A layer of pulverulent sulphur covers parts of the hydrothermal site of Dallol in northern Ethiopia. It suddenly ignites into blue flames that scurry along the ground’s surface. This phenomenon is rare and has yet to be explained.

Human communities have always attempted to elucidate the mysteries of life and of the Universe. The world’s myths and religions rely on the quest to understand our origins. While scientists ask “how”, men, philosophers and believers question the “why”.

Pieces of ice and icebergs float and tintinnabulate along the Jökulsárlón lagoon in southern Iceland. Suddenly, the elusively intense Aurora Borealis ignites the skies. The luminous arc stretches, vibrates, amplifies and fills the heavens. It then vanishes in the glacial silence of the night.

Seventy million years after the Earth was initially created, several layers began to form when the planet was still very hot. The rotation of a solid kernel inside a liquid core is the source of the Earth’s geomagnetic field which still protects it from the solar winds that produce polar auroras.

The highest natural temperatures –as high as 1 200 °C –have been recorded in the Nyiragongo volcano’s lava lake, in the Democratic Republic of the Congo. As the lake slowly overflows, it makes a backwash sound that can be heard from the very top of the crater.

Chaos and disorder reigned supreme in the kingdom of Hades, the master of the Netherworld in Ancient Greek mythology. This god gave his name to the Hadean, the most ancient eon on the geologic time scale, which went from –4.5 billion to –3.8 billion years, before giving way to the Archean period.

The Nyiragongo is one of the most active volcanos in the African rift; it is located in the Virunga Mountains in the Democratic Republic of the Congo. Its lava lake bubbles at the bottom of a 500 metre-deep caldron, glaring at dusk’s glimmering lights with its Cyclops eye.

The basalts produced by primitive earth formed rafts of terrestrial crust, similar to those floating on this lava lake. As they weighed more when they cooled, they sank in the depths of a magmatic ocean churned by convection movements.

The Tavurvur volcano in Papua New Guinea erupts often. It is one of the 452 volcanoes in the famous “ring of fire”, as oceanic plates sink under the continental masses along the Earth’s 40 000 kilometre-long seam.

The earth’s infancy was punctuated by gigantic volcanic eruptions in which huge amounts of carbon dioxide, sulphur and chlorine were released in the atmosphere, after having been initially stored in the Earth’s deepest recesses.

These lava fountains go up as high as 200 metres. They illustrate the fissure eruption of the Bárðarbunga volcano in northern Iceland.

A mid-ocean ridge emerged in Iceland. It is an underwater chain of mountains spanning a distance of 65 000 kilometres, discovered during seabed explorations in the 1970s. Effusive eruptions often occur there. Fluid lava flows spread and contribute to the expansion of the ocean floor.

The Eyjafjallajökull glacier changes colours. From bluish white, it turns to deep black, as it finds itself perforated by the explosions of the underlying volcano. The European airspace was shut down for several weeks due to the ash plume being pushed by north-western winds.

A sudden surge of climate warming occurred while Pangea, the last of the supercontinents, was dislocating. This rise in temperatures was provoked by immense outpourings of lava, the latter of which are still visible in Antarctica, Australia and South America. Such climate change led to one of the Earth’s large-scale biodiversity crises, 182 million years ago.

The Tolbachik volcano started erupting in 2012. It discharged fountains and torrents of lava in the middle of the immaculate lands of Kamtchatka, in eastern Russia. More than 200 volcanoes are present in this wild peninsula, some of which are in constant eruption.

The Earth went through its first ice age well before the Quaternary period, between –2.4 billion and –2.1 billion years. It was the longest glacial period in its history. The entire planet may have been confined in ice.

The Kilauea volcano, on Big Island in Hawaii has been erupting for thirty-three years. It spits out rivers of lava, which flow through tunnels of solidified magma, before setting their claws in the ocean.

Volcanism in Hawaii is typical of “hotspots”. These upsurges of mantle material end up piercing the drifting tectonic plates, just like a blowtorch would perforate a moving piece of sheet metal. These abnormal mantle sources contributed to the fragmentation of the supercontinents, including Pangea, which started to dislocate only 250 million years ago.

