Precession is the change in the direction of the axis, but without any change in tilt; changes the stars near the Pole; It does not affect the seasons. If warming reaches 2 degrees Celsius, more than 70 percent of Earth's coastlines will see sea-level rise greater than 0.66 feet (0.2 meters), resulting in increased coastal flooding, beach erosion, salinization of water supplies and other impacts on humans and ecological systems.