Health Behavior and Planetary Health

At the moment of writing these lines, most part of the world faces an unexpected pause in normative daily-living activities. This generalized social containment (and quarantine or isolation, for some), together with effective COVID-19 screening systems, seems to be the unique solution to fight against coronavirus, at least, presumably, until vaccination or other pharmaceutical interventions prove to be effective to control the pandemic. What seems to be a solution to go back to the world’s typical epidemiological curve trends, also provides a forecast of what may be required, in a relatively short period of time, to face environmental challenges, including climatic changes.

This sudden disruption of worldwide social and economic activities has tremendous impacts, such as fear of contamination, loneliness, boredom, physical activity and food behavior changes, financial loss, among others. All these social containment related stressors, although being adaptative reactions to a pandemic, may act as determinants of post-traumatic stress, anxiety disorders, or depression (Brooks et al., 2020), burnout (Barello et al., 2020), marital conflicts (Zhang, 2020), unbalanced food behavior and reduced physical activities (Ammar et al., 2020), among other mal-adaptive responses. Paradoxically, this tremendous deceleration of regular human life also correlates with notorious improvement in several environmental indicators, such as air pollution (The Guardian, 2020) or (most probably) traffic-related noise, among others. This is an outstanding illustration of how human behavior and lifestyles can act as main determinants of a multiplicity of outcomes related to human health and the natural environment. And surely illustrates the intertwined relationships between gains in human longevity and well-being, and natural systems health, expressed in the current definition of planetary health (Whitmee et al., 2015a).

Health Psychology and Environmental Psychology: Two Worlds Apart?

Health psychology and environmental psychology have roughly the same age, as specific and independent applied psychological disciplines (Matarazzo, 1980; Richards, 2000). Over these last 50 years (a little bit more for environmental health), these two disciplines made their path with much fewer moments of dialogue than it would be expectable. Indeed, up till recently, research objects and problems from each of these two areas of psychological knowledge were mostly from different arenas: health psychology has been dedicated to the study of health and disease-related behaviors (Shumaker et al., 2009), whereas environmental psychology has been mostly concerned with how the environment can promote higher levels of well-being and life satisfaction (Gärling, 2014). It is not too risky to say that a good share of the history of environmental psychology was dedicated to the understanding of how natural or constructed environments (e.g., cities, gardens, housing) impacted human identity, attitudes or behaviors, whereas health psychology has been focused on how to stop unhealthy behaviors and how to form healthy habits (e.g., regular physical activity, treatment adherence). It is, therefore, natural that research questions and methods tend to differ also between these two areas: integration of analytic methods from architecture, planning, design, or sociology with psychology, for environmental health (Gärling, 2014); theories of behavior and behavioral change or maintenance, economic behavior, for health psychology (O’Cathain et al., 2019; Shumaker et al., 2009). Only more recently the focus of environmental health started to shift also to human behavior as a source of environmental problems (Gärling, 2014).

We believe that the history of these two disciplines of psychological thought needs to converge so that psychological science can assume a more active and efficient role in fighting against syndemic phenomena (Singer, 2009), namely syndemics involving environmental changes. A good example of a problem that requires health and environmental psychology to put efforts together is what Swinburn et al. (2019) called the global syndemic of obesity, undernutrition, and climate change. Each one of these global problems interacts with the other two and all of them have an underlying common determinant: human behavior. Likewise, and as will be discussed later, changing human behavior for the greater good (i.e., individual long-term health and environmental protection), and for coping effectively with syndemics, requires a different level of action, including both intra-individual and environmental modifications. Therefore, both health psychology and environmental psychology are active ingredients in this debate.

A Third Scientific Actor in the Discussion of Human’s and Nature’s Health: Environmental Health Research

When thinking about the relationship between the environment and human health, it is impossible to forget the scientific field of environmental health. It is interesting to note that this is an area of research where only recently psychologists started to be involved. Environmental health has been (and still is) dominated by the so-called hard sciences (e.g., chemistry, physics) and biomedical research. Because of this, researchers working in this area of study tend to be (mainly) epidemiologists, chemists and biochemists, biologists, climatologists, sanitary engineers, geographers, urbanists, and architects. Psychologists are much less frequently involved in this type of scientific activity as they should be. Enough to say that human (overt and covert) behavior is at the center of concerns regarding human biomonitoring, among other areas of environmental health. Beliefs and attitudes regarding exposure to environmental contaminants, human biomonitoring health communication, community-based biomonitoring screening programs (Uhl et al., 2021), are just a few examples of areas of research and/or applied knowledge requiring the intervention of psychology thought.

