Climate System and Forcing

Climate System

The parts of Earth that interact to control climate

Five Main Climate Components

Atmosphere, oceans, ice, land, and biosphere

Climate Forcing

Something that causes Earth's climate to change

External Forcing

A cause of climate change from outside the climate system

Internal Climate Forcing

Climate changes caused by interactions between Earth's systems

Plate Tectonics

Movement of Earth's plates that changes mountains, oceans, and volcanic activity

Plate Tectonics Timescale

Usually affects climate over millions of years

Earth's Orbit

Changes in Earth's movement around the Sun that affect solar energy

Solar Strength

The amount of energy Earth receives from the Sun

Sunspots

Changes in solar activity that can affect solar energy

Solar Radiation

Energy from the Sun that heats Earth

Earth's Albedo

The amount of sunlight reflected back into space

Average Earth Albedo

About 30% of incoming sunlight is reflected

Response Time

How long a climate component takes to react to a change

Fast Climate Response

Atmosphere can respond within hours to weeks

Slow Climate Response

Deep oceans and ice sheets can take hundreds to thousands of years

Positive Feedback

A process that makes an original climate change stronger

Negative Feedback

A process that reduces an original climate change

Ice-Albedo Positive Feedback

Warming melts ice, exposing darker surfaces that absorb more heat

Water Vapor Positive Feedback

Warming adds water vapor, which traps more heat

Negative Feedback Example

More heat escaping to space as Earth warms can reduce warming