What differentiates positive from negative feedback loops?

Positive feedback loops amplify changes, while negative feedback loops counteract and stabilise changes in a system.

In more detail, positive and negative feedback loops are fundamental mechanisms that regulate various processes in both natural and human-made systems. They are essentially self-regulating cycles where the output of a process is used as input in the same process. However, the way they respond to changes is what differentiates them.

Positive feedback loops are cycles that amplify or increase the effects of changes. They are self-reinforcing cycles where the output of a process enhances the process itself. This means that an increase in the output leads to further increases, and a decrease leads to further decreases. This can lead to exponential growth or decline, and can potentially result in a runaway effect if not balanced by other factors. Examples of positive feedback loops include the process of childbirth, where contractions lead to more contractions until the baby is born, and global warming, where increased temperatures lead to melting ice caps, which in turn leads to higher temperatures due to less sunlight being reflected back into space.

On the other hand, negative feedback loops are cycles that counteract or stabilise the effects of changes. They are self-correcting cycles where the output of a process inhibits the process itself. This means that an increase in the output leads to decreases, and a decrease leads to increases. This helps to maintain stability and equilibrium in a system by keeping variables within a certain range. Examples of negative feedback loops include the regulation of body temperature, where the body cools itself when it gets too hot and warms itself when it gets too cold, and the carbon cycle, where increased carbon dioxide levels lead to increased plant growth, which in turn reduces carbon dioxide levels.

In summary, while both positive and negative feedback loops are self-regulating cycles, they respond to changes in opposite ways. Positive feedback loops amplify changes, leading to growth or decline, while negative feedback loops counteract changes, maintaining stability and equilibrium.