Basically, an area's climate is defined by its range in temperature and the amount of moisture it receives. Changes in this climate can be gradual or rapid. Gradual changes that take place over millions of years are generally related to the motion of the earth in its orbit around the sun, or to the motion of the earth's crustal plates. Rapid changes may take place in a matter of years or hundreds of years, and are usually related to dramatic geologic events such as a volcanic eruption or the impact of a meteorite. However rapidly a climate may change, its alteration can change all of the major aspects of an environment, and therefore determine which species can survive and which and cannot.
Most plants require a specific range of temperature and moisture to survive.
If they cannot adapt to a change, they will die out. Supply of Food - All animals are ultimately dependent on plants for food. The animals may eat the plants directly, or eat other animals that eat plants. In either case, a change in climate can drastically change the type and amount of food available. Predators - A change in climate might favor one species that is a predator for another with the result that that the pray are driven from the area or killed off.