An analysis of inclusion gaps in sustainable development themes: Findings from a review of recent social work literature

Recently, humans have negatively altered ecosystems more rapidly and extensively than in any other time in human history, contributing to gains in well-being and economic development for some, while threatening the security of most, particularly oppressed populations. We comprehensively reviewed recent social work literature (2010–2015) to examine gaps in environmental sustainability themes relevant to social work practice. Peer-reviewed manuscripts, dissertations/theses and white papers were examined. A total of 71 papers (less than 1% of social work literature) met inclusion criteria. Although our call is to protect human health and well-being, recent literature does not account for sustainability even with evidence that environmental issues directly impact clients, hindering practice efficacy.


Introduction
Humans have negatively altered global ecosystems more rapidly and more dramatically over the last 50 years than in any comparable time period (World Wildlife Fund (WWF), 2014. Humans cannot survive without a healthy planet. Earth's ecosystems and the services they provide allow for human life through the provision of clean air and water, food, medicines, disease management, building materials, fuel, climate regulation, storm buffering, security and shelter, spiritual fulfillment, and more. Yet, humanity's current natural resource consumption and carbon emissions combined exceed Earth's (land and sea) production and carbon absorption capacity by 50% (WWF, 2014), meaning Earth will be unable to sustain the burgeoning human population without intervention. These unsustainable demands have led to substantial gains in wellbeing and economic development for some, but at the cost of health, wellbeing, and security for most humans, particularly already marginalised and oppressed populations, making this a pressing social work concern. However, many social work professionals have not been exposed to the prevalence and severity of these environmental issues and the direct negative impacts on their clients, policies, and interventions. 2   2 Scientists have long known that excessively taxing Earth's natural resources and processes could lead to devastating consequences, including abrupt and irreparable environmental change (Meadows et al., 1972). In an effort to define parameters within which humans can develop sustainable societies, contemporary scientists have suggested nine planetary boundaries, or guidelines, for utilising each Earth system that minimises the risk of causing irreversible changes (Rockstrom et al., 2009;Steffen et al., 2015). These systems include climate change, biodiversity loss, nitrogen and phosphorus use, freshwater use, land use change, ocean acidification, stratospheric ozone depletion, atmospheric aerosol pollution, and chemical pollution; three boundaries that we have already violated are climate change, biodiversity loss, and nitrogen cycle disruption (Rockstrom et al., 2009;Steffen et al., 2015). Rather than strict tipping points that would flip a physical system into an alternate state, these boundaries are based on an evolving understanding of Earth's functioning and resilience; as such, they exist on a risk continuum where the farther these boundaries are transgressed, the higher the risk humans run of destabilising Earth's processes and eroding both human and Earth's resilience (Steffen et al., 2015). While Earth could rebound from such destabilisation, the resulting changes to Earth's environment would be so drastically different that human life likely could not (Steffen et al., 2015).

