Environmental Science Exam 1 Practice

A positive feedback loop is when the system’s response to a change amplifies that change, pushing the system further from its starting state. This self-reinforcing effect means the initial disturbance gets magnified rather than dampened, making the change more pronounced. For example, as ice melts, darker water or land is exposed, which absorbs more heat and causes even more melting. That amplification drives the system away from its original condition rather than restoring it. In contrast, a negative feedback loop tends to counteract changes, pulling the system back toward balance and stabilizing it. The other options don’t describe this amplifying mechanism: “matter” is not a process about feedback, and “eutrophication” is a specific ecological outcome that can involve feedback but is not the general term for an amplifying response.