1. Introduction
The nexus between the quality of the natural environment and well-being, often equated with happiness, is an important one in sustainability [
1], and there is a growing body of literature on this topic. Ferrer-i-Carbonell and Gowdy [
2], for example, looked at the relationship between well-being and environmental quality, and noted that “
positive environmental features (e.g.,
nature landscapes, interaction with plants and wildlife)
is positively connected with well-being” [
2] (p. 515). Studies can be broadly categorized into two types. Firstly, there are the individual reports (self-assessments) of well-being (or happiness) when people are in different places, including natural habitats and greenspace (urban parks, etc.). These studies often make use of software apps for people to record how they feel, and the assessments can be readily geolocated [
3]. The results of such individual assessments are largely unambiguous as people tend to feel happier and ‘better’ when in natural habitats and greenspaces compared to urban environments [
3,
4]. There have been various mechanisms for explaining a positive link between a sense of happiness or well-being and the natural environment. For example, MacKerron and Mourato [
3] suggested that, as natural environments are generally perceived to be lower in pollution, this can have positive impacts on both physical and mental health. Being in natural habitats and greenspaces can also be associated with healthy behaviors, such as exercise, recreation, and social interaction.
Secondly, and especially since the 1990s, economists have employed country-scale datasets to analyze the linkages between a variety of environmental indicators and well-being, both within and across countries and time [
5,
6,
7]. When it comes to indicators designed to capture dimensions, such as pollution, and availability of resources, such as clean air and water, the correlations with well-being tend to be positive and straightforward; less pollution results in a better sense of well-being. However, studies have often generated mixed sets of results between the extent and quality of natural habitats and a variety of socio-economic indicators including those that capture a sense of well-being [
8]. In their exploration using panel data derived from a survey of a link between urban resilience—defined in terms of ecological resilience, infrastructure resilience, social resilience, and economic resilience—and subjective happiness in China, Liao et al. [
9] noted that these were positively correlated; better resilience generates a better sense of happiness. However, studies that are based on panel data collected from a range of countries can often vary in terms of their findings. For example, in a recently published study [
10] using data from 124 countries the authors concluded that: “
Ecosystem Health, Biodiversity, Long-Term Climate Stability, and Clean Energy were not found to be significantly related to nations’ well-being… Arguably, the less tangible measures such as Ecosystem Health, Biodiversity and Long-Term Climate Stability refer to complex phenomena that may partly go unperceived by individuals. In addition, the bulk of effects that follow from their deterioration will occur in the future rather than at present.” [
10] (pp. 13–14). In this paper, well-being was assessed at the country-scale using the Life Ladder Scores (LLSs) published in the World Happiness Reports (WHR), and the analysis included a number of socio-economic ‘pillars’, such as Inclusion, Social Cohesion, State Capacity, Individual Capabilities, Economy, and Civic Space that were also considered to be important for ‘state resilience’ alongside the environmental indicators [
10].
Given the points made in the quotation above from Welsch [
10], a degree of ambiguity between well-being and indicators designed to capture facets of habitats, such as protection and biodiversity, in country-level studies is perhaps understandable. For example, a paucity of direct contact between people who live in urban contexts and more geographically distant natural habitats could potentially be an issue when it comes to framing perceptions. With studies based on asking individual respondents how they feel when in natural habitats, and indeed in urban greenspaces, compared to being in other environments, then an association can be clearly identified [
3]. However, with the country-scale studies that draw upon large yet separate datasets, the connections between perceptions and the extent and quality of natural habitats may be far less clear. Araújo et al. [
8] have noted that the establishment of protected habitats may not necessarily be perceived by all communities as positive, especially if it deprives people from access to important resources (e.g., land, firewood) and thereby threatens their livelihood. Finally, even if the linkages between people’s perceptions of well-being and indicators designed to assess the quality of natural habitats are identified then these could be due to other mediating factors, such as the quality of governance. For example, Toigo and de Mattos [
11] explored the relationships between a suite of country level environmental indicators and how they were correlated with well-being as well as indicators of the quality of governance, such as those that assess corruption. They found that countries having better environmental performance also tend to have better governance, and this is correlated positively with well-being; better governance was also positively correlated with measures of environmental performance. Tandoc Jr. and Takahashi [
12] found that well-being was positively related to press freedom (as assessed by a group of experts) which is also linked to governance. Indeed, the WHR, published annually by the Wellbeing Research Centre at the University of Oxford, in partnership with Gallup, the UN Sustainable Development Solutions Network, often includes corruption as an explanatory factor for happiness [
13]. Hence, when measures of well-being or happiness are positively correlated with indicators that assess the quality of natural environments, then the key question is whether this is a direct cause–effect or are these two simply reflections of an underlying quality of governance [
11]?
