Green Human Resource Management: An Evidence-Based Systematic Literature Review

: The United Nations’ report “Our Common Future” contributed to underline the crucial role of human resource management in strategically greening the organization and, in turn, economics and society at large. This awareness gave birth to green human resource management (GHRM). Despite the high number of papers addressing GHRM, this topic lacks a proper theoretical, methodological, and empirical systematization. A possible step towards a better understanding of GHRM is an evidence-based analysis of its practices’ outcomes. Developing these reﬂections and considerations, we conducted a systematic literature review on the evidence-based literature about the antecedents and outcomes of GHRM practices, following the PRISMA guidelines. We selected 48 papers. Most selected studies ( n = 25) did not tackle single GHRM activities and processes. Studies considering speciﬁc GHRM areas tackled some dimensions more frequently (e.g., “training and development”, “performance management and appraisal”), while underrepresenting others (e.g., “Job analysis and description”). At the same time, selected studies focused on GHRM consequences for organizations, showing a high adherence to the ability, motivation, opportunity (AMO) theoretical framework. Suggestions for future research are provided.


Introduction
The issue of sustainability became a mainstream topic soon after the publication of the United Nations' Brundtland Report (also known as Our Common Future) in the late 1980s. The report addressed the issue of the need for sustainable development (p. 41), which is "a development that meets the needs of the present without compromising the ability of future generations to meet their own needs" [1]. This definition has been the basis for the development of the concept of organizational sustainability. Organizational sustainability (otherwise known as corporate sustainability), since this issue has been mostly tackled among for-profit organizations, is a broad concept, addressing not only ecological concerns, but also social responsibility and the integration of economic activities with the concern about both the natural and the social environment [2].
'Greening' an organization has an impact on how it deals with its supply chain; the production process; the waste management and production; the organizational culture; and its values, strategies, choices, and employee behaviors, just to mention a few examples.
In the last two decades, the mainstream nature of sustainability and environmental awareness pushed both practitioners and academics to address the issue of human resource management as a strategic tool for greening an organization and, in turn, economics and society at large. In fact, as Wehrmeyer [3] (p. 56) observed: "if a company is to adopt an environmentally-aware approach to its activities, the employees are the key to its success or failure". This explains the rise of a new concept: the green human resource management (GHRM). The social identity theory instead posits that subjects develop their sense of who they are on the basis of their belongingness to some specific groups, such as age group and gender organizational membership [18,22]. Thus, according to this theory, it is possible to assume that employees who develop a green identity at work (no matter whether they are directly involved or not in green practices) will endorse environmentally concerned behaviors which, in turn, will affect the environmental performance of their organizations in terms of sustainability [23].
Since the early 1990s, studies on GHRM covered a broad array of topics, and the last decade saw a tremendous growth of academic articles in this field [21]. The variety of approaches and factors explored by these studies led to an extensive literature review, aimed at describing the state-of-the-art of previous studies, as well as to identify areas still uncovered by the academic literature. From 2011 to 2020, eleven literature reviews were published in peer-review journals.