To better understand the development and current convergence of health and environmental psychological fields, it is worthwhile to think about the history of environmental health. The main goals of environmental health research usually tackle the fields of “disease prevention,” “protection against environmental hazards,” or “health and well-being promotion”. It is a field of research mainly dedicated to the study of the effects on human health of the short- or long-term exposure to chemical, biological or physical factors in soil, water and air. These efforts are typically oriented by the definition of recommendations on how to reduce human exposure to pathogenic environmental factors. It is not surprising that the main approach within environmental health has been the one of human biomonitoring, which constitutes an area of huge investment (see, e.g., HBM4EU, 2020). More vulnerable sub-groups of the population, such as children, pregnant women, and the elderly, are important populational target of environmental health research and intervention programs.

Although exposure-related behaviors are taken into account in environmental health studies, the fact is that researchers who are working in this area typically follow (a) a rather unidirectional perspective, from the environment to human health, not from human behavior to environment, and (b) a narrow perspective of what is the environment (mainly considered in its physical, chemical and biological facets). Santos et al. (2019) proposed a much broader perspective of environmental health, in which other environmental dimensions need to be considered, such as psychosocial environments (including schools, workplaces, communities, cultures, etc.), economic and political environments, and constructed environments, namely urban contexts and digital worlds. All these environmental “layers” have relevant interactive implications for both human health and sustainability of natural resources. According to this perspective, environmental health needs to complement the most traditional environmental focus on toxic-related factors with psychosocial, economic, political, and digital (mainly, Internet-based) factors, in order to explain the effects of the environment on human health as well as the effects of human longevity and well-being gains on the environment.

Environmental health is also an interesting multidisciplinary field in terms of its object of study and areas of intervention; it clearly assumes a biomedical perspective of health, mostly centered on toxic agents with corresponding human physiological dysfunctions. However, environmental health needs to endorse a biopsychosocial paradigm, considering social and psychological (cognitive, emotional, behavioral) pathogenic agents and parameters (Engel, 1977; Santos et al., 2019). This is an open debate because human health conditions and diseases are mostly determined by human behavior, also accounting for a big share of mortality, mainly in the developed world (Davis et al., 2015). Ultimately, this biopsychosocial-based endeavor of environmental health is paramount to ensure a planetary health view (Whitmee et al., 2015b), acknowledging the complex links between human health and the health of the Earth. This planetary health perspective has theoretical roots in both epidemiological methods and public health theories, focusing on emerging threats to natural and human-made systems that support humanity, within a long-term and sustainable perspective. There is, however, a lack of an integrated reflection on how psychological science can make a relevant contribution within this paradigm of planetary health. Again, health psychology and environmental psychology can assume a relevant role, at this level. Mainly, if combining efforts.

A clear example of environmental health and environmental psychology interconnection is the one of Ocean Health. Blue health expresses the bidirectional association of human activities and health, and the health of oceans. Fleming et al. (2019) highlight the fact that the health of the Global Ocean (including all ecosystems involved) is being seriously damaged by human activity. The massive use of non-renewable and renewable marine resources, associated with continuous discharge of waste materials, including industrial and agricultural chemicals, plastics, and pharmaceutical products, have a tremendously deleterious effect on oceans’ health. So, a lot needs to be done in terms of environmental behavior so that this global resource keeps being sustainable. This implies the building up of individual and community habits oriented for long-term gains; a difficult task for human beings (Hall & Fong, 2007; Hofmann et al., 2008), especially considering that this (environmental-related) long-term goes much beyond human life scale. Looking the other way around, and equally aligned with the interests of environmental psychology, is the concept of Blue Gym. As summarized by Fleming et al. (2019), human direct interactions with seas and oceans can lead to increased physical activity and improved mental well-being. Spending more time outdoors, ensuring (adequate) exposure to the sun, engaging in high-energy water sports, and/or in moderate walks are among possible mechanisms of action for this blue-gym positive effects on human health. Different studies showed that living near the ocean and having a view of it is associated with a lower risk of mental health problems (even after adjusting for socioeconomic factors; Dempsey et al., 2018; Garrett et al., 2019). This is a perfect arena of interest for environmental psychologists, eventually endorsing a “Global Ocean and Human Health and Well-being” research and intervention collaborative initiative, as proposed by Fleming et al. (2019).

