Climate change

Introduction
The Earth system
Evidence for climate change
Causes of climate change
- Solar variability
- Volcanic activity
- Tectonic activity
- Orbital (Milankovich) variations
- Greenhouse gases
- Feedback
- Human activities
Climate change within a human life span
- Seasonal variation
- Interannual variation
- Decadal variation
Climate change since the emergence of civilization
- Centennial-scale variation
- Millennial and multimillennial variation
  - Thermal maxima
  - ENSO variation in the Holocene
  - Amplification of the Indian Ocean monsoon
Climate change since the advent of humans
- Recent glacial and interglacial periods
  - The most recent glacial phase
  - The Last Glacial Maximum
  - The last deglaciation
  - Climate change and the emergence of agriculture
- Glacial and interglacial cycles of the Pleistocene
- The last great cooling
Climate change through geologic time
- Cenozoic climates
- Phanerozoic climates
- Climates of early Earth
  - Faint young Sun paradox
  - Photosynthesis and atmospheric chemistry
  - Snowball Earth hypothesis
Abrupt climate changes in Earth history

References & Edit History Quick Facts & Related Topics

Images, Videos & Interactives

The Problem with Climate Change Explained by Bill McKibben

Infographic showing a timeline of major climate change milestones from 1896 to 2025, with key events listed on the left. Insets on the right display a graph of rising atmospheric carbon dioxide levels, diagrams of ocean acidification due to carbon dioxide, and a world map highlighting countries that have signed or ratified the Paris Agreement.

Close-up of pink cherry blossoms blooming on a tree branch against a blue sky with clouds, illustrating early spring caused by climate change.

The impact of human activities on climate change

Diagram showing Earth's axis of rotation tilted at about 23.5 degrees, illustrating precession as the axis traces a circular path over 26,000 years, shifting alignment from Polaris, the current North Star, to Vega. Labels indicate the plane of Earth's orbit and the changing orientation of the axis over time.

At a Glance

Combination shot of Grinnell Glacier taken from the summit of Mount Gould, Glacier National Park, Montana in the years 1938, 1981, 1998 and 2006.

Pop Quiz: 18 Things to Know About Global Warming

Climate change

climatology

Also known as: climate variation, climatic change, climatic fluctuation, climatic variation(Show More)

Written by

Stephen T. Jackson

Fact-checked by

Britannica Editors

Last updated

Nov. 12, 2026 •History

Climate change, periodic modification of Earth’s climate brought about as a result of changes in the atmosphere as well as interactions between the atmosphere and various other geologic, chemical, biological, and geographic factors within the Earth system. The atmosphere is a dynamic fluid that is continually in motion. Both its physical properties and its rate and direction of motion are influenced by a variety of factors, including solar radiation, the geographic position of continents, ocean...

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