The earliest work by Jackson and colleagues [24] presented a critical analysis of the main functional HRM practices in the light of a sustainable vision, such as performance management; training, development, and learning; compensation and rewards; and organizational culture. Soon after, Cherian and Jacob [25] dealt with the actual implementation green HR practices in the organization, while the review of Renwick, Redman, and Maguire [5] represented the first attempt to a) observe how HRM and EM are integrated and b) outline future directions of study. A later review carried out by Opatha and Arulrajah [26] aimed at providing a fundamental and updated comprehension of GHRM, underlining the need for conceptualization and operationalization of the various constructs in the field of GHRM, as well as the need for developing valid and reliable instruments to assess the effectiveness of such practices. The work by Ahmad [27] elaborated various green practices that can be incorporated for building a green workplace, while the literature review carried out by Arulrajah, Opatha, and Nawaratne [28] further developed and updated the work by Cherian and Jacob [25], synthesizing the green HRM practices already endorsed by organizations.
Tariq, Jan, and Ahmad [29] moved from the issues raised by the review of Renwick, Redman, and Maguire [5], suggesting the need for addressing new other areas pertinent to GHRM practices, therefore adopting the point of view of "green employee empowerment" for their literature review.
The assumption behind this term is that employees are to be empowered in pursuing green tasks of their organization and that green employee empowerment should be considered under the wider term of green HR.
The review developed by Renwick and colleagues [30] outlined a future research agenda for GHRM, exploring implications for practitioners. They underpinned how the existing GHRM literature may benefit from including national culture; deeper understanding of the green recruitment, as well as the competency and employee participation practices; and a greater focus on linking GHRM to financial and environmental performance outcomes.
Among the most recent literature review, the article of Ren, Tang, and Jackson [4], unlike the previous reviews provided by Renwick,Redman,and Maguire [31] and Tariq, Jan, and Ahmad [29], went beyond the function-based perspective, in order to better tackle the possible connections between specific HRM practices and EM. Ren and colleagues examined the conceptualization, measurement, and theoretical basis developed on GHRM, as well as the antecedents, contingencies, and outcomes of GHRM from the strategic HRM perspective. More in detail, Ren and colleagues showed that GHRM might have green-specific and more general desirable outcomes and potential benefits at organizational and employees' level, such as employees' well-being.
The review carried out by Shahriari, Hassanpoor, Navehebrahim, and Jafarinia [32] analyzed the period from 2009 to 2018 and focused on the definition of green human resource management, highlighting again that there is not yet a clear definition of this term. They also examined how often the GHRM functions are addressed in the literature. More specifically, they found that the functions that received the most attention were selection and recruitment and training and development of green human resources. Their findings also revealed a lack of comprehensive research in undeveloped countries and Asia, as well as the absence of a cross-cultural model. The latest and most extensive review was carried out by Amrutha and Geetha [21]. They covered a wider range of years, from 1995 to 2019, confirming the lack of studies carried out in undeveloped countries, while finding that the majority of studies were carried out in Europe and Asia. Based on their findings, they developed a model aimed at explaining how GHRM practices have an impact on organizational sustainability (in its three facets: environmental sustainability, social sustainability, and economic sustainability) through the mediation of employees' green behaviors at work. Each of these three factors interacts with the corporate social responsibility as well as with contextual factors.
In spite of the relevant literature reviews and the ever-growing corpus of research devoted to GHRM, all the reviews share one point: that the theoretical, methodological, and empirical advancement of the field is still highly required. One of the following steps in further developing the knowledge about GHRM is an evidence-based analysis of its practices' outcomes. Already, previous literature reviews on GHRM [4,21,30] pointed out the need for further understanding the real outcomes of adopting GHRM practices in organizations.