In line with the abovementioned concept of Blue Health lies the one of Green Exercise, in which also natural environments (forests, gardens, mountains, etc.) stand in the midst of the relationship between health and the individual. The evidence shows that the proximity to a park or the riverside creates the opportunity for exercising on a regular basis in contact with nature, also facilitating social interactions with other users of these spaces (Loureiro & Veloso, 2017), thus reducing stress, mental fatigue and symptoms of depression, improving self-esteem (Mitchell, 2013; White et al., 2016) and enhancing mood (Barton et al., 2009; Kerr et al., 2012; Wells & Rollings, 2012). Exercising in contact with nature is an excellent opportunity for promoting health gains in a bidirectional fashion, also at the ecosystems’ level. Indeed, it is possible to contribute to environmental sustainability while exercising and reducing sedentary behaviors as a few programs have shown (World Health Organization, 2018).

Another area of concern for psychologists in general but where both health psychology and environmental psychology have major roles is, obviously, the psychological impact of environmental changes (most particularly, of climate change and global warming). These effects are pervasive, though not always obvious, and can lead to significant disturbance both at the individual (shock, sense of helplessness, posttraumatic stress, and increased levels of aggression, anxiety, depression, or substance abuse) and at the social (relationships are put under pressure) levels (Sawitri et al., 2015). Also, evidence shows that air pollution (namely due to particulate matter; PM_2.5) is associated with a higher risk of depression, and potentially, with anxiety (Braithwaite et al., 2019).

The relevance of the contribution of psychology for mitigation, adaptation, and activism actions regarding climatic change was fully acknowledged in the 2019 international summit on psychology and global health, organized by the Ordem dos Psicólogos Portugueses (i.e., the Portuguese Psychological Association) and by the American Psychological Association, resulting on a resolution text that was signed by more than 40 psychological associations, positioning psychology science as an “a leader in climate action” (PsyGlobalHealth, 2019).

Health and Environmental-Friendly Behaviors: Common Grounds for an Environmental Health Psychology Discipline

There is a main challenge common to health psychologists, environmental psychologists, and those involved in the overarching field of environmental health: how to promote the adoption of adequate habits? When looking for creating positive impacts on human health (both physical and psychological), as well as on planetary health, individuals need to activate and, more importantly, to maintain behaviors that are considered to be effective for health promotion and well-being; ultimately, for life sustainability and longevity. Unfortunately, such behaviors (e.g., physical activity, eating healthy and adequate amounts of food, recycling, commuting by foot or with bikes, etc.) compete against alternative behaviors that are more intrinsically rewarding (eating fat and sweet food, driving a sportive car, etc.).

Planning in the long-term is not an easy task for humankind. We can think about humans as “immediate gratification-prompted animals”. The seminal work of Hall and Fong provided inspiring evidence about the effect of the relative moment of onset of obstacles and gains associated with health behaviors (Hall & Fong, 2007). These authors showed that because aversive factors associated with physical activity (e.g., body pain) are expected to emerge much before the gains of physical activity (e.g., reducing weight or feeling athletic), there is much fewer chances to engage and maintain this behavior; changing the focus of attention to immediate gains and delayed discomfort may be a good way to overcome this effect (Hall & Fong, 2007). The field of economic behavior science also mapped different cognitive intertemporal choices phenomena, such as hyperbolic time discounting (Ainslie, 1975) and intertemporal distribution of costs and benefits (Akerlof, 2016), all of them supporting the daily empirical evidence that human motivation tends to be more oriented to behaviors associated with perceived immediate gains. This is obvious for intrinsic motivation in which the behavior itself is rewarding (e.g., eating a chocolate mousse); but it is also true for extrinsic motivations in which the reward is obtained in time-contingency, the main factor of all learning theories (Deci & Ryan, 1987; Skinner, 1965). Environmental psychologists have done extensive work around the construal-level theory of psychological distance (Trope & Liberman, 2010; Wu et al., 2014). According to this construct, the more distant is the object of thought from direct experience, the more abstract and distant is the representation of the object and the less relevant it becomes from a phenomenological perspective of the person. This is completely in line with the empirical observation that the concept of chronic disease in older ages has few impacts on health behavior related decisions for adolescents, and it may also explain why thinking about far away climatic changes (in both time and space) is a weak prompt for environmental protective behavior. Denial and several other cognitive biases have been suggested as mediators of the decision making when psychological distance or inter-temporal choices push the individual in the direction of the non-health, non-pro-environmental choice (Kahneman, 2011). This low effect of distant gains tends to favor a low perception of the efficacy of the (rather objectively) adequate behavior (e.g., recycling).

