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CLIMATE CHANGE: The Causes of 20th Century Warming
Science (New York, N.Y.)
|August 31, 2007
Summary
Global temperatures rose unevenly in the 20th century, with distinct warming periods. Human activities, influenced by solar and volcanic factors, are the primary drivers of this observed climate change.
Area of Science:
- Climate science
- Atmospheric physics
- Environmental science
Background:
- 20th-century global air surface temperatures showed a significant increase of approximately 0.6 degrees C.
- This warming trend was not continuous, exhibiting distinct periods of warming and cooling.
Purpose of the Study:
- To analyze the patterns of 20th-century climate change.
- To investigate the primary drivers of observed temperature variations.
Main Methods:
- Comprehensive climate simulations of the 20th century were performed.
- Observed temperature variations were compared with simulated results.
Main Results:
- Two distinct warming periods were identified: 1910–1945 and post-1976.
- A period of gradual cooling occurred between these warming phases.
- Simulated climate variations closely matched observed temperature trends.
Conclusions:
- Anthropogenic activities are the main drivers of 20th-century climate change.
- Variations in solar and volcanic forcing play a moderating role in climate change.
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