INCLUSION GAPS IN SUSTAINABLE DEVELOPMENT THEMES
Environmental changes are so pervasive and severe that scientists have suggested humans are already causing the Earth to exit the current geological epoch, the Holocene, which has existed for over 10,000 years and made the development of human civilisations possible, into the Anthropocene, a term under review by the International Commission on Stratigraphy to become a formal geological time period (Lewis and Maslin, 2015;Steffen et al., 2007;Steffen et al., 2011). The Anthropocene is defined as a period when human activity has overtaken vast parts of Earth's natural cycles, and in ways that threaten humanity's future (Lewis and Maslin, 2015).
The period 1800-1850 marks industrialisation's and the Anthropocene epoch's approximate onset, as industrial societies rapidly expanded their fossil fuel use (Steffen et al., 2007). Fossil fuels provided humans with abundant energy for developing new technologies (e.g., steam engines), eliminating previous energy supply constraints and altering and intensifying resource use for medicine and agriculture. Consequently, between 1800 and 2000, energy use grew approximately 40-fold, the global economy approximately 50-fold, and human population more than six-fold (Steffen et al., 2007). Since World War II, human population has continued to grow almost exponentially, doubling in 50 years, reaching more than 6 billion at the end of the 20 th century, and increasing to 7.6 billion as Population Prospects, 2017). Human activity has also rapidly increased, with the number of motor vehicles jumping from 40 million in 1945 to 700 million in 1996 and petroleum consumption growing 3.5 times since 1960 (Steffen et al., 2007). This alarming growth in population and consumption was occurring concurrently with early scientific recognition and documentation of the extent that human activities were affecting Earth's functioning (Steffen et al., 2007;Steffen et al., 2011).
Impacts of climate change, including rising temperatures, shifting seasons, sea-level rise, and increasing droughts and floods, threaten people's abilities to meet basic needs (Raworth, 2012). Already, 1,000 children die daily from climate change-related starvation and disease (Salomon, 2016). Furthermore, rising carbon dioxide levels contribute to the acceleration of environmental change and weather anomalies (Raworth, 2012).
Experiencing extreme weather events not only poses serious physical threats, but can also have severe psychological consequences by increasing individuals' overall stress, making increases in substance abuse, anxiety, depression, and suicide more likely (Clayton et al., 2014). Severe disasters like floods and storms can also have damaging effects on individuals, families, and communities by making people susceptible to post-traumatic stress disorder, significantly affecting children's learning and development, and even increasing physical aggression within the home (Clayton et al., 2014).
Excessive human consumption has depleted biodiversity levels below a safe threshold (Newbold et al., 2016), violating another planetary boundary and causing the 6 th mass extinction (Ceballos et al., 2015). Biodiversity loss has become so severeoccurring at a rate at least 114 times what is natural (Ceballos et al., 2015) that the current extinction rate is comparable to the last global mass-extinction event, commonly remembered as the dinosaurs' extinction (Sodhi and Ehrlich, 2010). Specifically, between In 2003, Mascia et al., put out a call to action to all social sciences to collaborate with natural sciences in conservation initiatives, for Earth and humanity's preservation. As a practice-based profession with adept skills in advocating for human health and well-being and organising and empowering communities, no social science profession is better poised to help protect a future for humanity than social work.

Methods
We performed a comprehensive review of recent social work literature (published 2010-2015) to uncover existing gaps in sustainable development themes relevant for social work practice. The review was completed according to a fixed and systematic plan The search terms were grouped into 10 categories: social work research AND sustainable development; social work research AND natural environment; social work research AND environmental sustainability; social work AND sustainable development; social work AND natural environment; social work AND environmental sustainability; green social work; environmental social work; conservation social work; and indigenous social work AND sustainable development. For each search yield, titles and highlighted search terms were first read to ascertain possible relevance. For pertinent titles and search terms and those that were published in a social work or social welfare journal, abstracts were read for appropriateness to our search. Most of the 1690 articles yielded were found to be irrelevant after abstract review; for example, "sustainable development" often meant sustainable development of an organisation (e.g., economically, human resources, ethically). Our criteria were that works needed to a) integrate human needs for the natural environment or needs for the natural environment's protection into social work research, or b) recognise the natural environment's importance to human health and development.
Works regarding nature's therapeutic benefits and/or of animals were not included as those were not germane to our concerns. However, if for example, a community organic garden INCLUSION GAPS IN SUSTAINABLE DEVELOPMENT THEMES 8 8 effort was conducted or evaluated by a social work or social welfare practitioner/researcher and found to also have mental health benefits to the community, those works were included. This same process was utilized for each separate database, and relevant articles were recorded in a research notebook by the first author and later reviewed by the second author. The first and second author conducted the review independently. To address interrater reliability, the second author's findings were compared to the first author's, which resulted in the inclusion of an additional 11 papers; the first and second authors reached aggregate consensus.
The general database search yielded 60 relevant publications. We further investigated the references cited in the original 60 papers for additional citations not covered in the database search. We elected to include this step out of concern that refereed journals requiring keyword selection from a pre-existing keyword database may not yet list of screened-in peer-reviewed manuscripts (including editorials), dissertations, theses, and white papers can be found in Appendix 1.
Study quality was not assessed, as that was not the review's intent. The objective was to analyse social work research to gain an understanding of if and how social work researchers were thinking about and/or addressing sustainable development. Study characterisation denoted eight categories: empirical, theoretical, pedagogical application, literature review, editorial/call to action, white paper, thesis, and dissertation.  Table 1 presents screened-in publication findings characterisation.

