There is global warming because of increased CO2 and Methane in the atmosphere. The CO2 is mostly from emissions from cars and such. The Methane is mostly from cows, meaning beef and dairy. This gets trapped in our atmosphere, letting heat warm the earth but it traps the heat. This leads to an increase in temperature.
Answer: Bassically, certain gasses like CO2 (Carbon Dioxide) that come from stuff like burning fossil fuels and global warming, they heat up the earth, are wastes and are used as fuel.
Water which collects as droplets on a cold surface when humid air is in contact with it