The scientific definition of sound, which is omnipresent throughout the world, is “a vibration that propagates as an audible wave of pressure, through a transmission medium such as a gas, liquid or solid,” and each sound is characterized by its wavelength hertz (Hz), intensity (decibel), speed, and direction. The audible sound that is perceptible by humans has frequencies from about 20 to 20,000 Hz.

The simplest definition of silence is the absence of human noise. Silence, then, is all the sounds from the Earth minus anthropophony, noise produced by humans. According to acoustic ecologist Gordon Hempton, who has been recording sounds from the Earth for the past 40 years, silence is on the verge of extinction. He believes there are at the most 50 areas around the world which can be called silent. The bioacoustician Jérôme Sueur has written a natural history of silence (Actes Sud publisher) in which he examines all the different kinds of silence.

Biophony, a term coined by Bernie Krause, is the study of sounds coming from plants and animals. It explores new definitions of animal territory. It addresses changes in diversity, density and richness of the animal population.

Also called ecoacoustics or soundscape, is a discipline studying the relationship, mediated through sound, between humans and their environment. Acoustic ecology can inform us of changes in the climate or other environmental changes since every day we listen to sounds in the world to identify their source such as bird, car, plane, wind, water. But we don't listen to those sounds as a network, a mesh of relationships that form an ecology. A soundscape is a combination of biophony, geophony, and anthrophony. Across time and space, various combinations generate unique soundscapes.

It is the study of the Earth’s sounds, like the wind blowing, thunder, rain or waves crashing, for example.

A growing body of research shows that chronic noise is not just annoying, but a threat to the health, increasing the risk of hypertension, stroke, heart attack, according to a story published in the New York Times. Noise exposure primes the body to overreact, amplifying the negative effects. Noise enters the body through the ears, but it is relayed to the stress detection center of the brain called amygdala. If it is chronically overactivated, it starts to produce harmful effects. Researchers in Boston made an astounding discovery: People who lived in areas with his levels of transportation noise were more likely to have highly activated amygdalia and within five years major cardiac events.

Until recently, the emphasis has been on preserving the Earth’s biodiversity and the habitats these organisms depend upon. However, soundscape ecology encourages biologists to consider natural soundscapes as resources worthy of conservation efforts. Soundscapes that come from relatively untrammeled habitats have value for wildlife as demonstrated by the numerous negative effects of anthropogenic noise on various species. Organisms that use acoustic cues generated by their prey may be particularly impacted by human-altered soundscapes. In addition, natural soundscapes can have benefits for human wellbeing and may help generate a distinct sense of place, connecting people to the environment and providing unique aesthetic experiences.

Noise is a byproduct of increased urbanization. The volume and frequency of anthropophony has increased. Animal biodiversity has shown to decline because of chronic noise levels in cities and along roadways. Birds may be particularly sensitive to noise pollution given that they rely heavily on acoustic signals for intraspecific communication. The great tits, for instance, have changed the frequency of their call to adapt. One study focusing on community composition found that habitats exposed to anthropophony hosted fewer bird species than regions without noise, even though both areas had similar numbers of nests. Beluga whales have been observed to raise their voices (like humans in a crowded pub) when there is loud shipping noise.

A whole symphony of sounds, sights, scents, and sensations surround us, and we blindly walk right through them. Cymatics is the science of sound and vibration made visible. In the most common mode of operation, a surface such as a large plate or a diaphragm is peppered with a thin layer of particles, paste or a liquid. A particular frequency is then passed through the surface and the particles begin to take on marvelous geometrical patterns which correspond to the frequency applied. Each frequency creates a different image. The musical notes are brought to sight. The patterns that emerge from the sounds are analogous to the patterns that are created in sacred geometry.

