Climate cycles Models Changes Commentary

Milutin Milanković atmospheric_sciences

Climate cycles

• The Earth’s position relative to the Sun
• changes in a complex rhythm,
• influenced by gravity of the Moon, the Sun,
• Jupiter, and Saturn.
• Milutin Milanković studied
• how Earth’s orbital eccentricity,
• its obliquity, and its axial precession
• influenced climate.
• The earth orbits
• in an imperfect circle
• that becomes more elliptical
• and then more circular
• every 100,000 years.
• It spins on a tilted axis
• that describes a loop
• every 26,000 years.
• The angle between the equatorial
• and orbital planes varies
• by 2.4 degrees
• every 41,000 years.
• Milutin Milanković showed
• that the combination of these cycles
• governed variations of sunlight on Earth,
• explained the ice ages,
• and could be used to predict
• future long-term climate changes.

Models

• Milanković made mathematical models
• to predict the climate on Earth—
• any where and any time.
• He modeled temperatures
• of the earth’s atmosphere
• at high altitudes.
• He modeled the climates
• of the Moon and other planets—
• Mars, Venus, and Mercury.
• His worked echoed what Newton had done
• for celestial mechanics
• and helped the transformation
• of descriptive sciences
• into exact ones.

Changes

• The climate changes without
• human intervention.
• For a scientist, the causes,
• for a poet, the effects
• are difficult to attribute,
• but the beauty is in the relation—
• how the perfection of the machine
• is rediscovered in its obliquity,
• how the icicle catches
• the bright light of morning.