context of the natural world. Physical challenges presented by natural elements such as stumps, variations in terrain and differing textures help the toddler to develop an awareness of the diversity of shapes, sizes and structures in the natural world, and how they related to his own being. Toddlers love books and stories, and are prone to imitating the ‘stories’ they see acted out in the behaviours of others (Copple & Bredekamp, 2009). They are innately curious about animals and other living things. For this reason, reading and sharing stories about animals and nature will be attractive, and toddlers relish the opportunity to look at pictures of animals, imitate animal noises, and ask questions about animals with a caring adult.
Preschoolers
The ages between 3 and 5 years are commonly referred to as ‘preschool years’ although many children do attend childcare programmes that very much resemble schools. Learning and development of a physical, social, cognitive and emotional nature happen during this time, and support and participation from a caring adult is crucial in children’s development. Chawla (2007) noted that frequently spending ‘time outdoors with a caring adult’, whether in free play or exploration of nature, was a significant factor in the development of many environmentally minded adults. Therefore, time outdoors in natural settings should be a high priority for caregivers and other adults who wish to support children’s sense of connection to nature. During this period of development, preschool aged children are also intensely interested in books, photographs and other media. Stories are captivating and help children create context and meaning, as well as prompt them to think about their own experiences in nature and other settings. When nature is portrayed in media, adults should be mindful that illustrations, descriptions and other representations are ethical, accurate and generally positive (e.g., as opposed to stylized portrayals of animals or depictions of animals as aggressive). In other words, nature should be portrayed as a welcoming, safe place. In many cases, children at this age are able to identify with animal characters more readily than with human characters (Burke & Copenhaver, 2004), and stories featuring animal characters can therefore be particularly comforting, soothing or arousing.
During this age, children are also internalizing their culture’s collective values and expectations (Thompson, 2006). ‘Morality’ is demonstrated often as is a sense of justice, as children experiment with what it means to be ‘right and wrong’ and explore the purpose of rules. This has important implications for ESD when one considers that adults who act on behalf of the environment often do so as a result of their values, their own morality, and their sense of right and wrong. Modelling pro-environment behaviour has a powerful effect on children in the preschool years.
Learning Through Play
Play is a central consideration and an important element in young children’s curriculum. When children engage in play, a variable number of interplays occur to advance the child’s knowledge, development of skills and development of dispositions. Play is an important mechanism–be it through pretend or symbolic play, discovery learning, constructive play or socio-dramatic play—tied to practice and internal motivations that assist the child in achieving greater abilities and maturity over time. Children are actively engaged in learning processes during playful and enjoyable activities. Incorporating opportunities to learn through enjoyable experiences and play is an essential method of teaching. Play in nature is of particular value in relation to ESD, since nature-based play helps to develop children’s attention to qualities and conditions in their local communities (both built and natural) as well as helping to strengthen their social connection and development in relation to others, which suggests that children are inclined to take positive action by virtue of the time spent in nature. Unstructured, child-directed nature play affirms children’s sense of nature as intrinsically valuable and meaningful (Kellert & Wilson, 1993), which may later evolve into a deeper connection with the natural world.
Scaffolding
Scaffolding refers to the many ways that more experienced individuals such as older siblings, parents and teachers can provide appropriate and needed aid during children’s learning processes (e.g., learning to say new words, demonstrate behaviours or practise skills). According to Vygotsky (1930–1934/1978), scaffolding is most effective when (a) the help provided is appropriate and just challenging enough for the child, (b) the help provided is relevant to the learning experience, and (c) the new skills expected of the child is within the child’s developmental and educational reach. Related to scaffolding is the concept of zone of proximal development (Vygotsky, 1930–1934/1978), which refers to a child’s ‘learning’ zone that is (a) just above the current abilities of the child and (b) just below the knowledge or skills that the child cannot attain even with the aid of a more experienced individual. In other words, scaffolding pre-supposes the zone of proximal development to be appropriate learning experiences that a child can master given an experienced individual’s assistance.
As with language development, children’s nature experiences can be scaffolded. Adults should aim to build and support children’s comfort and stimulate curiosity in alignment with the needs presented with each developmental stage. In doing so, adults can help to create a solid base of security in nature, followed by lots of opportunities to explore and investigate one’s surroundings. By doing so, children are afforded opportunities to create that sense of familiarity with the place and community that is important in the development of a conservation or sustainability frame (Lieberman & Hoody, 1998; Sobel, 1996, 2007).