Aims of This Systematic Review
Overall, much of the previous studies in this field dealt either with the awareness, adoption [33], and implementation of GHRM practices in organizations or with theoretical issues, such as the relationship between GHRM and EM and the theoretical foundations of GHRM [4,21]. In most cases, the aim was to identify a future direction for the development of studies on GHRM, adopting a reflective, descriptive, and prescriptive approach.
Building on these considerations, the evidence-based knowledge of the outcome of GHRM practices is important for a number of reasons.
Firstly, there is a strong need for capitalizing the findings on the effectiveness of the GHRM practices in order to understand how to best implement corporate sustainability in organizational actions [2]. GHRM reaches all the functions of HRM, and it is important also to understand which are really working and which are not, and what distinguishes effective GHRM practices from the ineffective ones.
There is a paucity of empirical data in this respect, especially in comparison with the prescriptive literature, describing how organizations should address EM through their GHRM practices and which activities are to be developed [5]. On the other hand, a more factual understanding of the actual effects of GHRM practices can play a role in further promoting the wider adoption of EM and GHRM practices in the organization. The dissemination of the positive results of practices already endorsed may lead managers to replicate these same practices in their organizations, therefore further developing their green approach.
As Ren and colleagues noted [4], "designing and implementing GHRM practices requires major investments in organizational resources, likely leading managers to question whether such investments are worthwhile" (p. 20). It is important to stress that the GHRM practices are implemented mainly as mandatory activities by the management. Therefore, the knowledge about the real efficacy of these practices by the managers can make the difference between going green or not [21].
Secondly, a review of empirical, evidence-based findings is necessary to understand other, more general, desirable outcomes beyond the ecological and environmental benefits. There is a need to advance scholarship and practice, and to comprehend how GHRM practices have an impact on the environmental attitudes and behaviors of the organization's staff [30].
For instance, there are assumptions about the consequences of adopting green initiatives on employees' well-being and organizational behaviors [34,35]. Similarly, it is often hypothesized that developing a green identity at work is positively associated with the endorsement of green attitudes and behaviors also outside the workplace [36], but these outcomes are yet to be verified and may constitute a further factor for assessing costs and benefits of introducing green initiatives in an organization.
Thirdly, the actual knowledge of the results achieved is necessary to contextualize the GHRM practices and to capture and explain their complexity, ambiguities, and uncertainties across different contexts, as pointed out by Ren and colleagues [4]. In fact, contextual conditions and employee characteristics may intervene, shaping or moderating the effects of GHRM practices, both in the short and long-term.
Therefore, assuming as a starting point the conclusion reached by the previous literature, we developed a review of the empirical, evidence-based literature about the antecedents and outcomes of GHRM practices.

Methods
The paper selection process was conducted in accordance with the preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement [37]. Eligibility criteria were fixed so that empirical studies published in peer-reviewed full-length articles from 2005 to 2020, written in English, were selected for this review. The chosen publishing time range was due to the acknowledgment that a skyward trend interested in GHRM papers from 2005 to 2020, probably due to the diffusion (firstly in Europe and Northern America, then in Asia and South America) of specific legislation [21]. The period of literary research lasted from April to May 2020.

Information Sources and Search Strategy
Databases and search engines employed for the search were: EBSCOhost, ProQuest, and Web of Science. Each database required a different detailed strategy. At the same time, the following generic combination of keywords covered the focus of our research: • (green or environmental or sustainable) and ("human resources" or "human resource management" or HRM).
According to the needs, the keywords were searched in the publication title or abstract.

Data Collection Process
All references were gathered in a Mendeley database. Selected references were independently reviewed by two authors, who selected the final list of documents to be analyzed. As the chosen databases allowed to preselect full-text availability, year, and language of publication, this manual selection procedure mainly regarded paper content. Papers in which the content was not fully within the scope of this review (e.g., theoretical position paper, prescriptive approaches, best practices) and did not include empirical research were eliminated. Furthermore, the authors scrutinized the reference section of selected papers, looking for further works written in English that could fit the eligibility criteria and, eventually, read their abstracts to check whether they could be included in the review. Figure 1 shows the whole workflow that brought about the final paper selection.

Study Selection
After applying the inclusive and exclusive criteria (Figure 1), 48 papers were determined as eligible and were included for review (see Table 1 for a description of study characteristics, participant characteristics, and the description and role of GHRM). y Selection er applying the inclusive and exclusive criteria (Figure 1), 48 papers were determ and were included for review (see Table 1 for a description of study charact nt characteristics, and the description and role of GHRM).

Study Characteristics
The first paper tackling green HRM in an empirical investigation was published in 2012 (n = 3), showing an increasing trend until 2020 (n = 15). Figure 2 shows this trend in detail.

