Final answer:
The statement that hurricanes can cause storm surges that raise sea levels over 20 feet is true. Storm surges are significant threats, especially in areas with low elevation above sea level, such as Bangladesh.
Step-by-step explanation:
The statement is true: Hurricanes can push high mounds of seawater onshore as storm surges that temporarily raise sea level over 20 feet. A storm surge is a sudden rise in sea level in coastal areas during a storm or hurricane, primarily caused by strong winds blowing onshore.
Coastal cities struggle with even a ~0.25 m rise in sea level; when combined with high tides, storm surges can significantly exacerbate local water levels and potential damage. For example, most parts of Bangladesh are fewer than 40 feet above sea level and experienced devastating consequences due to storm surges from cyclones, highlighting the destructive capacity of such events.