The full moon rises. With its cold light, it magnifies a surprising planet: the hydrothermal site of Dallol and its many shades of colour. The site in turn illuminates the Danakil Depression and the arid expanses of land located at the very end of the Ethiopian rift.

The Dallol site is magical and sulphurous. But will this haven of beauty –the result of the interaction between volcanism and hydrology– manage to resist against the exploitation of huge potash deposits in the salt plain?

Sandstone vessels skim over an ocean of marlstone and clay. Since the more tender layers of Luna Mesa have faded away with erosion, its tabular surfaces are now visible near Caineville in Utah.

2.5 billion years ago, the Earth evacuated incredibly large amounts of heat. This allowed it to surround itself with a lighter solid crust which floated above a mantle core. Modern Earth was about to embark on a new journey.

The “Half Dome”, a gigantic block of granite, is caught in a storm of snow and rain, crowned by the fleeting intensity of sunset. Yosemite National Park, California.

Towards the end of the Pleistocene, from –110 000 to – 10 000 years, glaciers became powerful agents of erosion as they progressed with unrelenting slowness. Rocks were shaved off. Large valleys, such as that of Yosemite, were carved; these were made up of flat floors and straight sides.

The very first glimmers of sun ignite the steep cliff of Toroweap Point, at the heart of Grand Canyon National Park in Arizona. Eight hundred metres below, the Colorado River glides in silence.

“If human beings tried hard enough, they could remake the Parthenon ten times. But they could never recreate a single canyon, the latter having been moulded by millennia of patient erosion, in which sun, wind and water combined their efforts”. Jean Dorst, biologist.

Before the Glen Canyon dam was filled, 500 000 tons of sediment and rock debris drifted in the Colorado River every day. The river’s sheer strength led to thick layers of sandstone being slashed. Shapely rock and water formations emerged as a result, such as the near-perfect Horseshoe Bend in Utah.

Water strongly contributes to the alteration of rock. It inserts itself through its mineral network, it pulls rocks away from cliffs and mountains and leads stone matter to fill out pits and valleys. Varying climates finalise the moulding of high ground.

The ebbing tide progressively uncovers the rocks that have been darkened and grooved by waves on the Anse Source d’Argent beach at La Digue Island.

The granite islands of the Seychelles archipelago are crumb-like parts of the oceanic crust which scattered during Pangea’s fragmentation when the Indian and African tectonic plates deviated.

The Skjálfandafljót River races through the central Icelandic plateaus before plunging in Aldeyjarfoss over a rocky escarpment in a thunderous roar. The flow reveals basalt with columnar jointing.

Water, the source of life, consists in the largest annual displacement of a chemical substance on the Earth’s surface. It is also an erosive force under all types of climate.

The Valle de la Luna appears on the edge of the huge salar de Atacama in Chile. The Licancabur volcano hovers over these vast badlands which are composed of salt, sand, and gypsum. They were overturned and straightened by the upheaval of the Andes.

The progressive uplift of the South American continental plate led to the highest tectonic elevation known. A height difference of 14 kilometres exists between the summits of the Andean mountain range and their roots, which drop 7 000 metres deep into the oceanic trench.

Clays were hollowed out by rain, leading the finer elements to fall. Zones that were protected by a “hat” – a block carved out of a solid layer of sandstone – were progressively cleared. This is how these “fairy chimneys” formed at the Grand Staircase-Escalante National Monument.

“Land elevations are the Earth’s bouts of fever” says Patrick De Wever, geologist. For most of its history, the Earth was a monotonous flat surface on which rivers and waterways erred.

The meandering Þjórsá River contains fire sparks that are reddened by iron oxide. It is also interlaced with bright green ribbons that were stripped of decomposed organic compounds lost to erosion. The river snakes through the ashen plains of southern Iceland.

During the long periods of time in which the Earth was a vast flat surface, rivers and waterways rumbled lazily while making deposits of alluvium suffused with iron pigments.