Study Characteristics
The first paper tackling green HRM in an empirical investigation was published in 2012 (n = 3), showing an increasing trend until 2020 (n = 15). Figure 2 shows this trend in detail. Regarding the countries involved, Asian countries were the most represented in the selected studies (n = 37). Consistently, most studies were conducted in China (n = 10), followed by Malaysia (n = 7) and Pakistan (n = 6) (see Table 1 for more details).
Regarding the type of organization involved, profit organizations were the most represented (n = 42). Consistently, the most involved organizations were manufacturing firms (n = 32), followed by hotels and restaurants (n = 7), health services (n = 3), university campuses (n = 3), and banks (n = 1). Two papers did not provide information about the type of organization involved.
Regarding participant characteristics, the majority of the selected papers (n = 32) gathered data from employees, followed by studies with managers (n = 11), studies with both (n = 4), and with HR academic experts (considered at the same time as experts and employees, n = 1).
Regarding the study methodology, 44 studies used quantitative methods, two used qualitative methods, and two used mixed methods.

Conceptualizations of GHRM
A first consideration has to be made on the GHRM construct definition used in each paper. Among the selected papers, 25 out of 48 did not specify dimensions or areas to describe GHRM practices. The remaining 23 accounted for different GHRM dimensions. Among these, while several papers (n = 16) included measures accounting for all the GHRM dimensions [5,24,29], a few others (n = 7) focused on specific dimensions, or used a specific theoretical background to reorganize the construct dimensions [38]. Despite using slightly different lexical options (e.g., compensation vs. pay), the studies allowing for a more precise description of the GHRM effects agreed on a number of dimensions. In this regard, it is possible to enumerate some common GHRM practices implemented in the analyses: job analysis and description; selection, recruitment, and hiring; performance management and appraisal; rewards, pay, and compensation; training and development; involvement and empowerment. Overall, the studies considering different GHRM dimensions, even  Regarding the countries involved, Asian countries were the most represented in the selected studies (n = 37). Consistently, most studies were conducted in China (n = 10), followed by Malaysia (n = 7) and Pakistan (n = 6) (see Table 1 for more details).
Regarding the type of organization involved, profit organizations were the most represented (n = 42). Consistently, the most involved organizations were manufacturing firms (n = 32), followed by hotels and restaurants (n = 7), health services (n = 3), university campuses (n = 3), and banks (n = 1). Two papers did not provide information about the type of organization involved.
Regarding participant characteristics, the majority of the selected papers (n = 32) gathered data from employees, followed by studies with managers (n = 11), studies with both (n = 4), and with HR academic experts (considered at the same time as experts and employees, n = 1).
Regarding the study methodology, 44 studies used quantitative methods, two used qualitative methods, and two used mixed methods.

