Mao Zedong’s ‘Four Pests’ campaign

Mao Zedong’s ‘Four Pests’ campaign in 1958 caused the near-extinction of the Eurasian Tree Sparrow which, in turn, contributed to 20m+ deaths in the Great Chinese Famine.

Mao thought the sparrows were eating grain and rice. What he didn’t realise was that they also ate the insects that devoured the crops.
Complex systems are complex. We’re not separate from the natural systems we live inside.