Nature, Cities, Health, and Healing
May 2024
“We [Indigenous Peoples] are taught under the city there is Nature…..it is in the plants, birds, us as people”
wise words from Angela Camacho, a 20 year resident of Elephant & Castle, London and a person of Indigenous Quechua descent. These words are shared by astrophysicist Carl Sagan:
“The nitrogen in our DNA, the calcium in our teeth, the carbon in our apple pies, were made in the interiors of collapsing stars, we are made of stardust.”
We are intrinsically linked to our environment and its biodiversity. From our ability to develop strong muscular-skeletal systems as children to the microorganisms influencing our gut bacteria that regulate immune functions, we are Nature. As ecologist Jake Robinson highlights in this report:
‘the gut microbiome is the densest microbial habitat in the human body, with trillions of bacteria, viruses, fungi, and others calling it their home. The genes in our microbiome outnumber our own ‘human’ genes by 150 to 1, and if we could extract the microbes from a single person’s gut and line them up, they could circle the Earth 2.5 times.’
We are Nature, it defines us, it has created us, and we must refind this connection for a healthier and more sustainable future. As the changing climate proposes new challenges we must understand how to return to working as part of Nature, not using it for our own advantage.
However, the challenge for space in cities has meant a compromise on our access. Data published by the Greater London Authority shows that 62% of Londoners don’t have access to a local park and 74% to a regional park. These statistics become more troubling when the NHS prescribes visiting and spending time in Nature as a form of healthcare. This recent change is undoubtedly inspired by the Japanese practice of Shinrin-yoku, or forest bathing, which has been prescribed by doctors in Japan since the 1980s as a method to combat the challenges of modern urban life. It is not something unique to Japan, many societies practice connecting with Nature; the Maori people in North Island’s Waipoua Forest invite people to walk with their ancestors and be in the presence of trees that are estimated to be between 2,500 and 3,000 years old, such as Te Matua Ngahere ('The Father of the Forest').
Meeting the challenge of low access and poor health outcomes is not just a spatial issue, it is also an issue of social connectedness. This report highlights the cultural and practical changes needed to protect Nature in cities and embrace the existing relationships and knowledges. This report provides its readers a new lens in looking at Nature by investigating the different epistemologies, ways of understanding, of health, nature, and community.
Understanding Nature
When we speak about Nature it is important that we create a common understanding and seek to open ourselves up to a wide range of meanings and perspectives. In the first place, we are going to move away from European epistemology which has contributed to the distance we can sometimes feel with Nature.
Epistemology refers to the root of knowledge which in turn shapes the way we think and perceive the world. Anthropologist Clifford Gaertz says “man cannot confront reality immediately, he treats physical reality only through the symbolic construction of language, myth, heart, magic and science.” (source). Meaning we create our realities through various mental constructions, including language.
Many European languages refer to Nature in terms of a “what” or an “it”, suggesting that Nature is not alive, or a being. This, in turn, roots Nature as a “thing” and separates humans, who are “beings”, from Nature. This has had an influence on how Nature is perceived by many European or industrialised cultures.
Perceiving Nature as a “thing” and separate from us creates a cultural perception that Nature can be owned, destroyed, changed, sold, consumed, or contaminated without a sense of responsibility or reciprocity. These perceptions help paint our current reality which finds the places that we live polluted, lacking biodiversity, and in biological chaos.
However, not all cultures perceive Nature in this way. For example, the Inca view Nature as an interconnected, interrelated, cosmic whole. Humans are Nature and there is no separation between land, water, air, mountains, insects, the cosmos, or us. This way of framing reality creates a bond between all of us that is unbroken, we are all Kin.
Professor Robin Kimmerer, a Patwamatomi professor from Turtle Island, has spoken about using a different language to refer to Nature: not as an “it” but as Kin. We go one step further by capitalising the word “Nature” as we have been doing throughout this paper. This is to denote the importance or significance of Nature.
We also use “they” to refer to Nature, as Nature is plural. Using “they” also removes the pronouns that could take away the beingness of Nature. Variations of this point of view are shared by different Indigenous communities all over the world which have influenced a wide range of stewardship practises and scholarships that honour our relationship with Nature. This is also reflected in the fact that most of the biodiversity today is found in areas inhabited by Indigenous peoples.