Conceptualizations of GHRM
A first consideration has to be made on the GHRM construct definition used in each paper. Among the selected papers, 25 out of 48 did not specify dimensions or areas to describe GHRM practices. The remaining 23 accounted for different GHRM dimensions. Among these, while several papers (n = 16) included measures accounting for all the GHRM dimensions [5,24,29], a few others (n = 7) focused on specific dimensions, or used a specific theoretical background to reorganize the construct dimensions [38]. Despite using slightly different lexical options (e.g., compensation vs. pay), the studies allowing for a more precise description of the GHRM effects agreed on a number of dimensions. In this regard, it is possible to enumerate some common GHRM practices implemented in the analyses: job analysis and description; selection, recruitment, and hiring; performance management and appraisal; rewards, pay, and compensation; training and development; involvement and empowerment. Overall, the studies considering different GHRM dimensions, even when not directly addressing the AMO theory, can be reorganized in light of this theoretical framework, confirming previous considerations [5,21,30], as shown in Table 2. Each dimension was associated with several employee-related and organization-related antecedents and outcomes, as reported in Table 3.
With reference to the studies addressing specific GHRM dimensions, employee training and development and involvement and empowerment were frequently associated with significant outcomes. These dimensions include practices aimed at providing employees with the knowledge required to adhere to green organizational policies and practices (namely, training and development) [39], and at creating a context in which employees can effectively engage in green behaviors (namely, involvement and empowerment) [9]. In the selected papers, these practices were reported to have a significant effect on green organizational outcomes, such as sustainability [40], environmental commitment [41], environmental performance [42], and supply chain management activities [43]. Interestingly, the training and development dimension was mentioned even in papers addressing one to three GHRM dimensions [42,44]. Rewards, pay, and compensation is another dimension frequently linked to significant outcomes. It is defined as the set of financial and nonfinancial rewards aimed at stimulating green employee behaviors and reinforcing long-term organizational outcomes [45]. Consistently, the selected papers reported significant effects of this dimension on organizational sustainability [46], environmental performance [42,47], and green supply chain management [43]. At the same time, all these dimensions have been linked to employee-related outcomes, such as higher green commitment [35,41,48] and lower turnover intentions [49]. Finally, even the green selection and appraisal procedures were frequently liked to significant outcomes. Most specifically, studies showing a specific effect of the selection, recruitment and hiring" dimension were mostly related to organizational consequences, regarding organizational sustainability as perceived by managers and employees [40,46]. Studies reporting a significant effect specifically related to the performance management and appraisal dimension mainly regarded perceived environmental performance [42] and employee commitment towards green issues [50].
Overall, the selected papers show a high frequency of quantitative studies addressing the organizational consequences of implementing GHRM practices in different types of organizations. The prevalence of organization-focused and consequence-oriented papers was confirmed across geographical areas. Figure 3 shows a graphical synthesis of the main organization and employee-related antecedents and consequences, with main mediators and moderators.     Overall, the selected papers show a high frequency of quantitative studies addressing the organizational consequences of implementing GHRM practices in different types of organizations. The prevalence of organization-focused and consequence-oriented papers was confirmed across geographical areas. Figure 3 shows a graphical synthesis of the main organization and employeerelated antecedents and consequences, with main mediators and moderators.

Organizational and Employee-Related Antecedents of GHRM
In the remaining 15 studies, green HRM was studied as a consequence of organizational (n = 11) or employee-related (n = 3) dimensions. Among these, only two studies addressed both organization and employee-related antecedents at the same time. In one study, GHRM was described as not having significant effects on the studied dimensions. Common organizational dimensions reported as antecedents were related to green organizational culture [51,52] and strategies [15,53]. Evidence was given on the role of leadership styles [38,54] and relationships with external stakeholders [40,42]. The three papers addressing employee-related antecedents to GHRM showed the effect, respectively, of green human capital [40], green academic knowledge [55], and green behaviors [56].

GHRM Consequences on Organizations
Thirty-three studies considered green HRM consequences at organizational-(n = 29) or employee-level (n = 17). Among these, only four studies addressed the effect of green HRM on both organization-and employee-related dimensions at the same time [23,52,57,58]. Environmental performance was the most mentioned (n = 15) effect of GHRM on the organizational level, both in studies with employees [23,59,60] and managers [42,61]. In these studies, the effect of GHRM on environmental performance was frequently influenced by organizational practices and strategies, namely leader's emphasis and credibility in addressing green issues [62], top management commitment [61], and green supply chain management [59,60]. At the same time, the GHRM effect was reported as influenced by employee dimensions, such as personal values [57], personal motivation in pursuing green behaviors [63], and green organizational citizenship behaviors [47,64]. Finally, other studies reported a direct effect on GHRM practices on organizational environmental performance [52,65,66]. Another organizational effect reported in literature regarded green innovation and sustainability (n = 7). In this case, the effect was either direct [40,43] or influenced by management environmental concerns and green human capital [58].

GHRM Consequences on Employees
Regarding employee-related outcomes, green behaviors and green organizational citizenship behaviors (OCB) at work were the most mentioned consequences (n = 8). In this case, GHRM effect was always influenced by other dimensions, including those related to organizational practices, namely green climate [67], green feedback and goal setting [68], and green performance management [35]; and to employee-related aspects, namely organizational identification [69], affective commitment [41], environmental knowledge [70], green psychological capital [48], and personal values [57].