As
<Insert Table 1 here> Empirical studies most frequently used qualitative methodologies (n = 8 (44.5%)), followed by quantitative and community-based participatory action research methodologies that were equally represented with four (22.2%) articles each. Mixed-methods research was used in two (11.1%) articles. Only one product  included intervention research. Of the 18 theoretical articles published in peer-reviewed journals, six (33.3%) were specific to social work education. The three products classified as pedagogical application differed from these six articles, as they moved beyond conceptual modeling to present case studies evaluating specific teaching techniques or curriculum content previously used in a classroom setting.
We also analysed trends over the five-year period.

Discussion
Earth's continued sustainability for humans can no longer be taken for granted (Millennium Ecosystem Assessment, 2005;Rockstrom et al., 2009;Steffen et al., 2015).
Environmental changes due to unchecked human population growth and overconsumption now threaten human survival, with the poorest and most vulnerable on Earth impacted most significantly despite causing the least damage themselves (Raworth, 2012), making this a pressing social justice issue facing social work practitioners (Tedeschi et al., 2013).
While the review was limited by the inclusion of only English papers, findings led to the conclusion that recent social work research and academic literature do not adequately account for environmental degradation and sustainability issues, even when they are directly linked to human and social development. Despite evidence that many environmental problems are intrinsically linked with social justice issues aligned with social work's mission (e.g., food security, protecting environmentally induced migrants, or environmental racism) (Dominelli, 2012;, the lack of intervention studies in the review's findings indicate social work is failing to make a substantial contribution to mitigating environmental degradation's growing threat to human health, 12 well-being, and survival. The finding that environmental degradation and sustainability account for less than 1% of all social work research suggests that these issues and themes are not prioritised. If the products from the two special issues are removed from the data count, 36 peer-reviewed publications in a six-year time span remain. Publication biases, funding barriers, institutionally perpetuated disciplinary boundaries, and low value attributed to interdisciplinary research in tenure systems have been cited as impediments to interdisciplinary environmental research by both natural and social scientists (Roy et al., 2013), and have also likely hindered prioritisation of these themes in social work research and influenced these findings.
In a 2013 survey, 83% of 179 natural and social scientists conducting research at the human-environment interface reported frequent or occasional trouble publishing manuscripts since the interdisciplinary research did not adhere to preferred methodological and theoretical approaches or traditional journal guidelines, frameworks, and interests, which were often perceived as disciplinary (Roy et al., 2013). Though influenced by the presence of two special issues, the finding that more than 50% of screened-in peerreviewed articles were published in only four journals may be evidence of a publishing bias or challenge in regards to human-environment research rooted in social work. As such, the The documented schism between "evidence-based practice" and "practice-based research" in social work (Anastas, 2015) is also a reminder that the lack of environmental social work research may not be reflective of the extent that sustainable development and environmental degradation themes are incorporated into practice and unpublished or unevaluated interventions. Indeed, globally numerous social service organisations and grass roots organisations employing social work strategies are working at the interface of environmental challenges and social injustices and thus impacting both social and sustainable development (e.g., India's Navdanya, Kenya's Green Belt Movement, Cambodia's 3S Rivers Protection Network). While they may not disseminate their work through traditional academic (e.g., peer-reviewed literature) and development (e.g. white papers and technical reports) channels, these organisations present potential opportunities for collaborations with social work researchers who have the abilities to amplify these organisations' voices by assisting in the dissemination of their findings to newer and broader audiences.
Approximately 20% of all screened-in products, and 25% of peer-reviewed products specifically, are editorials or calls to action. While these articles often cite clear and cogent The enormity of problems and challenges often creates a paralysis or apathy that leads to inaction (Clayton et al., 2014;Moser, 2007), which in research and academia, is likely exacerbated by the aforementioned institutional barriers, publication biases, and other challenges to interdisciplinary research. This paralysis and apathy could be further complicated in social work, a profession that is already frequently overtaxed, and whose breadth of social injustices pertinent to its mission is continually expanding.
