• There is evidence to suggest that there have been five distinct ice ages
  • This cycle, expectedly, requires enormous energy

Study by Milutin Milanković

  • Serbian scientist
  • Study done in early 1900s
  • Studied the earth’s position relative to other planets and came up with the theory of ice ages

Theory of ice ages

  • Gravitational pull of the sun and moon gently affect Earth’s motion and tilt toward the sun
  • During parts of this cycle, which can last tens of thousands of years, each of the Earth’s hemispheres gets a little more or a little less solar radiation than they’re used to
  • Milutin Milanković’s theory initially assumed that “the tilt” caused the ravenous winters

Addendum by Wladimir Köppen

  • Russian meteorologist
  • He dug deeper into Milutin’s work

What he found?

  • Moderately cool summers, not cold winters were the culprit
  • Begins when the summer never gets warm enough to melt previous winter’s snow
  • The leftover ice makes it easier for snow to accumulate the following winter
  • This increases the odds of snow sticking around in the following summer
  • Perpetual snow reflects more sunlight which makes things even cooler
  • A few hundred years a seasonal icepack grows into a continental ice sheet
  • The same thing happens in reverse; when orbital tilt lets in more sunlight
  • Slowly, temperatures increase

Sources