The Three Gorges Dam, the world’s largest hydroelectric power station, has sparked scientific debate about its potential impact on Earth’s rotation. While the changes are minuscule, they highlight how human activities can influence the planet’s spin, adding to the effects of natural disasters and climate change.
Earth’s perpetual rotation, like the daily sunrise and sunset, is a testament to its formation from a primordial cloud of gas and dust. This initial spin, preserved today, dictates the direction of Earth’s rotation. While most planets in our solar system spin counterclockwise like the sun, Venus and Uranus exhibit unique spins. Venus’ thick atmosphere and atmospheric tides have likely slowed its rotation, causing it to spin clockwise. Uranus, on the other hand, spins on its side, possibly due to a collision with a massive object or gravitational influence from a former moon.
New research suggests that the rotation of Earth is slowing down, possibly due to the effects of climate change. Earth’s rotation rate has been gradually accelerating since the last Ice Age, because of the melting of polar ice sheets. However, a new study in Nature finds that climate change is causing changes in the distribution of water mass around the globe, which is in turn affecting the planet’s rotation rate.The study found that the redistribution of water mass towards the equator is causing a slight braking effect on Earth’s spin. This is delaying the need for a negative leap second, which would have been required within just two years without climate change. The researchers suggest that this time could be used to develop new technologies to handle negative leap seconds or to eliminate the need for them altogether. The study’s findings have important implications for organizations relying on precise timekeeping.
