As first established by the Serbian mathematician Milankovitch, and appropriately bearing his name, the distribution of radiation at the Earth's surface, and hence climate, cycles in sympathy with fluctuations in the tilt of the Earth's axis as it passes in its orbit around the sun.
(it; passes; L:in its orbit around the sun) (Milankovitch; [is] mathematician [from]; Serbia)
it Milankovitch
passes [is] mathematician [from]
L:in its orbit around the sun
Serbia