Climate change is influencing the length of the day, according to an analysis published in PNAS. As melting ice accelerates due to rising temperatures, sea levels rise and large masses move from the polar to the equatorial regions. This redistribution affects the Earth's rotation and results in longer days. During the 20th century, sea level variations were associated with changes in day length between 0.3 and 1 millisecond per century, but since 2000 this variation has increased to 1.33 (±0.03) milliseconds per century and the authors estimate that it will accelerate further in the coming decades.
Santiago Belda - duración días EN
Santiago Belda
Distinguished Researcher in the Geodesy and Spatial Dynamics Group of the Department of Applied Mathematics of the University of Alicante
Over millions of years, the Earth's rotation has slowed down mainly due to the frictional effects associated with the tides driven by the Moon. In addition to this, the mass movement of our atmosphere together with that of ocean currents have also played an important role in determining variations in the Earth's rotation, which is directly related to the length of the day as we know it today.
This study is a breakthrough because it confirms that the worrying loss of ice that both Greenland and Antarctica are suffering has a direct impact on the length of the day, causing our days to become longer. This has been rigorously demonstrated and quantified using a multitude of geodetic observations and models that attempt to reliably describe where the water from melting polar ice is moving to.
Curiously, this increase in the length of the day, caused by a decrease in the speed of the Earth's rotation, has been accentuated in recent years (from 2000 onwards) by the effects of climate change and greenhouse gases, where the melting is even greater due to the alarming increase in the temperature of our planet. This variation in the length of the day has critical repercussions not only on how we measure time, but also on GPS and other technologies that govern our modern lives.
- Research article
- Peer reviewed
Mostafa Kiani Shahvandi et al.
- Research article
- Peer reviewed
