Many things on Earth would start floating if there were no gravity, Marshall Brain explains on HowStuffWorks.com. Without gravity, the air in the atmosphere would leap into space, and the water in oceans, rivers and lakes would disappear. This would leave the Earth with no air and water supply, causing all living things to die.
Brain concludes that no living thing would survive if the planet did not have gravity. According to the Astronomy Department at Cornell University, things not attached to Earth in any way other than gravity would fly off into space in a straight line, taking them away from the Earth’s surface. People would float gently upwards inside buildings until they reach the ceiling. Outdoors, things would float away gently, eventually floating at a faster speed as their straight line takes them farther away from the circular path taken by the spinning Earth. Even the atmosphere would float off into the outer space. On the other hand, those that are held down, such as trees and most buildings, would stay in place.
The Astronomy Department at Cornell University states that only around 0.3 percent of the strength of the force of gravity is needed to keep something from flying away from the Earth, if there were no gravity. Still, the Earth itself would likely break apart, because it is also held together by gravity.