Students who major in zoology spend a lot of time outdoors studying animals and their habitats. They also study the effects of humans on animals' environment and how to lessen these effects. Some jobs in zoology require an associate or a bachelor's degree, while others demand a degree that takes longer to obtain.
Every living organism needs a home, shelter or environment that provides the safety, ideal emperature and basic things it needs to survive. more science lessons: Asexual Reproduction
The idea of Earth's carrying capacity goes something like this: Humans need certain resources to survive at subsistence level -- most commonly air, food, water and usually some kind of shelter. A sustainable habitat is one in which supply of and demand for these resources are balanced.