Policy Documents

7 Theories of Climate Change

January 1, 2010

“At least seven theories of climate change enjoy some support in the scientific community. With the anthropogenic global warming theory now in disrepute, it is a good time to review the other six …”

This booklet identifies seven theories, anthropogenic global warming (AGW) plus six others that do not claim man-made emissions are a major cause of climate change. Each theory is plausible and sheds light on some aspects of climate change that were hidden or obscured by too great a focus on the AGW theory.

The six alternative theories are:

  • Bio-thermostat -- rising temperatures and levels of carbon dioxide (CO2) in the atmosphere trigger biological and chemical responses that have a cooling effect, like a natural thermostat.
  • Cloud formation and albedo -- changes in the formation and albedo of clouds create negative feedbacks that cancel out all or nearly all of the warming effect of higher levels of CO2.
  • Human forcings besides greenhouse gases -- mankind’s greatest influence on climate is not its greenhouse gas emissions, but its transformation of Earth’s surface by clearing forests, irrigating deserts, and building cities.
  • Ocean currents -- global temperature variations over the past century-and-a- half and particularly the past 30 years were due to the slow-down of the ocean’s Thermohaline Circulation (THC).
  • Planetary motion -- natural gravitational and magnetic oscillations of the solar system induced by the planet’s movement through space drive climate change.
  • Solar variability -- changes in the brightness of the sun cause changes in cloud formation, ocean currents, and wind that cause climate to change.