Adults can scaffold nature experiences with an eye towards the development of a strong conservation mindset or connection to nature. Scaffolded nature experiences respond to children’s developmental needs and support them in developing further. For example, in the early years, adults should concern themselves with providing opportunities that support a child’s sense of security and belonging, such as plenty of time for reading or relaxing and playing outdoors, going for walks, and being connected and close to caregivers through shared experiences in nature. When children reach preschool age, adults should seek to provide experiences which allow for healthy and age-appropriate risk, investigation of lots of phenomena and hands-on experience with a variety of natural materials. These experiences may be described as being ‘scaffolded’ as they respond to developmental levels and change. As children age, Sobel (2004) writes that in order for children’s ethic of care to extend to the global ecosystem, they should be supported in caring for and connecting to the natural environment, in age-appropriate ways, supported by adults who help to shape the school environments that model environmental sustainability.
In early childhood, children are learning about and developing their sense of agency (e.g., ‘what can I do?’). Experiences that support the development of agency are experiences that let children try new things, take risks and experience the effects of their own actions. They see that their behaviours have a positive (or negative) impact on their environments and relationships with other living things, and they internalize that knowledge to develop a sense of control. Sobel (2007) and Chawla and Derr (2012) argue that it is this sense of control and agency that later lead children to a sense of responsibility that leads to a desire to make informed choices that have a positive effect, which is the essence of sustainability.
Intentional Teaching
Intentionality ‘is the hallmark of developmentally appropriate teaching’ (NAEYC, 2009). When teachers are being intentional, they are cognizant of each child’s learning needs (in both developmental and educational terms), and are purposeful in the design of indoor and outdoor classroom environments, delivery of instruction, interactions and responses, and assessment strategies over time. In other words, intentional teachers direct their efforts in helping children attain new knowledge and skills in a recurring and interrelated fashion as the children mature over time.
Being intentional with regard to nature-based settings involves teachers directing their efforts to ensure that the materials and settings are appropriate for the child’s age and developmental level as well as supporting children in their nature exploration in ways that honour their developmental stages and allow children to experience nature directly. It also means selecting books, media and other materials for ‘indirect experiences with nature’ with a recognition of the importance of accurate, respectful and sensitive portrayals of the natural environment as well as the non-human animals presented.
Finally, being intentional means knowing when and how to introduce environmental topics without introducing too much responsibility or culpability on the shoulders of young children. Doing this requires an understanding of children’s development in relationship to conservation-mindedness (Chawla & Derr, 2012; Sobel, 2007).
Issues Affecting Children’S Development And Education
‘We have met the enemy and he is us’. 2 This statement aptly describes the conundrum related to the social and cultural assaults on young children today. The enemy is ‘us’ and comprises of the significant complexities associated with a burgeoning global population, consequences on urbanization and its effects thereof, wealth accumulation and its associations with screen watching and health issues, commercials and corporate marketing of products and its impact on children’s consciousness and motivations, and lack of due diligence and needed initiatives by many stakeholders despite the risks to humanity in general and children in particular. UNESCO’s call for ESD is a clarion call to address the creation of ‘more sustainable and resilient societies’ starting in early childhood, where appropriate consciousness about sustainability can be nurtured and where appropriate experiences nurture children to become ‘thinkers, problem-solvers and agents of change for sustainability’. The call also means confronting and addressing the aforementioned assaults through appropriate experiences in children’s lives.
All too often in early childhood education, well-intentioned educators who wish to instil a sense of environmental responsibility and stewardship, bring up ‘too much, too soon’, presenting children with environmental facts and information that are well beyond children’s ability to handle emotionally (Sobel, 2007). This may come in the form of videos, fiction or non-fiction stories, and other media or even simple games or other activities with inappropriate themes such as extinction, overpopulation and deforestation. With this practice comes the risk of creating a sense of alienation, anxiety, guilt or fear, all of which can result in a child feeling so hopeless about the future that they disengage.
Curriculum Themes
Based on the perspectives related to ‘appropriate and positive process’ and concerns expressed in the prior section, the ECEfS curriculum model can now be further refined to include several pertinent themes or topics of study. Curriculum themes may now be generated as being (a) appreciation for nature, (b) caring for nature, (c) leading healthy lifestyles and (d) practising sustainable living (see Figure 3 for an illustration of the variables informing curriculum themes). Within the discipline of environmental education, experiences often fall into one of three categories—those that are ‘in’ the environment, ‘about’ the environment or ‘for’ the environment (Davis, 1998, 2009; Deans & Brown, 2008; Lee, 2001; Lee & Ma, 2006). In other words, these themes are integrated within the curriculum goals of place-based learning, in-depth studies and children as change agents.

