China's Three Gorges Dam impacts Earth's rotation, study finds

China's Three Gorges Dam, the world's largest hydroelectric dam, opened in 2003 after nine years of construction costing £29 billion. It spans the Yangtze River and can power 5.4 million households monthly at full capacity. Recent studies show the dam's mass affects Earth's rotation, increasing the length of a day by 0.06 microseconds. This shift may complicate timekeeping for atomic clocks, prompting discussions about a potential negative leap second in the future. The dam required relocating 1.3 million people and has been praised for its engineering success. However, it has also faced criticism for flooding archaeological sites and increasing environmental risks, such as landslides.