This hypothesis of a link between governance, natural habitats, and happiness could be explored in various ways. For example, the Environmental Performance Index (EPI) provides an opportunity to study these links, given that it comprises many indicators designed to capture aspects of natural habitats, and it can be hypothesized that some of these may be more closely linked to governance than others. The EPI reports are published biannually, and while the Index has been used to explore links with happiness [
11,
14], this has typically been undertaken using the Index rather than disaggregating into component indicators. However, the EPI is a complex index comprising 24 indicators in the 2018 version and 58 indicators in 2024, each having their own weightings. Of the indicators that comprise the EPI, there is a group that have appeared in all the reports from 2018 to 2024 which seek to capture various aspects of the quality of natural habitats, and which could be hypothesized to have a degree of association with the quality of governance [
15]. These are as follows:
Terrestrial Biome Protection based on national weights (TBN)
Species Protection Index (SPI)
Protected Area Representativeness Index (PAR)
Species Habitat Index (SHI)
The first three in the list (TBN, SPI, and PAR) can be described as ‘habitat/species protection’ indicators, and the ‘polarity’ is such that higher values for the indicators equate to ‘better’ protection of species and habitats. The TBN is designed to assess a country’s efforts to protect its terrestrial biomes, although the definition of what is meant by a biome and the classification of biomes are somewhat complex and contested [
16,
17]. Data for the TBN are sourced from the World Database on Protected Areas (WDPA), where a protected area is defined by the International Union for Conservation of Nature [
18] as “
a clearly defined geographical space, recognized, dedicated and managed, through legal or other effective means, to achieve the long term conservation of nature with associated ecosystem services and cultural values”. The value of the TBN is found by calculating the proportion of each biome in a country that is located within a protected area, with a higher ‘weighting’ given to biomes that are relatively rare in the country. Higher TBN values suggest that the country is better at protecting its various biomes. The SPI is an indicator designed to capture the effectiveness of protected areas in terms of conserving suitable habitats for terrestrial species. The SPI is derived as the average of the Species Protection Score (SPS) for individual species based on how much of its species range or population is in protected areas as defined above. For example, if 50% of a species range was within protected areas, then the SPS would be 50. Higher SPI values suggest, on average, that there is better protection of species within the country. The PAR assesses how well a country’s protected areas reflect its ecological diversity, with higher values suggesting a better reflection of ecological diversity. All three of these indicators can be assessed, at least in part, using data derived from remote sensing techniques. While there are limitations with the use of remote sensing, including earth observation via satellites, there has been something of a surge in the availability of higher resolution (<1 m) imagery in recent years that can provide a valuable resource [
19], especially when used in combination with techniques such as machine learning [
20,
21]. Perhaps more relevant here is that all three of these indicators are based on the concept of ‘protected areas’ and thus have at their heart a degree of active engagement by government and its agencies in the protection of biomes, habitats, and species. Hence, there is logic in expecting these ‘protection’ indicators to be positively associated with the quality of governance, as protected areas and species need to be identified and demarcated as well as requiring ongoing monitoring and management to ensure that the protections are maintained.