Taking all this into consideration, we propose the following working definition of “Nature”:
Nature encompasses the time and space for all living beings to exist. They hold an active energy that runs through all of us from the cosmos, to cells, to mountains, to rivers, to people, and they have a communal wisdom that holds healing, sustenance, and growth. In this view, all beings are connected, and we are Kin deserving of healing and dignity.
There are many different factors that contribute to how a society, culture, or person defines and understands who Nature are. For instance, how we view ourselves (humans) in relation to (the rest of) them. Are we only surrounded by Nature, or are we also part of them? If we are part of it, what is our role in Nature? Our connectedness to and perception of Nature have evolved along with our societies, and they differ considerably between individuals, communities, nations, and cultures. Some peoples view Nature as a densely tangled web of interrelated subjects (including human, plant, non-human animal, and microbial subjects) and not as a collection of discrete objects.
It is important that we acknowledge that all of us will have different definitions of Nature; we are not looking for universality. Instead, we are looking for pathways to rebuild our relationship with Nature.
From our collective experiences as individuals and scientists from various cultures, we have identified a core pathway, which is building a Kinship with Nature.
By Kinship we mean a deep relationship, one that resembles or is akin to the relationship we have with our family and friends. Professor Wall-Kimmerer says that this Kinship starts with knowing Nature, for example, by learning their names, what they need to live, and what their gift is to the planet.
A great example is a primary school project in Iceland where children were asked to identify, name, and draw the different birds they saw on the way to school. By the end of the project they were able to name over 20 different types of birds and expressed that they enjoyed being outdoors more than before the start of the project.
An important factor of Kinship is reciprocity which means that we gift to Nature; take care of a plant, or restore a bee colony. In order to live in Kinship with Nature, we must radically change our minds about Nature. This requires new words and new knowledge roots.
For this we suggest living in mutualistic symbiosis with Nature, which requires us to not just gift back to Nature but to know them, take only what we need (causing little to no harm), learn the ecosystemic needs of Nature, see ourselves as being with rather than in Nature, see the wisdom of Nature, and learn how each part of our life interacts with our wider ecosystem.
“The microbes that live in our bodies are supplemented by the microbes in the environment and the microbes in our foods. Humans emit a million biological particles every hour, including a considerable portion of microbes. We each have our own signature microbial clouds that follow us around. There are approximately a million microbial cells in a single cubic metre of air, and people can inhale a whopping 100 million bacteria each day. In essence, the microbes in and on our bodies and the microbes in the environment are constantly being exchanged.”
Understanding Healing
The origin of the English word “Healing” comes from the Old English word “haelen” which means “to make whole”. Here, “whole” means a state that is complete, unbroken, or uninterrupted. Additionally, “healing” is in a verb format which, meaning it is an action, which requires a process. Therefore, the first part of a working definition for “Healing” is that it is “a continuous and uninterrupted process that sustains wholeness”.
It is important to note that ‘healing’ is not static but dynamic: as we move through life wholeness also moves, evolves, and changes. It also moves with the injuries or traumas we face. For example, if we experience an accident, we move towards another state of wholeness rather than moving back to our original state. We also recognise that it is not about reaching a state of perfection, which is not possible or ethical. All of us will find our own feelings and states of wholeness depending on our culture, life, experience, and growth. Therefore, it can encompass a variety of elements. For example, in a study looking to find the meaning of healing, respondents “described wholeness of personhood as involving physical, emotional, intellectual, social, and spiritual aspects of human experience”.
Elephant & Castle (London) resident Angela Camacho sees that
“healing is complex and can come in many ways…. Even a market or building can provide healing”.
With this we see the importance of physical infrastructure as a pathway to healing.
The Biological Mechanics of Healing
Neuroscience is the study of the nervous system which expands from the brain to the spinal cord. As a result, neuroscience is able to observe how our biological systems interact with each other and with the places we live, and therefore help us understand the different parts of the healing process.
The healing process can involve two pathways: restorative and adaptive.