On the other hand, perception of effective behaviors is a key determinant of decision making in social learning theory (Bandura & Walters, 1977): if someone believes that a specific behavior leads to the desired outcome, the possibility to engage in such behavior will increase. Another key mediating variable for the decision making is individuals’ self-efficacy (Bandura, 1982): individuals with higher perceived self-efficacy tend to be more easily activated for the behavior, namely also on climate-related behaviors (Sawitri et al., 2015). Interesting to note that whereas psychological distance is a concept more easily found in environmental psychology research, delayed versus immediate rewards are more frequently used as explanatory variables in the area of health psychology. There is, again, a large avenue for studying the combined interpretative value of these constructs.

Another interesting line of research to pursue would be the study of adequate communication (promoting environmental health literacy) of behaviors that have a synergic effect: being positive for human health and for planetary health. Good examples of such behaviors are (Cunsolo et al., 2018): reducing red meat consumption, adopting active commuting, public transportation, investing in creating and/or visiting green spaces, investing in clean energy. These behaviors are environmental-friendly and have positive psychological effects on stress, anxiety, and other mental illnesses; moreover, as stated by Cunsolo et al. (2018) they contribute to fighting against the decline of social identity that comes from climate damage (a major topic in environmental health research, in itself).

Final Remarks

Homo sapiens is far from being an old species; we are very far even from being the longest living species among our homo genus “relatives” (homo erectus lived for almost two million years; Harari, 2014). The impact of the human worldwide community on natural ecosystems is clearly associated with current serious threats to our existence. Recently, a large group of scientists published a well-founded paper to highlight the responsibility of mankind on climate change and alerting for the imperative of taking concrete and critical actions in order to avoid imminent disruptions of ecosystems current balance, supporting human life (Venhoeven et al., 2016). Ultimately, values, motivations, beliefs, attitudes, decision makings, behaviors, and habits, at individual, familial, and community (at local, national, and international) levels, will play the fundamental role of promoting planetary health and, within it, human health. Psychological science has a long and rich evidence-based descriptive and explanatory set of theories about human behavior (Armitage & Conner, 2000; Davis et al., 2015; Kwasnicka et al., 2016; O’Cathain et al., 2019). However, we are still far from having robust predictive models for maintained health and pro-environmental behaviors (at individual and at group levels). More than ever, we need to integrate cross-disciplinary knowledge and efforts in this direction. Health psychology and environmental psychology are natural candidates for the overall effort of understanding and improving environmental health. An integrated environmental health psychology discipline seems a logical step forward. This is especially relevant when we realize that so many health behaviors are synergic with pro-environmental behaviors (Bains & Turnbull, 2019; Cunsolo et al., 2018; Swinburn et al., 2019). It also makes sense when thinking about the footprint of healthcare units and activities (Sherman et al., 2019). Both examples (among many others) demand a joint theoretical and methodological action from health and environmental disciplines.

In 2007, Cheng et al. (2007) alerted to the possibility of re-emergence of severe acute respiratory syndrome (SARS) coronavirus – or a mutation of that virus; at that moment, the authors considered this as a near inevitability. In their own words, “The presence of a large reservoir of SARS-CoV-like viruses in horseshoe bats, together with the culture of eating exotic mammals in southern China, is a time bomb” (Cheng et al., 2007, p. 683). First climate models with good capacity to provide accurate forecasts of subsequently verified global surface warming date from 1970 (Kay, 2020). These facts make it very clear that data and information are not enough to activate individual nor communities to modify habits and lifestyles. We need better and sound models for the promotion of long-during salutogenic habits. We believe that this can only be achieved, in long-term, if social norms and individual values are oriented to the activation of adequate (i.e., healthy, for individuals and planet) behavioral choices. Such values, together with capability assets (De Matos et al., 2019), will inform autonomous motivation for enkratic choices and behaviors: choices that may lead humanity to a brighter future.