Keiñei

Keiñei (PX̂R-1d; ICCD Esshaii 3.B.1.4.7.4//4) is the fourth planet of the Řaqani system with a KIPU Habitable Planet Classification of M4n0. It possesses a number of natural satellites including five large asteroids, the largest of which is a spherical pale body tidally locked to the planet known as Ueqai. Its surface is 45% land by area divided between three large continents with the remaining 55% of the surface being water coming in the form of two large oceans and numerous large seas and lakes. It is the original homeworld of the Keiñuan species.

Keiñei is situated comfortably within the habitable zone for organic water-based life and its entire land area including the poles is dominated by rainforest, with more arid regions featuring extensive grassland. This biological productivity owes its existence to the planets extreme volcanic activity which constantly regenerates the upper atmosphere with water vapour, carbon dioxide and other greenhouse gases, perpetuating the planets idyllic greenhouse climate. The planets climate is prone to feedback loops caused by sudden changes in greenhouse gas levels, and it has gone through several periods of extreme glaciation and aridity in its geological history which have been responsible for many mass extinction events. The latest of these was caused by early Keiñuan industrial activity, resulting in average temperature increases of up to 10K that lasted 2394 years before it was undone by terraforming efforts.

Topologically the surface is relatively flat due to chaotic tectonic movement limiting orogeny. However this has not prevent chains of volcanic mountain ranges and enormous caldera lakes from forming which mar the entire surface. The planets extreme volcanism makes Keiñei's crust very mineral rich, a property which many have contributed to accelerated Keiñuan technological development and industrialisation.

The Cislunar Habitat cluster in orbit around Keiñei is the capital of the Psohx̂ract Union. The planet itself is designated a supranational monument on which no permanent habitation or exploitation is permitted in order to preserve the ecosphere. However it is a popular tourist destination, especially for safari tours of the planets diverse environments. Ruins of the pre-fall Keiñuan civilisation still remain ion the surface in stages of advanced decay.

History
The Řaqani system formed 9.6 Billion standard years ago, during which Keiñei was created in the far inner system before migrating to its current position after a a red dwarf passed through. At some point afterwards the protoplanet Ueqai was captured along with the five main asteroids that orbit the planet; Aeqa, Kasřa, Huřonu, x̂iqey, and Ñei. Organic, unicellular life first emerged 6.2 Billion years ago and soon diversified and colonised the entire planet. The planet is very geologically active and has a large number of small tectonic plates that constantly spawn chains of volcanic mountains across its surface. The regular, controlled activity has meant that particularly violent eruptions are extremely rare and provided a stable and constantly cycling environment in which multicellular life has thrived.

The planets biosphere is warm and wet, with high levels of greenhouse gases such as carbon dioxide and water vapour trapping heat and creating a uniform environment across the planet. Global rainforests with high biodiversity typically dominate the land, however the planet has a semi-regular cycle of transforming from its regular warm-wet 'greenhouse' phase into a hot-arid 'dusthouse' phase. These arid phases are often caused by a hyper saturation of the upper atmosphere with greenhouse gases that raise the temperature too high for the rainforest biome to compensate for, leading to a positive feedback loop of drying and dying until a new equilibrium is formed with reflected sunlight from higher albedo desert scrubland. The arid climate may persist for tens of millions of years, with vestiges of the old rainforests that have clung to life at the cooler polar regions recolonising the planet once greenhouse gas levels drop and the temperature falls. Despite this, the planet is unlikely to enter a catastrophic climate runaway until Řaqani progresses along its evolutionary path, as the chaotic tectonic activity regulates the atmosphere by constantly exposing new carbon-sequestering rock, acting as a powerful greenhouse gas sink.