From an adaptive perspective, our body uses various systems, such as the hypothalamic-pituitary-adrenal axis (HPA-Axis) to observe changes in the environment in order to make adaptive changes within our bodies. For example, during a heatwave, our body will sense the change in temperature and through the communication between HPA-Axis, respiratory, and cardiovascular systems our body will go through a wide range of changes to adapt to the heat: we change our breathing rhythm, our heart starts to pump faster to move oxygen through all of our tissues, and, of course, we start to sweat to begin the cooling process.
The body also has a great ability to constantly restore, aiding the healing process. Each and every time, we take a deep breath, through practises like meditation, yoga, or walking, our vagus nerve engages. The vagus nerve is long, running from the brain to the colon, meaning it's involved in the function of immune, endocrine, digestive, and cardiovascular systems. It is significant that we can engage it so easily and constantly as it creates an anti-inflammatory response, which helps restore vital organ function and lower the risk of disease. Both through adaptation and restorative processes, we are able to come back to a whole on a daily and constant basis.
There is a final factor to consider and that is the role that rich biodiversity plays in our healing. In the example of taking a deep breath, we are inhaling oxygen, which needs to be nourishing in order to sustain the process of healing. Nourishing air is generated by trees, fungi, microbiome, vegetation, wind, and water working together. In the further sections, we will highlight all the various ways in which our healing is linked to biodiversity. Our healing process is directly linked to the healing process of our planetary systems; therefore, returning to a whole is not just about us, it is about the entire planet.
Therefore the second part to a definition of healing is that “the process is entwined with the world around us.”
Understanding Biodiversity
Biodiversity refers to the variety of life on Earth, from genes and traits to species and ecosystems. The term was popularised in the mid-1980s by the late evolutionary biologist E. O. Wilson who eloquently penned the term in his 1998 book Biodiversity.
Early ideas about the variety of life on Earth were summarised by the International Union for the Conservation of Nature. The IUCN suggested biodiversity provides both “insurance” and “investment” benefits. The focus on the importance of the variety of life for ecosystems and human health and well-being was echoed later in the Convention on Biological Diversity’s definition of “biodiversity”, and more recently in the Intergovernmental Platform on Biodiversity and Ecosystem Services.
To some people, biodiversity holds value in itself and for itself––this is also known as intrinsic value. This philosophical view positions all organisms, including microbes, as having a value and right to exist irrespective of whether they are instrumental (useful) to humans and their endeavours. The contrasting view of intrinsic value is that biodiversity has instrumental value, shown by its direct relationship to our wellbeing and survival, such as through foods, medicines, and nutrients.
A whopping 1 trillion microbial species exist on this planet as part of the biodiversity ecosystem, 125,000 times the number of species, animals and plants (8 million). Unfortunately, without transformative interventions into our treatment of Nature and the planet this number that we rely on is going to decrease, putting our human sustainability at risk.
The book Braiding Sweetgrass by Professor Robin Wall-Kimmerer, which is a study on Turtle Island Indigenous Land cultures, highlights that in some languages (Native) the word for “plants” translates to English as “those who take care of us”. In order for plants to have the ability to take care of us, they would need to be seen as sentient and intelligent with the ability to hold and pass on their own wisdoms. Therefore, when we lose biodiversity, we are losing those who take care of us and their wisdoms that keep our planet in equilibrium.
Nature in Cities and Healing
In previous sections, healing was described as “a continuous and uninterrupted process that sustains wholeness.” We also wrote about Nature being a crucial part to sustaining “wholeness”. In this section, we will be exploring the various ways in which Nature helps us move towards our wholeness.
To start with, we need to create a baseline for what it means to have Nature in an urban environment. The first place to start is differentiating between Nature and a natural environment. Many interpretations of what constitutes a natural environment exist. Some people consider a meticulously designed and curated garden or urban park to be natural, as it may include some green space (e.g., trees) or blue space (e.g., a pond), and may be home to animals (e.g., birds) and other organisms (e.g., microbes).
Some people would only consider environments with low to no human impact to be natural (as they have evolved ‘naturally’). Some people would say that all environments are natural, including those shaped considerably by humans, as humans are constituents of the natural world. Therefore, anything created by humans must also be natural. Arguably, all these different perspectives are valid. For an urban context, we are proposing the following working definition for a “natural environment”: a time and space where clusters of Nature are held in their own autonomy to create healing, regeneration, and sustenance.