According to French philosopher and psychotherapist Cynthia Fleury, who has co-authored a pamphlet called Ce Qui Ne Peut Être Volé (What cannot be stolen), “silence is one of the key factors contributing to the well-being, an essential element to mental and physical health, according to researchers in environmental psychology or 'geography of health'. According to Fleury, silence has four functions: Spiritual (in silence we can access the sacred), intellectual (without silent focus one cannot think , invent, etc.). The third function is therapeutic (silence preserves our physical and psychic health), and, finally, silence is necessary for a healthy public life (to have any kind of civic life, one needs to be able to listen to others, therefore to be silent). "These 4 functions of silence make it an indispensable individual and collective resource for the health of a democratic life,” she claims. For the philosopher, the creation of private and public spaces, architectures, services, neighborhoods, public transportation which allow everyone “to have free and durable access to silence is to preserve the quality of our attention to the world, to ourselves and to others, humans and non humans.” Cynthia Fleury & Antoine Fenoglio, Ce Qui Ne Peut être Volé (Tracts Gallimard).

Fog is a low-lying cloud and its moisture is generally locally generated. Fog appears when water vapor condenses into tiny droplets that are suspended in the air. It is highly influenced by nearby bodies of water, wind and topography. According to the generally accepted definition, fog reduces visibility to less than one kilometer. Giants redwoods, the biggest and oldest trees on the planet, receive almost 40% of their moisture from coastal fog through fog drip. Insects depend on wet fog as their principal source of water.
The disappearance of fog would

In particularly dry regions where rain is rare or non-existent, like along the Peruvian coastal region, in Mexico, Bolivia, Colombia, people have been trying to catch - to harvest - water from fog using mesh strung up on hillsides. Tiny droplets condense on the netting and dribble down into pipes that carry the water into containers where it can be used to irrigate crops or even as drinking water. Each net can capture between 200 and 400 liters of fresh water per day. More technologies are being developed. For instance, two Chilean architects are developing fog harvesting towers to collect water as high as possible in the fog.

Cloud forests or water forests are generally tropical or subtropical moist forests characterized by a frequent, persistent or seasonal low-level cloud cover, usually at the canopy level. Cloud forests are amongst the most biodiversity rich ecosystems, with a large number of species directly or indirectly depending on them. Only 1% of the woodland consists of cloud forests. In the 1970’s they comprised over 11% of all tropical forests. A total of 736 cloud forests have been identified in 59 countries by the UN’s World Conservation Monitoring Center. Half of these cloud forests are located in Latin America. Because of their dependency on local climate, these forests are affected by climate change. It would greatly impact species living in those areas like frogs and lizards, for example and cause the extinction of species.

At any given moment, about two-thirds of our planet is covered by clouds. So it’s not too surprising that clouds play an important role in Earth’s climate. They affect climate in two major ways. First, they are an essential part of the water cycle. Clouds provide an important link between the rain and snow, oceans and lakes, and plants and animals. Secondly, clouds also have an important effect on Earth’s temperature. Clouds can both cool down and warm up the temperatures on Earth. Clouds within a mile or so of Earth’s surface tend to cool more than they warm. These low, thicker clouds mostly reflect the Sun’s heat. This cools Earth’s surface. Clouds high up in the atmosphere have the opposite effect: They tend to warm Earth more than they cool. High, thin clouds trap some of the Sun’s heat. This warms Earth’s surface. Climate scientists predict that as Earth’s climate warms, there will also be fewer clouds to cool it down. So, unfortunately, we can’t count on clouds alone to slow down the warming.

Flying rivers are moisture-laden air currents - aerial rivers - formed above the Amazonian rainforest and extend over a large part of the South American continent. Flying rivers are created by the water vapor released by the billions of trees in the Amazon forest. On average, a forest tree releases 1,000 liters of water vapor into the atmosphere every day - 8 times more than oceans. Flying rivers are responsible for sustaining rainfall in the Amazon and South American region. A study by Brazilian climate scientist, Antonio Nobre, has determined that without the flying river, 70% of Brazil would turn into a desert.

A monsoon is the reversal of winds accompanied by heavy precipitations.
The monsoon is much more than rain — it’s a collective mood, a shared experience across communities and across time, and deeply ingrained. Artists and poets have tried to capture it for centuries. Novelists use it as a plot device, and it provides rainy, romantic interludes in countless Bollywood movies. And the monsoon is an economic force, particularly for the small farmers who get three-quarters, or more, of their annual rainfall from it. A good monsoon can bring plenty, a bad monsoon, hardship. And in the past, a terrible monsoon could bring famine.
The monsoon is becoming more erratic because of a basic bit of science: Warmer air holds more moisture. The moisture accumulates in the atmosphere and can stay there longer, increasing the length of dry spells. But then, when it does rain, it dumps all that moisture in a very short time. It can be a month’s rainfall or a week’s rainfall in a few hours to a few days.