In addition to developmental considerations in the design of psychological and physical learning climates, these themes suggest significant implications for the needed experiences and interactions in the overall curriculum. Figure 4 highlights four themes that can serve as topics for in-depth and recurring study. Appreciation for nature addresses the development of awareness, enjoyment and wonder, and gratitude for the natural world. Caring for the natural world, on the other hand, refers to the actions and respect that the natural world requires to maintain healthy ecosystems for the mutual benefit of all. Both appreciation and caring for the natural world arise from frequent, extended opportunities for play in nature. Leading healthy lifestyles concerns the development of healthy eating and physical activity habits, which also counters health issues related to processed foods, screen watching, passive activity and other health risks. Certainly, these choices and their underlying values are those that can be effectively modelled by adults. Practising sustainable living focuses on knowledge and skill building related to gardening, reducing waste, reducing use of chemicals and toxic pollutants, and other activities that favour the conservation and restoration of the natural world.

Place-based Education
Place-based education directly engages children’s use of their senses in real settings (as opposed to learning in classroom settings, or obtaining information through books and other media sources). Place-based education takes place in real settings and offers the most direct contact and experiences pertinent to the curriculum goals and topics of study. In early childhood, this generally means that learning takes place outside of the class and extends into the surrounding places and communities (Lieberman & Hoody, 1998). In ECEfS in particular, this means that children have regular opportunities for interacting with the natural outdoors to meet the common goals and engage in in-depth study related to the curriculum themes identified earlier. As noted by Sobel (2004), children develop a sense of belonging and responsibility towards local environments and communities through immersion and direct experience. Hart (1997) noted that children need opportunities to learn in their local communities, where issues are visible and tangible, in order to best see the effects of their own actions and develop a sense of efficacy. Community in this context can refer to a child’s neighbourhood, schoolyard or backyard. Here, a child can take an action that will have an impact that is tangible and evident to the child.
Project Approach
Projects are in-depth investigations of interest to children. Projects may be undertaken by individual children, small groups of children or an entire classroom of children. ‘Projects provide contexts in which children’s curiosity can be expressed purposefully, and that enable them to experience the joy of self-motivated learning’ (Helm & Katz, 2016, p. 3). Engagement in projects also appears ‘to strengthen young children’s motivation to master a wide variety of skills, including reading and writing’ (Helm & Katz, 2016, p. 8). In contrast to traditional classroom teaching approaches where learning is decontextualized and structured, projects nurture understanding and the application of the understanding in more motivating and meaningful ways. Consisting of three phases, the project approach first engages children in posing questions related to topics of interest. The teacher may also integrate relevant educational standards and other mandated or necessary experiences at this initial stage. In the middle phase, children are guided in conducting ‘investigations,’ seeking answers and checking on initial predictions. Children may be encouraged to express their findings (i.e., learning) in many ways appropriate for the age levels. In the final phase, children plan an event to share their projects. The events can occur in many forms and the audience can range from any number of social groups, including families. Within the context of nature, projects often help children develop a deeper awareness of systems and processes as they often span greater periods of time and involve many connected and related elements.
Knowledge Structure Development
Throughout the ECEfS approach, children will naturally demonstrate their growing environmental literacy. Vitale (2014) identified 11 types of knowledge that children can learn and use to demonstrate ‘what they know’ (see Figure 5). These knowledge types can easily be incorporated in the ECEfS curriculum through appropriate teacher modelling and scaffolding, and be followed by the children themselves using the knowledge in everyday conversations and experiences. Over time, and with continued scaffolding, children can be expected to achieve greater fluency in their level of environmental literacy pertinent to the previously articulated common curriculum goals.

Content Learning
Content learning in environmental education, or learning ‘about’ the environment, overlaps significantly with content learning in science as well as other disciplines including language arts, mathematics and social studies. According to Worth (2010), content learning in science should focus on both life and physical sciences. Earth science is a natural opportunity as well when intentional teaching supports the development of content knowledge through hands-on investigation. Scientific inquiry and content learning in early childhood, however, is qualitatively different (i.e., learning is not an explicit process) and must be developmentally appropriate (Worth, 2010). Involving place-based education and knowledge structure development identified earlier, an appropriate model for content learning in the early childhood curriculum centres on (a) direct exploration of materials and phenomena, (b) awareness and use of scientific processes, (c) in-depth investigations over time and (d) sharing of multiple perspectives. Figure 6 illustrates a scientific inquiry model appropriate for young children (Worth, 2010). Obviously, the scaffolding provided by teachers (e.g., encouraging children to notice, wonder and explore) as well as the intentionality in the teachers’ inquiry approaches (e.g., modelling thinking or investigation processes) is an important aspect imbedded in this model. The teacher must be informed by both the characteristics of children and the appropriate science knowledge and pedagogic skills.

