Earth

"However, scans show an almost complete failure of Earth’s biosphere- only a few remote pockets in the Northern Hemisphere seem capable of supporting a human population, most of this using terraforming equipment to keep this. The destruction of Luna (And the wreckage of the previous battle) impacting on the planet has left the planet in a semi-permanent state of nuclear winter, with an estimated 12,547 impacts of significant nature per day."

-Anton, AI of the UCE  Minutes to Midnight in a summary of OPERATION: BLUE SKY to Navy Admiral K.A. Tyler

Overview
Earth, the third planet in the Sol System (Sol III), was the world on which Humanity was seeded and evolved on. It had an incredibly diverse biosphere and climate before the events of 2654. However, the First Battle of Earth left the planet in a state of ruin, described as being in a "semi-permanent state of nuclear winter" due to the large amounts of debris thrown down on the planet by the wreckage of ships (Mostly human) and destruction of the moon.

History
Over between 60-130 million years before recorded history, the Sh'Kaali injected the Human genome into the evolutionary cells of early primates and mammals, ensuring that life would evolve to produce the dominant species. There, humans would proceed to evolve like any other species, creating and utilising increasingly more advanced technology for scientific and military purposes. In the early half of the 20th century, much of Europe would be racked by two devastating world wars, and from here, war stopped temporarily. It was in the late 20th century and early 21st century when it was realised that the 'point of no return' had been passed regarding pollution- the excessive pollution produced by industrial activity had caused a downward spiral of rising water and temperature. For the majority of the 21st century, most nations decided that it would be equally benifitial to put aside their differences to help put research towards space exploration and terraforming efforts. However, the environmental damage had already been done. despite colonisation of other worlds, Earth's vast water reserves were being thawed from polar ice caps, and a large portion of the planet's coastline was submerged, including many key cities that were situated in flooded areas. This would cause mass-migration to the mainlands of the planet. The total stress of supporting millions of refugees was not without toll; food shortages swept the planet leading to more forestland being cut down for energy and farmland. Without these rainforests, the atmosphere soon became clogged and polluted, being toxic after more than a few days exposure.

Soon after the end of the Exilion Wars, contact was established with extraterrestrials. The aliens would help humans by partially terraforming the planet to a more habitable state without need of rebreathers, though this required huge devices installed across the globe toconvert Carbon Dioxide to Oxygen, with an estimated recovery time of the planet to be thousands of years. Despite this, Earth was made capitol of the Imperium and soon supported a population of billions around its surface and space.

In 2654, utter devastation would be unleashed by the S'pher in the First Battle of Earth; in the early stages, tens of thousands of vessels would be called to the planet, only to be destroyed in-atmosphere by the S'pher fleet. However, the S'pher began to take heavy losses as the shock of the surprise attack wore off, and so, this called for drastic measures; a Luna-Class Planetary Devastator would show up in the battle, and proceed to completely destroy Earth's moon; Luna. Luna would be split into three main pieces, with roughly one quarter of the moon impacting the central Pacific Ocean, causing immense Tsunamis, Earthquakes and Volcanic Eruptions across the planet. However, this was only the start; trillions of objects and pieces of dust from the combined aftermath of the battle and moon began to rain down on the world, as the non-stop impacts would continuously send massive amounts of dust in the atmosphere. After the initial 'steel rain' began to become less often, S'pher ships would descend onto the planet itself. The next targets were the 5,000 Terraformers stationed on various points around the planet, of which 2,491 remained in Europe and North Aisa. The Devastator's size would-alone- cause immense gravity fluctuations, furthering intensity of natural disasters around the East Aisa area. Elsewhere, Terrafomers were going offline one-by-one, slowly making the atmosphere toxic to all life forms that had somehow survived the barrage unscathed. Within 72 hours, almost 100% of all life on the planet had been wiped out.

There would be some habitable areas, though; intense global warming in the aftermath of the invasion had significantly thawed ice in Siberia and Scandanavia, allowing these areas to remain barely able to support life. Pre-War Britain, having situated UCEDF HQ, was installed with a similar shield to those used on Exodus and Thanator, so was able to stave away most of the impacts. This area would become the last beacon of hope for survivors on-planet; the S'pher could not enter the area, but humans couldn't leave it. The strands of humanity that inhabited Britain would become a resistance movement against the occupation. S'pher Landers would begin to extract Iron from Earth's Core by drilling down into the planet's mantle and beyond, keeping some humans as labour and so, keeping generators in the newly-dried Pacific Continent.

