Feedback Mechanisms, Tipping Points | AQA A-Level Environmental Science Revision | Primrose Kitten

Feedback mechanisms

Processes that contribute to climate regulation by either reversing or amplifying changes in the atmosphere.

Negative feedback mechanism

Works to reverse the original change, for example, increased cloud cover reflecting solar radiation to reduce temperature increase.

Positive feedback mechanism

Amplifies the original change, such as melting permafrost releasing methane, contributing to the greenhouse effect and further increasing temperatures.

Gaia hypothesis

A concept proposed by James Lovelock, identifying Earth as a living system regulating abiotic factors to maintain dynamic equilibrium.

Dynamic equilibrium

A stable state where opposing processes balance each other out.

Tipping points

Irreversible points where damage caused by human activities cannot be reversed, even if the activities stop.

Land ice melt

The melting of ice on land, contributing to the dilution of seawater and slowing of ocean currents.

Permafrost

Permanently frozen ground containing organic matter, the melting of which releases greenhouse gases like methane.

Albedo

A measure of surface reflectivity, with lower albedo leading to more heat absorption and further temperature increase.

Ocean currents

Continuous, directed movement of seawater, crucial for distribution of heat

Gulf Stream

A powerful warm ocean current that influences the climate of the east coast of North America and Western Europe.

Thermohaline circulation

Global density-driven circulation of seawater, influenced by temperature and salinity, affecting climate.

Corals

Marine invertebrates that build exoskeletons, affected by ocean acidity and crucial for carbon sequestration.

Carbon sequestration

The natural process of capturing and storing atmospheric carbon dioxide to mitigate global warming and climate change.

pH

A measure of the acidity or alkalinity of a solution, with lower pH indicating higher acidity.

Exsolving

The process of gas being released from a solution, such as carbon dioxide being released from ocean water into the atmosphere.