The SHI is different from the other three EPI indicators (TBN, SPI, and PAR) in that it is designed to assess the proportion of suitable habitats for a country’s species that remain intact relative to a baseline year (i.e., 2001) [
22], although this is not necessarily tied solely to protected areas. It is calculated for each species before being aggregated, and a weighting is used to reflect the proportion of the global range of a species found within the country (i.e., a stewardship weighting). Higher SHI values suggest less habitat loss compared to the reference year. The SHI reflects various facets important to species, such as the quality and size of their habitat as well as their degree of fragmentation and connectivity. The rationale is that, as habitats shrink, degrade (e.g., lose biodiversity), or perhaps become more fragmented with little in the way of corridors connecting the fragments, the species that depend on them are likely to decline and may even become locally extinct. Therefore, the SHI can be regarded as a measure of habitat intactness [
22] and habitat condition [
23], and is used as a proxy indicator of ecological integrity [
24], species abundance [
25], and biodiversity [
10,
23,
26,
27,
28]. As with the other indicators discussed above, the SHI is assessed using remote sensing based on the natural growth of vegetation over space [
28,
29]. However, the SHI does have its critics when used to proxy characteristics such as biodiversity: “
While indices such as the Red List Index and the Species Habitat Index are widely recognized, they may not fully capture the multidimensional nature of biodiversity or localized ecological nuances.” [
23] (p. 18).
The forces at play in causing such a decline in the extent and quality of habitat include pressures for development (urbanization, deforestation for agriculture, and plantations) [
26,
28,
30] as well as factors outside the control of a country, such as climate change. A government can, of course, act to limit declines in both habitat condition and extent as well as the prevention or reversal of fragmentation [
31] and introduce mitigations such as the establishment of corridors between fragmented pieces of habitat. Indeed, the period called the ‘Great Stagnation’ following the Great Financial Crisis of 2008/9 [
32] has witnessed a negative impact on biodiversity globally, although some have pointed to a small increase in the SHI [
29,
33]. However, loss of natural habitat may be popular with the public if it addresses needs for more housing and employment opportunities as well as increasing consumption of agricultural products [
26]. Hence, the SHI is arguably not a measure of the effective protection of biomes and species, as are the TBN, SPI, and PAR [
29]. This division between the SHI and a ‘protection’ group of indicators (TBN, SPI, and PAR) is a variant on the classification derived by Gareiou et al. [
34], who regarded all these indicators as being within a ‘Biodiversity and habitat’ category, and indeed they can be grouped that way as they all share that general theme.
The question at the heart of the research reported here is whether there is a difference between the ‘protection’ group of indicators and the SHI in terms of their relationship with the quality of governance and with well-being/happiness. Based on the broad hypothesis set out by Toigo and de Mattos [
11], it would be expected that the habitat/species ‘protection’ group of indicators would have a positive correlation with governance and therefore with well-being; in effect, well-being and the ‘protection’ group of indicators are both influenced by the quality of governance. Following this same logic, is the pattern the same for the SHI? Assuming that the SHI may not be so directly tied to the quality of governance, then does this result in a different relationship between the SHI and well-being? If there are differences between the habitat/species ‘protection’ group of indicators and the SHI in terms of their relationship to well-being, then this could potentially offer support for an indirect influence arising from the quality of governance as set out by Toigo and de Mattos [
11].
4. Discussion
There are various ways of explaining the different relationships between the indicators of habitat quality and the LLS summarized in
Figure 2. Taking as a foundation the findings of Toigo and de Mattos [
11] that environmental performance (i.e., the EPI) as well as well-being are both positively influenced by the quality of governance, then one explanation is that the habitat/species ‘protection’ group of indicators and well-being are also positively influenced by governance. Hence, what is seen in
Figure 2 is really the influence of an underlying quality of governance on both the habitat/species ‘protection’ group of indicators and self-reported well-being, with income perhaps being a mediating factor (i.e., higher income helps create better well-being). Hence, for many of the respondents to the GWP survey, their self-reported well-being may not be influenced directly by the group of ‘protection’ indicators; what they are responding to is the quality of governance. Given that the habitat/species ‘protection’ indicators are also influenced positively by governance, then that would help explain the apparent association between those indicators and well-being, but this may not be a direct ‘cause–effect’.
