Lengthening Earth days: Climate change slows rotation by milliseconds
Increasing temperatures accelerate the melting of glaciers and ice caps, directly resulting in a rise in sea levels. As Earth's ice cover thins, it heats up faster. However, this is not the end of the consequences brought about by climate change. Because of this, our days are getting longer.
Scientists from the Swiss Federal Institute of Technology in Zurich and NASA's Jet Propulsion Laboratory have examined the problem. According to them, as ice masses melt, more mass is transported from the poles to the equator, slowing down our planet's rotation around its axis.
It’s like when a figure skater does a pirouette, first holding her arms close to her body and then stretching them out. The initially fast rotation becomes slower because the masses move away from the axis of rotation, increasing physical inertia. In physics, we speak of the law of conservation of angular momentum, and this same law also governs the Earth’s rotation – explains Dr. Benedikt Soja from ETH Zurich, co-author of the study, as quoted by "National Geographic".
Over the years, the shape of Earth also changes. This is influenced by ocean tides, the drift of tectonic plates, as well as sudden earthquakes and volcanic eruptions.
Scientists have used GPS data, cosmic radio signals, and even ancient records of solar and lunar eclipses to assess the rate at which Earth rotates around its axis best.
The result? From 1900 to today, climate change has lengthened days by about 0.8 milliseconds. If greenhouse gas emissions do not change by 2100, it will lead to an extension of days by 2.2 milliseconds compared to the baseline level.
Lengthening of Earth's day. Milliseconds make a big difference
Contrary to appearances, every millisecond has enormous significance – especially from the perspective of space. It affects GPS systems, is significant for rocket launches and the determination of the trajectories of probes they launch.
It is also very important for us on Earth to know that the slower our planet rotates, the greater the likelihood of major earthquakes.
