kalpa of decrease ［減劫］ ( gen-kō): A period in which the human life span is said to diminish. In the kalpa of continuance—the second of the four kalpas of formation, continuance, decline, and disintegration that a world undergoes—the human life span repeats a cycle of change, decreasing by a factor of one year every 100 years until it reaches 10 years, and then increasing at the same rate until it reaches 80,000 years. Then it begins to decrease again until it reaches 10 years, and so on. This pattern of decrease and increase is said to occur repeatedly in the kalpa of continuance. Any period of diminution is called a kalpa of decrease. Any of the periods in which the human life span is increasing is called a kalpa of increase. It is said that Shakyamuni appeared in the present kalpa of continuance, in the ninth kalpa of decrease, when the life span of human beings was a hundred years long. See also kalpa.