Fireflies belong to the family of beetles that has more than 2,000 species, most of them light emitting. They produce light, through a chemical reaction inside their abdomen, primarily at dusk, to attract males. They live in marshes or in wet and wooded areas where their larvae find abundant food. Moist atmospheric conditions are very important for them to thrive. Fireflies have attracted humans since ancient times. Japanese have a particular reverence for fireflies and have set aside parks specifically for them, called hotaru. There is even a festival of fireflies each year in June. In poetry, they are a metaphor for passionate love.

When looking at the skyand all the aerial phenomena, we observed how artists through the ages had themselves looked at the sky and at the way light is reflected. We particularly loved looking at Japanese master Hiroshi Sugimoto’s “Seascapes”.  Shot in different parts of the world, always the same way, always in black and white, his photographs seem to fuse sea and sky and allow us to look at the Earth as a meditative experience

Wind is the natural movement of air or other gasses. It is caused by differences in atmospheric pressure which are mainly due to temperature differences. When a difference in atmospheric pressure exists, air moves from the higher to the lower pressure area resulting in winds of different speeds. The two major factors of large scale wind patterns are the differences in heat between the Equator and the Poles and the rotation of the planet. In arid climates, winds are the major source of erosion. But a positive role the wind plays is in seed dispersal. Seeds can float on the breeze or flutter to the ground.

Seeds are the embryonic stage of a plant’s life cycle. It is often contained within a fruit to help its spreading. Seeds serve several functions for the plants that produce them. Key among these functions are embryo nourishment, dispersal to a new location, and dormancy when growth stops during unfavorable times. Plants have evolved in many ways to disperse their offspring by dispersing their seeds - by wind, by water, by animals (for instance, seeds with hooks which attach to the fur or wool of animals). The seed we have embroidered on some of the garments is the Starflower - or Lomelosia stellata. Also known under the name Scabiosa stellata, it is native of southwestern Europe. The name Scabiosa is derived from the latin word ‘Scabere’ which means “to scratch”. It is found in abandoned fields, roadsides. Seeds from starflowers are dispersed by wind.

Rain water is droplets that have condensed from atmospheric water vapor and then fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water. Global warming is causing changes in the precipitation patterns globally. Current climate models indicate that rising temperatures will intensify the Earth’s water cycle, increasing evaporation. Increased evaporation will result in more frequent and intense storms, but will also contribute to drying over some land areas. The fine particulate matter produced by car exhaust and other human sources of pollution forms cloud condensation nuclei, leads to the production of clouds and increases the likelihood of rain. In some parts of the world, changes in atmospheric humidity and heat caused by climate change are expected to increase the intensity and frequency of extreme weather and flood events caused by atmospheric rivers.

Holocene is the current geological epoch. It began approximately 12,000 years ago. This established the modern world. Sea levels were stabilized, predictable seasons and reliable weather. This stability was fundamental. For the first time civilization was possible and humanity wasted no time in taking advantage of it. We domesticated rice, wheat, sorghum. The holocene was characterized by flowing rivers, cloak of forest, abundance of life and reliable weather. Throughout the Holocene we have had enough food to eat, water to drink and fresh air to breathe. 

This species of monkey, endemic to Brazil, is listed as Endangered based upon a suspected population reduction upwards of 50%. This reduction in number is due to habitat decline caused by deforestation for farming, cattle ranching and urbanization in both protected and unprotected areas. It is also a victim of continued high levels of hunting. Spider Monkeys need trees for displacement, food and shelter. The white-cheeked spider monkey had 5% of its range affected by fire over the past 20 years. They feed largely on the mature, soft parts of a very wide variety of fruits and play an important role as seed dispersers. They disperse seeds of more than 138 species of fruit trees. 

Epicormic growth is a plant response triggered by fire. It is the sprouting of dormant buds that lie dormant beneath the bark. Australia’s flora and fauna are adapted to fire through millennia of evolution, under normal conditions. It’s the forest’s regeneration mechanism after a forest fire.