But this has been exacerbated by human activities which have led to: 1) an increase in greenhouse gas emissions that causes heat to remain trapped within the troposphere, and 2) a decrease in ozone in the stratosphere, causing less sunlight to be absorbed by the ozone layer, resulting in a cooling of the stratosphere.
When measuring for floor tile the rule is: Length x Width + Waste = Amount Needed. Waste Factor will vary based upon tile size, layout, configuration of room, patterns, etc. Typical waste factor is about 10%. Add 15% for tile being installed diagonally or for a room with lots of jogs and corners.
Then divide the square footage of the ceiling by the square footage of one tile. This will tell you how many tiles you'll need. For example, if your tile is 24 long and 24 wide (2' by 2'), then the square footage for the tile is 4 (2 multiplied by 2).