El Ni o events can also affect animals as well. In 1982-83, the warmer than usual waters killed kelp forests in the Pacific Ocean. Many sea birds that ate this kelp died as a result. This disruption in the food chain had severe consequences for other animals that relied on the sea birds and kelp for food. Scientists still don't have a clear understanding of why El Ni o happens, but they can usually predict as much as a year in advance when it will happen.
Gravity is the force that attracts objects to the Earth.
Lift is the force that a flying object creates to oppose this. It must also create a force to move it forward in the air. This force is thrust. Airplane engines ignite gases that generate thrust to move them forward. Changes in the pressure of the air rushing over their wings generates lift.