Climate Change Slows Earth’s Spin

Climate Change Affects Earth’s Rotation

A recent study has discovered that climate change is causing the Earth's rotation to slow down, making days slightly longer. The research, published in the Proceedings of the National Academy of Sciences, highlights how rising sea levels and melting polar ice caps are contributing to this phenomenon.

As polar ice caps melt, water is redistributed from the poles to the equator, making the Earth more oblate or "fatter." This shift in mass causes a decrease in the planet's rotational speed, effectively lengthening the duration of each day. Since 1900, this has significantly increased, adding a few milliseconds to the 24-hour day.

The study's authors emphasize that while the added milliseconds may seem minor, they have important implications for precise timekeeping and space navigation. The pace of this change is unprecedented, outpacing any similar changes seen during the 20th century.

If greenhouse gas emissions continue unabated, the study projects that the length of the day could increase by an extra 2.62 milliseconds per century by the end of the 21st century. This would make climate change a more significant factor in long-term variations in day length than lunar tides.

The findings are part of a broader body of research investigating the impacts of climate change on global timekeeping. Earlier research published in Nature found that rapid polar ice melt could further slow the Earth's rotation, potentially influencing our methods of measuring time.

Coordinated Universal Time (UTC), the global standard for time measurement, relies on about 450 atomic clocks worldwide. To maintain alignment with Earth's rotation, a leap second is occasionally added to UTC. The study's author, Professor Duncan Agnew from the Scripps Institution of Oceanography, compared the effect to a skater spinning: extending their arms slows them down, while bringing them in speeds them up.

As the climate crisis progresses, understanding these changes becomes increasingly important for managing timekeeping and navigation systems, further illustrating the extensive impact of climate change on our planet.