---
title: "Positive Feedback Loop — AP Enviro Definition & Exam Guide"
description: "A positive feedback loop is a self-reinforcing cycle that amplifies an initial change, like melting Arctic ice speeding up warming, a key driver of climate change in Unit 9."
canonical: "https://fiveable.me/ap-enviro/key-terms/positive-feedback-loop"
type: "key-term"
subject: "AP Environmental Science"
---

# Positive Feedback Loop — AP Enviro Definition & Exam Guide

## Definition

A positive feedback loop is a self-reinforcing cycle in which an initial change leads to additional changes in the same direction. This amplifies the original change and can result in exponential growth or decline.

## Related Study Guides

- [9.5 Global Climate Change](/ap-enviro/unit-9/global-climate-change/study-guide/7uD60uqTmhzrFIlNVpw9)

## Review

### Related Terms

- [Negative Feedback Loop](/ap-enviro/key-terms/negative-feedback-loop): A self-regulating mechanism that counteracts changes from an equilibrium state.
- Tipping Point: The critical point at which a small change or disturbance can lead to significant consequences or irreversible effects.
- Amplification Effect: The magnification or intensification of an effect through positive feedback processes.