In 2702, OPERATION: RECLAMATION would be launched by all branches of the UCEDF. This wuld become the Second Battle of Earth as every known Human in service of the UCE would fight in a last-ditch attempt to retake the planet.

Planet Status as of 2702
"One finding of my own is another consequence; the re-classification of Earth to a Type-3 world, in compliance of the Imperial World Classification Act."

-Navy Admiral K.A. Tyler, reviewing OPERATION: BLUE SKY's findings.

Needless to say, the planet was unrecognisable after the battle, with almost all of the surface being declared completely uninhabitable. Listed are the states of various areas of the planet. It should be noted that areas not listed can be presumed;
 * Irradiated
 * Completely Levelled/ Destroyed
 * Toxic
 * Flooded
 * Any combination of the above

Central Alaska
Before the invasion, the Alaskan mountains harboured several Alpha-Five bunkers- ARMAGEDDON Complex. These bunkers stayed mostly hidden and intact throughout the event, and are thought to be the only safe area on the planet. If BLUE SKY findings are to be believed, the complex is transmitting a message on a frequency not scanned by the S'pher. This message reads 'Alpha-Five' repeatedly, and is believed to hold the secret to winning the war.

North-West America
From Mexico to the Alaskan coastline, the entirety of Western America is completely flooded up to the now-volcanic Rocky Mountains. In additon, the Yellowstone Super-Volcano has and continues to erupt every day, creating a permanent ash cloud over the entire continent.

North-East America
Everything East of the Rocky Mountains is wasteland; what wasn't incinerated by Yellowstone, the impact of several large pieces of rubble and floods is nuclear desert. In a permanent night, the North Americas are freezing nuclear desert. No life survives here.

Central Americas and Carribean
Almost all of Mexico and  the Carribean islands are massively flooded. In effect, the sea now divides North and South America.

South America
Almost all of (What used to be) the Amazon is now flooded marshland, with uninhabitable desert below it and to the rest of the continent. No life survives here.

Central Pacific
After the impact of L-3 (The designation of the chunk of Luna that impacted on the area), the Pacific experienced huge Earthquakes, Tsunamis and Volcanoes; including entire plates shifting. Taking this into account, the S'pher now occupy this area, drainign seawater for access to the undersea area of the many trenches and new plate boundaries. Here, huge drills dig into the mantle and core of the planet. There are several Terraformers here to sustain a viable atmosphere for the human labour shipped here regularly. One of the few sites where life can flourish, and has a great source of mineral ore.

Asia

The massive disasters unleashed on this area were magnified by gravity fluctuations caused by the Devastator. The entire area is huge peaks, reaching incredible heights thought to be impossible. Most of the Chinese area is flooded swampland. Several generators remain online, in areas where humans are kept by the S'pher for labour.

Europe
Most of the Mediterranean coast is completely submerged. Northern France continues to be livable, owing to the Terraformers kept in Britain. The rest is toxic wasteland.

Africa
Ironically, the least changed area remains one of the most hostile. Collapse of the Ozone layer near North Africa means that almost all of North Africa is exposed to lethal amounts of UV radiation, with the majority of the continental desert being littered with rusting hulls of downed ships.

Britain
Thanks to a shield-barrier installed centuries prior, Britain remains a safe haven for human refugees. However, the outside of this shield is blockaded by S'pher troops, with anyone coming near the barrier mercilessly killed. The passes between Britain and France and Scotland to Scandanvia are opened, leaving land passage across the previously seabed. The European Sea is being drained by the S'pher, for mining operations and to open a front for an all-out attack on Britain. It is estimetd that the survior camp will fall by 2710 if the UCE assault on Earth should fail.

It should be noted, that radiation on the planet is caused by three main sources;

A) The atmosphere has severely degraded, and lethal amounts of Solar Radiation are released on the planet

B) Nuclear weapons detonated all across the planet in the initial battle

C) Several ships and cities fusion reactors went critical not long after the battle, creating huge pockets of radiation on the planet. The ones that haven't completely blown up continously leak radiation into their surrounding areas