Using the current scientific knowledge, it is possible to identify several mechanisms that underlie the link between Nature and health. Mechanisms describe the causal relationship between a stimulus/exposure (i.e., a component of Nature) and the health-related response/outcome (e.g., the regulation of the immune system). In other words, mechanisms describe how the exposure (Nature) affects the outcome (health). The mechanisms underlying the link between Nature and healing are categorised into six broad pathways. For each pathway, there would be several examples of mechanisms underlying the Nature-healing relationship.
The following pathways are written in a linear format to create clarity, however they often work in tandem and even simultaneously. For example, a person going for a run will be exposed to exercise, social interaction, immune regulation, spirituality, and, consequently, will experience the healing outputs in a systemic and simultaneous manner as well.
Biological (e.g., the pathway to immune regulation)
Psychological (e.g., the pathway to reducing stress and anxiety)
Social (e.g., the pathway to promoting community cohesion)
Physical activity (e.g., the pathway to facilitating exercise and associated cardiovascular benefits)
Spiritual (e.g., the pathway to enhancing spiritual well-being)
Environmental buffering (e.g., the pathway to reducing pollution and the associated respiratory benefits)
It’s important to note that allowing people to achieve these goals means addressing some of the historical injustices that have seen people removed from a connection with Nature; Displacement, time constraints driven by economic inequities, racism, ableism, and classism all contribute to a disconnection. Addressing these factors is crucial to enabling healing through Nature in urban environments.
Invisible Nature: The Microbiome & Healing
A primer. For more on the microbiome please go here.
The microbiome can be defined as the entire collection of microbes (bacteria, algae, archaea, fungi, protozoa, and viruses) in a given environment, and its ecological theatre of activity. In the scientific realm, we tend to separate the microbiome into the environmental microbiome and the human (or animal) microbiome; but, really, both interact with each other in a constant flux of activity.
What is the environmental microbiome?
The environmental microbiome refers to the microbial communities that reside in the soil, the water, the plants, and the air (also known as the ‘aerobiome’). In terms of diversity, the soil is one of the densest habitats on Earth. A single teaspoon of soil would likely contain between 10,000 and 50,000 different microbial species. There are approximately one trillion different microbial species in our planet’s natural environments. This is ten times as many species as there are stars in the Milky Way. Each environment has its own unique microbiome. The environmental microbes play vital roles in the functioning of our ecosystems.
What is the human microbiome?
The human microbiome is the collection of microbial species that live in and on our bodies. Each body site has its own unique microbial community. For example, the microbiome of our armpits is distinct from the microbiome of our mouths or guts. The gut microbiome is the densest microbial habitat in the human body, with trillions of bacteria, viruses, fungi, and others calling it their home. The genes in our microbiome outnumber our own ‘human’ genes by 150 to 1, and if we could extract the microbes from a single person’s gut and line them up, they could circle the Earth 2.5 times. The microbes in our bodies play essential roles in maintaining our health and ‘homeostasis’ by regulating our immune system, digesting our foods, and providing chemicals to keep our cells and organs in a healthy state.
How do the environmental and the human microbiome interact?
The microbes that live in our bodies are supplemented by the microbes in the environment and the microbes in our foods. There are approximately a million microbial cells in a single cubic metre of air, and people can inhale a whopping 100 million bacteria each day. In essence, the microbes in and on our bodies and the microbes in the environment are constantly being exchanged. Some environmental microbes are fleeting visitors, and some are long-term residents in our bodies.
Introduction to Microbiome Health & Human Health
The loss of microbial diversity associated with urban areas underpins the so-called “biodiversity hypothesis” which proposes a link between two global megatrends: 1) biodiversity loss and 2) a rapid increase in noncommunicable diseases (NCDs; e.g., diabetes, inflammatory bowel disease, and mental health problems). A growing number of studies support the biodiversity hypothesis. Evidence shows that the microbiomes associated with urban areas and urban lifestyles are suboptimal for health and well-being. The evidence spans different levels of empirical study, including human population-level studies, human cohort studies, and many animal model studies. Collectively, these studies support calls to conserve and restore biodiversity in our urban areas to enhance human health. This has the crucial co-benefit of supporting the other organisms who share the land with us.