Discussion
This systematic review revealed a heterogeneous research approach to the study of GHRM practices within organizations. Selected studies showed different choices in terms of GHRM conceptualizations and dimensions selected for the analyses, focus on antecedents vs. consequences of GHRM practices, and focus on organizational vs. employee-related effects. Despite these differences, it is possible to enucleate some trends.

Chronological and Geographical Trends
Firstly, a chronological trend emerged, with most studies published from 2018 onwards. The chronological distribution of selected papers doubles the trend of theoretical and prescriptive papers on these topics, showing a constantly increasing tendency to tackle GHRM from an empirical perspective [21]. Secondly, a geographical trend arose, too, with an increasing number of studies published in emerging countries over time (over 90% of the papers selected for this review). Both trends could be explained in light of the increasing awareness from international institutions and policy-makers towards green management. As underlined by Amrutha and Geetha, indeed, the number of papers tackling GHRM over time, as well as their geographical distribution, were strongly influenced by regulations on sustainability and ecological standards across organizations [21]. As Asian and South American countries tackled these topics more recently, the overall number of papers, as well as the higher involvement of organizations working in those areas, resulted in an increased spreading of evidence-based papers.

Dimensions of the GHRM Construct
A third consideration regards the GHRM construct. From the selected papers, current research on GHRM emerges as not providing evidence for all the dimensions usually ascribed to the GHRM construct. As shown in Table 2, training and development is tackled most frequently, followed by performance management and appraisal; reward, pay, and compensation; and selection, recruitment, and hiring. Job analysis and description, instead, is almost neglected, with four mentions out of 48 papers [46,53,62,71]. This point calls for two considerations. Firstly, more studies tackling all the GHRM dimensions are needed to provide effective and useful indications to organizations when addressing the development of human resources at any stage of their work within the organization. By considering and evaluating a broader range of GHRM activities, researchers and managers would have a higher awareness of which activities are more effective in general, as well as in specific cultural and organizational contexts (e.g., manufacturing firms vs. nonprofit organizations). Secondly, it is interesting to notice that, among studies including all the GHRM dimensions in their analyses, papers reorganizing the GHRM construct arise. This is the case for Anwar and colleagues [47], Pinzone and colleagues [41], and Singh and colleagues [38]. Despite using different methods, all the papers converged towards a similar classification. Anwar and colleagues differentiated a competence dimension (recruitment and training), a motivation dimension (performance and rewards), and an employee involvement dimension. Similarly, Pinzone and colleagues distinguished competence building, performance management, and employee involvement in GHRM practices [41]. Despite producing a classification similar to Anwar (et al.)., the authors did not use the original GHRM construct to reach their final scales. Finally, Singh and colleagues used the AMO framework to reorganize the construct, so that the ability dimension included recruitment and training procedures, the motivation dimension included performance appraisal and rewards, and the opportunity dimension included employee involvement practices [38]. It is apparent that the GHRM dimensions included, as well as the distinctions and rearrangements, are substantially identical to one another. Overall, such classifications confirm the saliency of certain dimensions, as well as the centrality of the AMO framework in describing them. At the same time, it remains unclear whether other dimensions of GHRM are neglected because they do not fall easily within the mentioned frameworks or because of other reasons.

GHRM Organizational Outcomes
Overall, studies addressing organizational outcomes of GHRM practices, whether in terms of a general score or considering specific dimensions, better fit in the AMO framework. According to AMO, indeed, when organizations provide an employee with new abilities, higher motivations, and higher opportunities to implement green behaviors and commit to environmental sustainability, then they increase their chances to reach a better green organizational performance [38,47]. According to Purcell and colleagues, employee commitment and discretionary behaviors are crucial to constructing the link between HRM practices and organizational performance [72]. The authors, indeed, state that the higher the employees are motivated and committed towards certain behaviors, the higher the spread of practices linked to those behaviors in the organization. Selected papers showed similar effects with employee green behaviors and green organizational performance, above all when considering GHRM as a mediator between the two [56]. Even studies addressing GHRM effects on both employee and organizationrelated outcomes are strongly connected to this framework, for example, when considering in the same model the GHRM influence on both green employee behaviors and organizational performance [23,57].