Regardless of root causes, these persistent gaps remain problematic. Without using research to explore the intricate links between environmental degradation and social justice, the social work profession will fail to build an evidence-base grounded in the profession's values or to inform practice with the marginalised and vulnerable communities social workers serve, who will be impacted most severely by environmental change. These literature gaps will also continue to perpetuate knowledge gaps in social work curricula and practice, creating a reliance on other disciplines to create the knowledge base that will be needed for future social work practitioners (Brekke, 2012). It can be said with certainty that INCLUSION GAPS IN SUSTAINABLE DEVELOPMENT THEMES   15 15 global environmental problems are exponentially worsening (Steffen et al., 2015), and that social workers will be unable to ignore these problems when utilising complex systems approaches in their practice. Therefore, the evidence-based knowledge they will seek to inform their advocacy and interventions with clients should be rooted in social work values and derived from the social work profession itself.
Because environmental change shares a complex association with social justice, other professions will potentially begin to implement traditionally social work services and interventions, without the unique social work training that is rooted in cultural competence toward marginalised and oppressed populations. Proctor (2010), offers historical cautionary tales about specific social work sectors (e.g., case management and disaster response) where other professions usurped social work "turf" due to a lacking social work research presence. The results included diminished credibility to the social work profession, its training, proffered services, and outcomes as well as undue risk to vulnerable populations.
The review also yielded positive findings in contemplating how the field moves forward and further engages in environmental and sustainability challenges. First, differing methodological approaches are cited as a barrier to interdisciplinary environmental research (Roy et al., 2013). Though only 18 empirical journal articles were included in this review's final data set, they represented a breadth of research methodologies. Qualitative methods IN SUSTAINABLE DEVELOPMENT THEMES   16   16 were the most frequently cited approach, despite the natural and environmental sciences' reliance on quantitative frameworks (Roy et al., 2013), demonstrating that some barriers are penetrable. The 18 theoretical journal articles also synthesised diverse theories, integrating traditional social work theories with ecological and environmental theories to form robust interdisciplinary conceptual models. While still limited in number, these conceptual and theoretical models should provide the foundations for intervention studies and further empirical research. products, suggesting that the next generation of social work scholars are interested in moving the field forward, and integrating these concepts into their own scholarship. To continue this progress, social work faculty who serve as mentors and advisors need to support these students with receptivity to their pioneering ideas and a willingness to embrace an interdisciplinary approach to mentorship. Building collaborative teams within the field, and across disciplines, is essential.

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Social work researchers interested in the human-environment interface also appear to be making progress within the field of social work as the American Academy of Social Work & Social Welfare (AASWSW) acknowledged the field's response to global environmental change as one of the 12 grand challenges for social work (AASWSW, 2016; . Raising awareness and recognition of the linkages is not enough, though. Future calls to action and theoretical frameworks need to be more effective at stimulating empirical research, and one strategy may be to include specific future directions for research, as well as resources and strategies for overcoming previously noted interdisciplinary research barriers. Global environmental change is the most dangerous crisis facing humanity, and it is critical that much needed social work practitioners are prepared and equipped to intervene in environmental challenges and that social work researchers have clear paths to disseminate their interdisciplinary research. There is also an urgent need for social work intervention research to stimulate change at the macro, mezzo, and micro levels through behaviour change, policy, and advocacy-ensuring a sustainable and equitable usage of Earth's resources.

Disclosure of Conflict Interests
The authors have no conflict interests to disclose.