Children’s Books as Sources of Information
Children’s picture books represent an essential resource in the teaching and learning process for young children. Selected carefully, the books serve as a source of knowledge for supporting both the curriculum themes and content knowledge in the life and physical sciences. In other words, appropriate children’s picture books can serve as sources of inquiry, content information and guides in conscious thought development. Table 1 provides examples of children’s books related to the curriculum themes while embedding constructs and content information appropriate for young children.
Examples of Children’s Picture Books Related to ECEfS Curriculum Themes
Book Selection Process
In evaluating children’s books with an eye towards ECEfS, the following recommendations, or consideration of these details, will ensure that teachers and other care- givers best support children’s developing knowledge about nature, their connection to nature and their appreciation for nature through literacy experiences:
Choose books that approach environmental topics with sensitivity and grace. It is far better to choose those books that inspire wonder and curiosity than despair and fear. Some children’s books dealing with environmental issues rely on fear and despair. This may be overt or it may be subtle. Read a book several times yourself, and consider the message. Is it one of fear, shame or punishment, where humans are portrayed as creating problems for other living things or as the ‘bad guys’? Look carefully at the roles or responsibilities of children encouraged in the stories. In one popular story, children are urged to recycle or else face the consequence of a world being overtaken by garbage, which may not be appropriate depending on the maturity of the child or children. How is nature portrayed? In many children’s books, especially those published in more recent years, nature is presented as being dismal or bleak. It may appear barren or it may not appear at all. Avoid these books, as they will perpetuate a disconnect from the natural world and add to the children’s feelings of hopelessness. Be aware of how animals are portrayed. Avoid books that villainize or portray certain species as aggressive, unintelligent, or malicious. It is better to avoid anthropomorphism altogether. Children are very sensitive to the way animals and other main characters are portrayed. Make multiple copies of books available. Make time for children to page through the books on their own, making observations and asking questions about what they see. Listen to their observations and questions, and engage in thoughtful discussions about it.
Development of Literacy Skills
Successes in early literacy development are associated with greater academic and economic achievements later in life. As children mature, it can be expected that young children will proceed from being non-readers to more fluent readers over time. In early childhood, literacy curriculum should focus on children’s development in three key areas: oral language, alphabetic code, and print knowledge and use (Strickland & Riley-Ayers, n.d.). Along with their reading abilities, their comprehension of the text or material read too should enhance over time, given appropriate nurturance and opportunities. Table 2 summarizes developmental expectations of young children’s literacy skills from toddlerhood to elementary ages. In toddlerhood, for example, it can be generally expected that children will enjoy listening to stories, will hold and pretend to read books, may comment on the pictures seen or recognize books by their covers. The implications for teaching during toddlerhood, as a result, can be (a) making appropriate books available inside and outside of the classroom, (b) reading books appropriate for the attention span, and (c) asking and commenting about book covers and pictures. For late preschoolers and kindergarteners, for example, the implications may include asking questions about the stories read and encouraging children to read books aloud by themselves. Of course, the content being read (by either the child or teacher) must be appropriate and more challenging over time.
Development of Literacy
Conclusion
This article suggested a multilayered curriculum model called CAPI (Children as Agents in Place-based Investigations) as a means of addressing the pedagogical concepts and learning processes of importance in ECEfS. Direct experiences in natural environments were described as the primary learning contexts in achieving the curriculum goals of children’s joy of closeness to nature, sense of wonder and appreciation for the beauty and mystery of the natural world, and environmental literacy development. Complementing direct experiences in nature, reading materials were emphasized as an essential aspect of the curriculum model. Children’s reading resources that focused on appreciation for nature, caring for nature, leading healthy lifestyles and practising sustainable living provided indispensable informational and learning opportunities surrounding the curriculum goals. By providing first-hand experiences and appropriate scaffolding in the development of children’s own sense of agency most related to environmental sustainability, children are supported in their development of knowledge, skills and dispositions as well as in their voices and inquiries throughout the learning process.
Declaration of Conflicting Interests
The authors declared no potential conflicts of interest with respect to the research, authorship and/or publication of this article.
Funding
The authors received no financial support for the research, authorship and/or publication of this article.
