Answer:
D) Human impact
Step-by-step explanation:
An environment's biology includes both abiotic factors like atmosphere, water, soil, sunlight and temperature; and biotic factors which are living components of the ecosystem. These factors lead to a gradual change of an ecosystem over time; however, humans drastically impact the environment through over-exploitation and pollution- we disrupt normal abiotic and biotic interactions. Furthermore, human impact can lead to population die-offs and extinction events, along with food and water scarcity.
Humans impact on the environment can manifest as:
- overpopulation- natural resources are over used, and habitats cannot support human communities;
- urban communities also expand by cutting down trees in deforestation- this leads to erosion and flooding;
- burning fossil fuels- this reduces air quality and adds carbon dioxide to the environment leading to global warming;
- pollution- adding contaminants to the atmosphere, waterways, soil etc.