British Sign Language Glossaries of Curriculum Terms

BSL Environmental Science Glossary - Positive feedback mechanism definition

Definition: A process where an action has consequences which affect the original process and positive feedback mechanism will increase the rate of the original action. This will result in a change that cannot easily be reversed. The natural world has processes that enable balances to be maintained but human activity has resulted in changes that cannot easily be reversed. For example, acidification which occurs when more and more CO₂ is absorbed by sea water and changes the pH (making it more acidic) - this affects marine life and has destroyed coral reefs. Another example is the melting of polar ice caps which means that less sunlight/heat is reflected and results in a rise in temperature that cannot easily be reversed.