After having been buffeted by the ocean and weathered and polished by waves, the iceberg becomes a smaller piece of ice and ends on the southern Icelandic coast’s dark shoreline, lit by the brightness of the winter sun.

Throughout the Earth’s history, continental climates were the result of land being contained in supercontinents. Cold winters fostered the creation of ice caps. When lands started dislocating, oceanic climates emerged. The latter contributed to the melting of ice and to the rise of sea levels.

Life delicately returns among the whitened skeletons of trees. Ash and acid rain asphyxiated the forest during the eruption of the Tolbachik volcano in the Kamtchatka peninsula in the Russian Far East.

After each mass extinction – triggered by meteor impacts or by volcanic paroxysmal episodes – life has always managed to spring forward, evolving once more based on the remaining surviving species.

Cacti, such as these beavertail cacti, live at a slower pace for a good part of the year. Yet they also contribute to the flowering of semi-arid regions in the western United States. Joshua Tree National Park, California.

The morphology of plants has changed due to the diversity of ecosystems and climatic variabilities. In desert areas, species develop thorns or glossy sheens to halt water evaporation.

The bold green tones make us think of a soft carpet of moss. But when one touches the llareta plant, it is as rough as rock. Its short and tough leaves and its tightly arranged branches are designed to resist cold temperatures, dry air and intense sun radiations.
Lauca National Park, Chile.

The first truly terrestrial plants were mosses which still belonged to humid environments. They appeared 440 million years ago. It took a long time for them to break away from humid settings, since they were conditioned by an aquatic mode of reproduction.

The Tundra, which is usually austere, transforms into an ocean of fire during the short Arctic autumn. It sits at the feet of the blue Vatnajökull ice cap in Iceland.

Tropical vegetation diminished following the most recent glaciations. To survive in the cold, trees invented autumn; leaves were shed in the coldest period of the year to limit the loss of liquid when water supplies could not be renewed.

The Pantanal wetlands sit between Brazil, Colombia and Paraguay. This territory alone represents 3% of the planet’s humid zones. Its floodplains are covered in water lilies that bloom at night.

Over the course of time, flowers and pollinators ingeniously adjusted to each other. But, while bats are attracted to the nocturnal blossoms of certain flowers, water remains the ideal pollen conduit for aquatic plants.

The Epupa River’s “leaping waters” flow between the baobab trees. This green haven extends like a welcome break between the deserts of Namibia and Angola.

During the Devonian, from – 417 to – 350 million years, important changes profoundly altered the vegetable kingdom. One of them was the appearance of wood, a magical substance that could stiffen tissue.

The fog hovers over the maple trees in the Gotjawal forest; it clings to the slopes of the Hallasan volcano, on Jeju Island in South Korea, just like a paint brush soaked in water would glide on grainy paper.

Flowering plants, or angiosperms, (literally meaning “seeds encased in a container”) include all plants that bear fruit, as well as broadleaf trees. They appeared 140 million years ago and quickly replaced the gymnosperms (plants which have a naked ovule), mainly represented by conifers.

The fleeting evening light ignites the dream-like Anse Lazio beach before the arrival of a new tropical storm. Praslin Island in the Seychelles.

Residents and non-profit organisations are attempting to reforest "Palm Island" after over two centuries of soil erosion and forest fires. The French explorer Lazare Picault fell in love with the island's luxuriant environment in the eighteenth century.

In Daintree Forest, in northern Queensland, Australia, fan palms deploy their wide foliage in the tropical underbrush in an attempt to capture rays of sunlight and a few drops of rain.

The engine behind plant diversification isn't based on fighting or on competing species. Instead, it depends on mutual help, on solidarity and on a symbiosis with the animal kingdom, since one life form could not live without the other.

The Cheonjiyeon waterfall on Jeju Island in South Korea reveals the columnar jointing of a thick lava flow. Reeds and ferns find cavities in the rocks and benefit from the surrounding humidity to grow.

“The first molecule of life is water! Because water is essential to life. Everything stemmed from there”. Gilles Boeuf biologist.

The world's biggest fish appears under the water's surface and is escorted by remoras. The whale shark has a flat head, wide-set eyes and a laidback look. It only eats plankton, krill and small prey.

