The phrase "significant impact" refers to an effect or influence that is noteworthy, substantial and important. It indicates a noticeable change or outcome that has a deep and lasting impression on something. The term can be used in various contexts such as describing the effects of a natural disaster, the consequences of a decision, or the impact of a new technology. In essence, it refers to an effect that is noteworthy, substantial and important enough to make a difference or change in a situation.