Climate Change Disrupts Time, Scientists Discover
Climate Change’s Impact on Earth’s Rotation and Time
New research reveals that human-caused climate change is altering the speed of Earth’s rotation, thus changing the length of each day. This phenomenon, driven by polar ice melt due to global warming, was published in the Proceedings of the National Academy of Sciences.
Earth’s Rotation and Day Length
The Earth’s rotation speed dictates the length of a day, influenced by factors like the planet’s fluid core, the aftermath of the last ice age, and polar ice melt from climate change. Historically, the moon’s gravitational pull has slowed Earth’s rotation, increasing day length by a few milliseconds per century.
Climate Change’s Growing Influence
Surendra Adhikari from NASA’s Jet Propulsion Laboratory stated, “This is a testament to the gravity of ongoing climate change.” The study found that while the moon has been the dominant influence on day length, climate change could soon overtake this role. Benedikt Soja, a study author from ETH Zurich, emphasized that climate change might become the dominant factor if greenhouse gas emissions continue.
The Mechanism
As global temperatures rise, glaciers and ice sheets melt, causing meltwater to flow towards the equator. This redistribution of mass changes Earth’s shape, flattening the poles and bulging the equator, which slows rotation. This effect is comparable to an ice skater slowing down when extending their arms.
Historical and Future Trends
The team analyzed data from 1900 to 2100 using observational data and climate models. They discovered that climate change has significantly increased the length of a day. In the 20th century, climate change caused daily variations between 0.3 and 1 millisecond. Over the past two decades, this increase reached 1.33 milliseconds per century. If emissions continue unchecked, the day could lengthen by 2.62 milliseconds by the end of the century, surpassing the moon’s influence.
Technological Implications
Although the change is minuscule, it significantly impacts technology. Precise timekeeping is crucial for systems like GPS, which rely on atomic clocks. To keep time aligned with Earth’s rotation, “leap seconds” are occasionally added or subtracted from Coordinated Universal Time (UTC).
Speculations and Further Research
Mostafa Kiani Shahvandi from ETH Zurich noted a possible link between longer days and increased earthquakes, but this remains speculative. Duncan Agnew from UC San Diego acknowledged that while Earth’s core processes may also affect day length, climate change’s impact is more significant.
Jacqueline McCleary from Northeastern University highlighted the study’s contribution to understanding climate change’s role in altering day length. ETH Zurich’s Soja concluded, “We have to consider that we are now influencing Earth’s orientation in space so much that we are dominating effects that have been in action for billions of years.”
This research underscores the profound and far-reaching impacts of human activity on our planet.
Re-reported from the article originally published in CNN.