Keiñuans are native to Keiñei, and are descended from a group of avian omnivores. The species was adapted to life in dense forest canopies, and was flightless and quadrupedal for enhanced climbing and dexterity. During a period of aridity caused by changing ocean currents in the planets equatorial regions, the species was subject to selection pressures that favoured increasing intelligence and cranial capacity, eventually evolving to produce a species group with upright morphology and digitigrade stance classified by the imperium as a type 2 biped. The volcanic activity of the planet became an issue for the progression of the species as it impeded their ability to successfully develop complex agricultural societies. As soon as they did, however, the abundant resources of Keiñei lead to a extremely rapid technological progression and industrialisation.

Overexploitation of natural resources, deforestation, and unregulated oceanic and atmospheric pollution produced by Keiñuan industry started to trigger the beginning of a new hot arid phase, with the positive feedback loop of globally increasing temperatures and aridification greater than the environment could compensate for promising to rapidly alter the planets biosphere. It was predicted that the planets temperature would rise by over 7K, and that only a fraction of the population would be able to be supported in the changing environment. Initially a quasi-closed system of domes was envisioned to perpetuate comfortable life on the planet until the damage could be reversed, however warfare, political corruption, mismanagement of resources, falling public support, and concerns from the scientific community that pollution from the domes would continue to worsen the climate for those not inside caused the project to be scrapped. Inequity caused political uprisings across the globe which raised tensions between Keiñuan political entities.

Over a century later and conditions worsening the now fully spacefaring Keiñuans considered a different solution; relocating the population to their off-world colonies and artificial habitats constructed around the Řaqani system. However, with resource scarcity becoming an increasingly pressing issue, a global war erupted between the major powers, in which multiple asteroid strikes engineered to disperse greenhouse-enhancing aerosols in the upper atmosphere were deployed, killing countless people and greatly accelerating the pace of the environmental shift significantly. Nonetheless, evacuation continued -predominantly through a system of of electromagnetically launched spaceplanes and skyhooks - and all but a minority of the population who chose to remain were relocated into space by [year]. Much of the population remained in close proximity to the planet, living in habitats built on Ueqai and within the planets asteroids that would later be used to build the cislunar habitat cluster. For the next several thousand years, Keiñei's climate continued to degrade, with a period of increased volcanic outgassing accelerating the process and causing a peak average temperature 10K greater than it was prior to industrialisation. The positive feedback loop of heat transformed the global environment faster than was believed possible, resulting in a great dying of the remaining rainforest outside of the poles and causing the planet to rapidly enter into its next phase of aridity.

With the Keiñuan invention of the FTL drive in the year [] and the economic productivity it allowed, resources were set aside for a terraforming project to return the planet to its former humid state. First, a number of metallic asteroids and Ueqaian Strata were brought into position over the planet and broken down into a ring. This material was then used for constructing swarms of orbital mirrors that reduced the amount of sunlight reaching the planet by a few percent, cooling it down to its former temperature. After the mirrors were completed and the temperature reduced, engineered microorganisms were introduced that would rapidly fix greenhouse gases from the atmosphere over an accelerated timespan. After this was initiated the old rainforests were spread and cultivated across their previous range, and the numerous species that had become endangered or extinct during the crisis were slowly reintroduced to their old habitats over several millennia. Over time the ecosystem returned to its previous warm, wet, rainforest-fuelled equilibrium, and with the establishment of the Psohx̂ract Union in [date] the final orbital mirrors were dismantled, leaving only a ring of leftover material that can still be seen in the present day. The environment of the planet would take thousands of years to stabilise fully and required numerous interventions to prevent reversion to the arid phase, but would eventually become truly self sustaining. Due to Keiñei's orbit bringing it closer to Řaqani, at some point in the next half million years the planet is predicted to naturally enter into another hot arid phase.

Ecology
The types of life that flourish on Keiñei have been largely shaped by its geologic activity, with volcanism capable of changing local climates extremely rapidly, whilst the planet as a whole has a rather uniform climate due to the greenhouse gasses constantly replenished in the upper atmosphere. This has preferentially selected for a large variety of migratory avian life and aerially dispersed plant life.