Final answer:
A forest fire is a short-term environmental change that has immediate but not always lasting effects on ecosystems, unlike long-term changes such as ice ages or mountain building.
Step-by-step explanation:
The environmental change that is considered as short-term is a. Forest fire. Forest fires can alter habitats and affect local ecosystems but typically do not have the longstanding impact that an ice age or mountain building would have. Changes like ice ages, mountain building, and significant alterations to solar energy patterns are considered long-term changes since they occur over very extended periods, altering the planet's climate and geography on a larger scale.
Short-term environmental changes generally refer to those that occur quickly and have immediate but not necessarily enduring effects on the environment. Events such as forest fires are dramatic but often limited in their temporal scope when compared to geological or astronomical changes that unfold across thousands or millions of years.
A short-term environmental change is a forest fire. Forest fires are events that occur relatively quickly and have a rapid impact on the environment. They can cause significant damage to vegetation and wildlife, but the ecosystem can often recover over time.
Other examples of short-term environmental changes include unseasonal rainfall and changes in the life cycles of insects and animals. These changes can have temporary effects on the ecosystem but may not have long-lasting impacts.