Before 2105 : During the middle 21st centery the Buy n Largecorporation assumed control of the planet's entire economy, including the government.
2105 AD : .The population had reached 200 billion. After Buy n Large gave the right to everyone to spend and buy the planet soon came to the position that there was no place where to put the trash. After Buy n Large failed to dispose all that trash they created an "amazing plan", that they thought the best and would work, called : "Operation Cleanup". The plan was to evacuate all the population ( except some who stayed behind ) away in different parts of space while back on Earth WALL•E's ( Waste Allocation Load Lifter: Earth class) robots and huge mobile incinerators would take charge of cleaning up. Thousands of Starliners where build all around the world, so the people would live safe and happy far from " Home" in the comfort and the luxury. Operation Cleanup success would be followed by "Operation Recolonize" . However back on Earth the toxins where rising and the WALL•Es where faiIing. After the CEO of BNL that time Shelby Forthright saw that his plan was failing and everything was becoming worse he ordered all robots to be shut down (exept one) and evacuate all of the population left. He also secretly sent the A113 Directive to all Autos on the year 2110 to cancel Operation Recolonize as he deemed that Earth would never support life anymore.
Earth was left without population , and the toxins also destroyed all plant and animal life ( maybe some animals survived somehow ). Aboard the Starliners, over the centuries, each new generation of humans grew more and more obese, losing bone mass in the process, due to over exposure to micro or artificial gravity and forgot about the "Home".
2805 AD . The last remainig WALL•E unit continued to obey his directive everyday and doing the same job over and over : creating cubes from trash and building colossal towers from them, while there were no humans to start the incenerators. Earth was covered in trash and suffered from sandstorms and torrential downpours. One day from the Axiom (one of the biggest BnL Starliners ever made) an probe ship was sent on Earth in the exact city where the Axiom was launched 700 years ago .An EVE unit (Extraterrestrial Vegetation Evaluator) was deployed from the probe ship and began an operation in search for a plant life.The unit was successful in finding an example of positive plant life with help of the last WALL•E. The plant caused the unit to shut down wich alerted the probe ship to come back for transport to the Axiom. This plant was succesful and proved that plants where indeed growing in city ruins. The plant was put in the holodetector so the Axiom made an automated hyperjump back on Earth. Humans began rebuilding again with the help of robots making Earth cleaner and greener as ever before.