Main Conclusions, Limitations, and Future Directions
Overall, this literature review contributes to shed new light on how GHRM could be implemented, which organizational and employee-related dimensions influence its implementation, and which organizational and employee-related outcomes arise from it by systematizing current knowledge on these topics. Considering the high number of theoretical and prescriptive papers on GHRM [5], as well as the financial and nonfinancial resources required to implement it [4], indeed, both researchers and practitioners may benefit from a synthesis of current research results, in order to verify the actual effects of GHRM practices and spread their adoption. Furthermore, this review contributes to individuate employee-related antecedents and consequences of GHRM practices, thus providing more information on how employees could be involved in green activities and how they could impact the green performance of the organization. Summing up, this review informs that: (1) Research works on GHRM show a chronological trend, with most papers published from 2018, and a geographical trend, with most papers published with data from emerging countries.
(2) There is still a high heterogeneity on GHRM conceptualization, with half studies addressing GHRM a single construct, and half considering more dimensions. (3) Among studies considering more dimensions, training and development; performance management and appraisal; reward, pay, and compensation; and selection, recruitment, and hiring are the most tackled. (4) Most studies tackle organizational outcomes, failing to address individual, employee-related GHRM effects; studies tackling organizational outcomes of GHRM fit in the AMO framework.
At the same time, this work is not without limitations. First, our eligibility criteria excluded non-English papers-it is plausible that research works written in different languages would have given a salient contribution to this review. Secondly, we excluded conference proceedings, thus potentially losing important information about ongoing studies and interventions on GHRM. Finally, to the best of our knowledge, we considered all the eligible papers given our selection criteria, but it is possible that some papers were missed.
With reference to further studies and applications, although helpful, available evidence-based literature on GHRM could be extended by acknowledging and tackling some uncovered issues, in order to avoid the "organization as a black box" effect, described by Howard-Grenville [73], namely the lack of understanding of the contexts and culture that guide the organization. Firstly, researchers and policy-makers would benefit from the use of data aimed at contextualizing GHRM practices and their antecedents and consequences on organizations and employees. For example, it would be helpful to gather data on the dimensions and the culture of the organizations in which GHRM is implemented to individuate specific GHRM actions that would better fit specific contexts. Secondly, most of the papers included in this review (except the ones in the banking and educational sectors) gathered data from profit organizations, thus indicating an underrepresentation of GHRM practices in nonprofit and public contexts. It would be interesting to tackle these organizations, to verify whether the current lack of evidence-based information is due to a low commitment to the green issues, or to low interest from researchers. Thirdly, information about the macrofinancial, social, and cultural context in which the organizations operate would help better situate the organizational efforts towards a greener performance. In other words, future research could focus on the organizational aspects that, despite not being causally related to GHRM, influence its implementation and outcomes. Finally, despite the high number of prescriptive and descriptive papers regarding GHRM, current evidence-based studies on GHRM antecedents and consequences for employees and organizations show a focus on specific GHRM dimensions, in specific countries and types of organization. Such peculiarities call for a better understanding of what GHRM implies for managers and employees; what kind of requirements poses to the organization, as well as to the daily employee behaviors; and how it tackles organizational and individual needs and motivations. Furthermore, such considerations could regard governmental and nonprofit organizations, as well as profit organizations based in Europe or the USA. It seems plausible that stronger use of qualitative methods would help researchers and practitioners answering these questions and, if needed, help in revising the GHRM concept and how it is applied in research and intervention.