You can classify them in what phase they are in: solid, liquid, gas
You can classify them in Sizes
You can classify them by the number of moons they have
You can classify them by distance from the sun
You can classify them all as heliocentric or orbiting/circling around the sun
You can classify them by color
The climate change impacts a coral in many different ways. But the main reason that could happen is if the climate were a coral lives is too cold and it begans to die. Corals have feelings toi, when they get a sense that they are going to die they try to leave but if they can't they will just die.
Corrects a persons errors they made
Hope this helped!