The Importance of a healthy Microbiome in Cities
Interestingly, preliminary results also show that the relative abundance of pathogenic microbes (the few that can cause human diseases) significantly decreases when more trees and plants are present in the urban environment. All of this suggests that, if we increase the number of plant species and structural diversity (i.e., different shapes and sizes) in our urban areas, we will be exposed to a greater variety of beneficial microbes and to a reduced level of pathogens in the air.Therefore, ecological restoration can be viewed as a public health intervention. This means that bringing biodiversity into our cities is not only aesthetically pleasing and good for wildlife, but it is good for human health too.
The Climate Crisis & Biodiversity
The climate crisis is often understood through the big catastrophic moments, such as hurricanes, flooding, and snow storms. However, these catastrophic moments are only one part of the story. There is also the disruption to our ecosystems through contamination of soil, water, and air. This contamination is putting a lot of stress on the microbiome and, in turn, on biodiversity, and this stress is causing the rhythms of Nature to change and extinction.
Further, we are asking too much from Nature in terms of their adaptive capacities: Nature cannot be overburdened by contamination in the way that we are witnessing. As Zandalinas et al. (2021) said,
“Global warming, climate change, and industrial pollution could result in an increase in the frequency, complexity, and intensity of multifactorial stress combinations impacting plants, soils, and microbial communities”.
For this reason we need to expand our conversation about the climate crisis beyond the weather disasters we are experiencing and whether or not we can adapt to these disasters.
One of the key impacts of climate change on macro biodiversity (e.g., plants and animals) is the increased frequency and intensity of storms, fires, and periods of drought. As the Royal Society said,
“the threat posed by climate change to biodiversity is expected to increase, yet thriving ecosystems also have the capacity to help reduce the impacts of climate change.”
This is another reason for restoring our ecosystems, both rural and urban. Rising global temperatures have the potential to change ecosystems by altering the conditions for the residing organisms. Evidence suggests that changes in atmospheric water vapour due to climate change may be increasing plant stress across the planet. Climate change can also increase the spread of pathogens and so-called “invasive species” that can wreak havoc on the integrity of ecosystems.
Biodiversity is not just plants, it also includes the invisible organisms called microbes. Microbial biodiversity has a key role in climate regulation and is therefore important in the realm of climate change. Many microbes, including bacteria, algae, fungi, archaea, and viruses, play critical roles in nutrient cycling and climate regulation in both aquatic (water) and terrestrial (land) environments. Microbes living in the soil help to regulate the organic carbon stored in soil and the amount released back into the atmosphere. Soil microbes influence the carbon storage of plants by providing nutrients that regulate productivity. Therefore, microbes have a role in carbon storage. However, they also have a role in carbon release.
Plants remove carbon dioxide from the atmosphere through photosynthesis and create organic matter that is decomposed by microbes, whereby carbon dioxide is released. These opposing processes are primarily responsible for climate regulation. Unfortunately, climate change is expected to accelerate the release of carbon dioxide into the atmosphere by promoting higher rates of decomposing organic matter.
Marine microscopic phytoplankton are responsible for 50% of the global photosynthetic carbon dioxide fixation and oxygen production. Amazingly, phytoplankton only comprise around 1% of global biomass, so this is an incredible feat. It is thought that climate change could soon diminish phytoplankton biomass, thereby reducing global carbon dioxide uptake. This could potentially exacerbate climate change. So, enhancing both green (land and vegetation) and blue (aquatic) spaces is imperative.
The Future is in the Soil
It might at times feel like the future is bleak or we might feel overwhelmed by the enormity of our challenge. Here are two pieces of insight to consider. The first is that Nature has their wisdoms and timeframes that are far more sophisticated than our minds can comprehend; therefore, our only role is to stop their exploitation and contamination. This gives Nature the opportunity to find their own path to healing.