However, the negative association between the SHI and well-being shown in
Figure 2 does not at first glance fit with the explanation set out in the previous paragraph. The SHI is not influenced by the quality of governance, and perhaps this can be explained as the SHI is more a reflection of habitat intactness [
22] and condition [
23], and much of that habitat within a country may not necessarily be in protected areas. Government does have a role, of course, in helping to limit habitat loss and to introduce mitigations, such as habitat corridors [
26], but governments are often under competing and often strong social and economic pressures to allow changes in land use [
23,
26,
30]. The habitat/species ‘protection’ group of indicators are different in this regard; all three of them relate to protected areas that have been demarcated, protected, and managed with government input and oversight, including legal designations. Therefore, it is perhaps unsurprising that the SHI does not share the same degree of influence from governance as does the ‘protection’ group of indicators.
However, there remains the statistically significant but negative association between the SHI and self-reported well-being to explain. It could be that self-reported well-being is a reflection of other factors, such as shifts in land use towards housing, agriculture, and industry (hence employment). These changes in land use could have a negative impact on the SHI, and that would help explain why there is a negative association between the SHI and well-being. In effect, the SHI may be a reverse indicator of perceived ‘development’. This is, admittedly, supposition, but it is a potentially important and intriguing hypothesis that would warrant more research. The perception of impacts arising from land-use changes are likely to be complex and highly site-specific, with communities living in or near natural habitats reporting negative views, while others may see them as much more positive, but it does need to be noted that the GWP sampling frame does not take account of such intra-country locational differences when selecting respondents to its survey. It is known that the SHI is positively and significantly associated with human capital, suggesting that citizens’ awareness and cooperation may be more influential when it comes to maintaining habitat than are physical investment and political institutions [
47], but perhaps it also matters where that human capital is located.
There is much relevance here for future work in the field of the relationship between the quality and extent of natural habitats and well-being at these country-level scales. The complex nexus between aspects of environmental quality, governance, and happiness sits at the heart of much policymaking, but matching diverse data sets in terms of their focus and methodology remains a challenge. One way forward would be to work with the indicators that comprise the EPI, as shown here with the TBN, SPI, PAR, and SHI indicators, rather than the aggregated index, which has been the approach taken by many when exploring the relationship between the EPI and social and economic indicators [
48]. Working with such a complex, and methodologically variable index and using that to relate to well-being or indeed to governance can result in the loss of much information. Secondly, the differences between the ‘protection’ group of indicators and the SHI in terms of their apparent association with self-reported well-being do need to be explored further, especially in terms of the potential explanations set out here. There is much logic in the assumption that the ‘protection’ group of indicators are influenced by the quality of governance, and this would help explain their apparent relationships with self-reported well-being. The pattern for the SHI and for well-being is very different, and this needs much more unpacking. Is the SHI really an inverse indicator of land-use change, and thus people’s perception of ‘development’? Maybe a first step would be to explore how land-use change influences people’s perceptions of ‘development’, although this can be expected to be highly context-specific. If this is the case, then a next step would be to explore how these land-use changes impact on people’s perceptions of their well-being. If these hypothesized relationships can be proven, then the notion of the SHI being an inverse indicator of perceived development, and hence well-being, would have a theoretical foundation. However, it is likely that such studies will need to take a more intra-country approach with trends explored over time, perhaps involving a smaller sample of countries. Another approach would be to explore variation in the relationships between the WGIs, the EPI, and self-reported well-being indicators based on geopolitical categorizations (regions, continents, level of development, etc.). Given how important well-being is in terms of influencing people’s behavior and the impacts that may have on processes such as biodiversity loss and climate change, such a comparative ecology of well-being would be well worth the effort.