The atmosphere: 2000ppm (0.2%) of carbon dioxide 21% to 25% Oxygen 78% Nitrogen 200 ppm of methane Huge amount of water as well as different kinds of other components Humans could breathe in this atmosphere, but they may be uncomfortable, especially if they were required to work for a long time. It was also unhealthy for them to work under this atmosphere for a long time. Therefore, people often wore an oxygen mask when they had to go outside[7]. In other cases, people lived in small groups underground. Cities changed significantly such that it looks nothing like the cities of the past anymore. Everyone needs to rely on each other to survive and the economy relies severely on depleted resources. Most ancient buildings were ruined by the huge storm, high temperature and endless flood and water. People had to build shelters (prisons) as accommodations. A standard place suitable for people to live must contain the following characteristics: 1. the location. All man-made objects located in high places. The reason for that was that most artifacts were ruined by the rising sea level if they were located at a low altitude. 2. materials[8]. People used reinforced AAC as building materials, with small, double windows (the interlayer was vacuum). Mostly, the building only had one floor above ground, with several underground floors, and half of the first floor of the house was buried underground, preventing heat from entering indoors. There was usually a small room at the entrance of the building, and the small room was usually separated from the indoor and outdoor, and was used for transitional use. If someone wants to enter the room, they have to first cool down the air inside the room and then they can go indoors. Transportation: Most of the facilities were built underground, including workspace, entertainment and commercial centers. People tended to avoid going outside unless they had a reason to do so. There were underground elevators carrying people around the city and they could visit other cities through bullet trains. The train had a maximum speed of 1000 km/h. If they want to visit a place where no one has ever been to before, they could use a rig for the destination.