The second insight is to focus on the soil. The Quechua doctor, midwife, and scholar Dr. Vivian Camacho says that “there is no future without the soil”. This means that if we learn to collaborate with Nature by aiding in the restoration of the soil’s microbiome, we create the time and space that Nature needs to heal. Once the nourishment of the soil is restored it paves the way for every element of biodiversity to grow--from fungi, to tree, to river, to mountain, to us.
“The soil is the great connector of lives, the source and destination of all. It is the healer and restorer and resurrection, by which disease passes into health, age into youth, death into life. Without proper care for it we can have no community, because without proper care for it we can have no life”
- Wendell Berry / Poet & Environmental Activist
People, Nature & Health
Each and every one of us needs Nature to survive and to thrive, but there are great inter-individual differences in what exactly we need from Nature and, therefore, what type, form, or composition of Nature we need.
Some people may benefit more from the restoring qualities of Nature (e.g., stress reduction), whereas others may benefit more from the instoring qualities of Nature (e.g., physical activity promotion). The former may need a ‘wild’ natural environment, whereas the latter may need a space with a little more maintenance (e.g., paths for running).
Our needs, of course, are not static but change constantly. They depend on all the other experiences we make during a day or week (or, indeed, month, year, or decade). Such inter- and intra-individual differences in needs suggest that cities must provide a range of natural environments with different characteristics.
Every neighbourhood should provide several, diverse opportunities for engagement with Nature.
Children
When we are children, our entire bodies and systems are in development. Significantly, we develop directly in relation with the environments we live in. For instance, our sensory motor cortex (SMC), which helps with mobility (source), forms with the textures, elevations, and endurances of the environments we walk or crawl on. It is important for cities to create “managed areas in an existing or modified outdoor environment where children of all ages and abilities play and learn by engaging with and manipulating diverse natural elements, materials, organisms, and habitats, through sensory, fine motor and gross motor experiences.” (source)
Our immune systems also form alongside Nature; they are dependent on external sensory inputs during their development. In particular, we need exposure to environmental microbes found in Nature (source). Exposure to many different types of microbial life, particularly in childhood, is considered a good thing because it allows our immune systems to build up a strong army of memory cells that protect us from pathogens. This is known as our adaptive immune system. Further, certain microbes known as ‘old friends’ are thought to have an important regulatory effect on our innate immune system. Without this regulatory role, our immune systems attack innocuous particles, such as dust and pollen (i.e., allergies), and sometimes even our own cells; this is known as ‘autoimmunity’. Enhancing urban biodiversity, such as diverse plant communities with quality soils, can enhance the microbial diversity of the local environment.
Adults
There are two theories that address the positive impact of Nature on mental health: the attention restoration theory (ART) and the stress recovery theory (SRT). Both were developed in the 1980s and 1990s, and, since then, much evidence has accumulated that supports the idea that exposure to Nature does indeed restore/recover our cognitive and affective capacities (source/source). It’s worth noting that while physical exercise in general is associated with better physical health, ‘green’ physical exercise may be even more beneficial.
Several individual factors, such as sex, age, and health, affect what the individual needs to be able to access and to benefit from Nature. In addition, it is important to remember that factors of an individual’s everyday physical and social environments influence what the individual needs most from Nature. A person spending much of their time sedentary in an office environment with little air and noise pollution, may benefit most from restoration and physical activity. A construction worker who is physically active but exposed to air, noise, and heat pollution throughout the day, may benefit most from the quiet and the clean air.
Older People
The second important state is when we reach old age. Due to various complex factors, such as exposure to air pollution, poor access to Nature, poor quality sleep, and trauma, dementia is increasing amongst older people. Therefore, we have to take this into consideration when planning with Nature in urban settings. Exposure to Nature and natural environments has proven to play a role in slowing the progression of the disease (source). Nature can also keep elderly mobile as they can go for walks, meet people, or do other light activities, such as gardening. Nature should be part of our entire life cycle from childbirth to old age.
If we want to achieve equitable engagement with Nature, we must consider the many different perspectives, interests, and needs of people. We must also move away from looking at single natural spaces independently; rather, we must see the whole network of natural spaces and elements in our cities (including their connections). The question must be: does this network offer sufficient (safe, regular, and high-quality) opportunities for all people to engage with and benefit from the healing qualities of Nature?