Population Changes Overview Questions In this Exploration, you will learn how climatic changes can affect the population of a species. You will understand how one species affects the population of another species in the ecosystem. Questions What does population change mean? Answer: 2. How can change in the climate affect the population of a species? 3. Why does change in the population of one species affect the population of other species? Data Population in Cold water Warm water Microorganisms Small fish Sea birds