Answer:
This is a seasonal change, not a long-term change.
Step-by-step explanation:
The fault in Gwen's thinking is that an asteroid impact is a seasonal change and not a long-term change.
An asteroid impact involves the collision of astronomical objects and it is an event that only happens seasonally and within a short period. Hence, an asteroid impact can only cause short-term changes, and whatever effects they create can only last for a while.
A short-term event like an asteroid impact is not comparable to a long-term event like global warming, for example. Long-term events take time to produce effects and these effects can last for years, unlike short-term events.