Famines mainly came from wars. People started to claim land and territories, all the greedy things men do and hunting grounds become off limits. There are variable reasons for famines. There were people at certain periods that lived well,like the nomad types that moved with the climates and seasons and knew where they would get their next meals. Humans have the gift of common sense (when used right)
800–1000 Severe drought killed millions of Maya people due to famine and thirst and initiated a cascade of internal collapses that destroyed their civilization.
1229–1232 The Kangi famine, possibly the worst famine in Japan's history. Caused by volcanic eruptions.
1601–1603 One of the worst famines in all of Russian history; famine killed as many as 100,000 in Moscow and up to one-third of Tsar Godunov's subjects. Same famine killed about half Estonian population. The famine was part of worldwide record cold winters and crop disruption, which in 2008 geologists linked to the 1600 volcanic eruption of Huaynaputina in Peru.
1630–1631 Deccan Famine of 1630–32. The famine was the result of three consecutive staple crop failures, leading to intense hunger, disease, and displacement in the region.
1661 Famine in India, due to lack of any rainfall for two years.
1695–1697 Great Famine of Estonia killed about a fifth of Estonian and Livonian population (70,000–75,000 people). Famine also hit Sweden (80,000–100,000 dead). The climate was unfavorable for crops in 1694 and the summer of 1695 was cold and rainy, followed by an early autumn frost that destroyed the summer crops. Cold conditions continued during 1696, and rain fell throughout the summer. Peasants, orphans and the elderly began to die en masse of starvation and the spring snow-melt of 1697 revealed many corpses. Meanwhile, landlords and merchants exported grain to Finland and Sweden, where crops also had failed.
1783 Famine in Iceland caused by Laki eruption killed one-fifth of Iceland's population.
1789–92 Doji bara famine or Skull famine. Brought on by a major El Niño event lasting from 1789 CE to 1795 CE and producing prolonged droughts. Recorded by William Roxburgh, a surgeon with the British East India Company, in a series of pioneering meteorological observations, the El Niño event caused the failure of the South Asian monsoon for four consecutive years starting in 1789.
1816–1817 Year Without a Summer. Severe climate abnormalities caused average global temperatures to decrease by 0.4–0.7 °C (0.7–1.3 °F). This resulted in major food shortages across the Northern Hemisphere.