The various components of an ecosystem are interdependent. The producers make the energy from sunlight available to the rest of the ecosystem. There is a loss of energy as we go from one trophic level to the next, this limits the number of trophic levels in a food-chain.
Human activities have an impact on the environment. The use of chemicals like CFCs has endangered the ozone layer. Since the ozone layer protects against the ultraviolet radiation from the Sun, this could damage the environment.
The waste we generate may be biodegradable or non-biodegradable. The disposal of the waste we generate is causing serious environmental problems.