Plankton life continued to diversify and evolve. 530 million years ago, the ancestors of fish did not have vertebrae or jaws. Instead, they possessed an internal cartilage frame which sharks and rays still carry to this day.

Yacare caimans scramble to find the few water holes that the dry season has spared in the Pantanal wetlands in Brazil. Fights over the last of the fish can be fierce.

In the Mesozoic era, from – 250 to – 66 million years, reptiles reigned the animal kingdom. They bore crests, horns or feathers; they were bipeds or quadrupeds, carnivores or herbivores, giants or the size of a sparrow. Dinosaurs, those “terrible reptiles” colonized all of the ecosystems of the planet.

The Megasoma acteon, a beetle the size of a hand, arrives whirring through the trees. It lands on a liana in the humid underbrush of the Guianese tropical rain forest.

Arthropods represent 80% of the known animal species today. They form the most diversified phylum in the animal kingdom.

The Smilisca phaeota is an arboreal frog; a dark mask elongates its eyes. Still dizzy from its nocturnal amorous embraces, this male individual has been caught by an arboreal snake. For hours, the amphibian resists by swelling like a ball, but the reptile manages to swallow it progressively.

In terms of evolution and natural selection, scientists believe that predators co-evolve with their prey. With time, hunters learn to thwart their victims’ adaptive strategies, which would explain why some predators are extremely specialised.

The interior delta formed by the Pantanal wetlands fills up during the rainy season. Fish migrate by crossing the flooded plain and returning to breeding sites, which are scrutinised by birds. Jabirus and cormorants depart from Rio Negro after having fished in the morning.

Which animal flew first? Was it an arboreal dinosaur who had acquired the ability to parachute safely to the ground? Or was it a runner who moved appendages that were already equipped with feathers, thus allowing it to accelerate and take off?

In October, wild swans leave their homeland, the great plains of Siberia, to escape temperatures as low as – 50 °C. After having covered 8 000 kilometres and flown eighteen hours without stopping, the birds land in Hokkaido, Japan’s northern island. Thousands of swans are set to spend the winter in a slightly warmer climate, since temperatures never fall below – 30°C here!

The feather is a magical substance and performs many functions. It is a fabulous thermal insulator, which is further reinforced when the bird ruffles its plumage. It is also light and incredibly resistant, and its colours can serve to camouflage the animal or to enhance its seductive display.

After having roamed for months on the pack ice that closes the Hudson Bay in Canada, polar bears touch ground. The cubs learn to hunt and fight.

The polar bear is the master of the Arctic since it does not have a natural predator. Despite the reduced surface area of ice in the summer and the thinning of older layers, the bear population seems to have stabilised. For how long?

Australian sea lions only reproduce on the southern and western coastlines of the continent-island. An estimated 12 000 animals now live in these areas, and the species is considered to be highly endangered.

Several characteristics remind us of the past land life of marine mammals: they nurse the young, their skeletons still bear traces of former terrestrial members, and they engage in aerial breathing which forces them to come out of the water regularly.

Animals have been alerted by a noise or a suspicious smell and run frantically. Dust rises and thickens the early evening sky, just as a solitary lioness steps forward to drink peacefully.

In the mid twentieth century, 200 000 African lions were estimated to roam the continent. There are now only 20 000, and half of them could be wiped off of the African map within twenty years. Such a disappearance is due to the fact that their land is being increasingly cultivated, their preys are slaughtered, and their bones and skins are used for Asian remedies.

Sifakas are indifferent to the sharp limestone blades and to the acute needles of Tsingy de Bemaraha in Madagascar. These animals (Propithecus) dance across the karst, and are attracted to the leaves and fruits of the surrounding forests.

Primates arrived 35 to 55 million years ago. Humans took their time. The first hominid is 7 million years old, while Homo Sapiens is 200 000 years old. But since the arrival of humans on Earth, many factors have contributed to destroying the world’s natural habitats: climate change, bulging demographics, pollution, and biodiversity loss. Humans are setting the scene for a sixth extinction. How much time is left to avoid such a terrible scenario?