Climate change is changing the planet. Yes, it’s doing it in all those ways that you already know about: rising seas, rising temperatures, changing rainfall patterns, more extreme weather. But climate change is changing the planet in another dramatic way, too: It’s actually causing the entire crust of the Earth to shift. According to new research by Jianli Chen and colleagues, climate change–induced glacier melt and sea level rise have thrown the whole planet off-kilter.
The Earth is a ball that floats in space, and the Earth’s surface—the tectonic plates that make up the land—are like a shell that floats on the mantle below. Just like the hard chocolate coating can slip and slide on your soft serve ice cream, the crust of the Earth can slide over the mantle. This is different than continental drift. This is the whole surface of the planet moving as one. The rotation axis of the Earth stays steady, the land masses shift around it. The idea is known as “true polar wander,” and its occurrence is a part of the planet’s history.
The Earth is not a perfect sphere—it’s kind of fat at the middle—and changing how the mass on the surface is distributed changes how the tectonic plates sit in relation to the planet’s rotation axis. By melting Greenland and other glaciers, say the researchers, the Earth’s geographic North Pole has drifted to the east at around 2.4 inches each year since 2005. Nature:
From 1982 to 2005, the pole drifted southeast towards northern Labrador, Canada, at a rate of about 2 milliarcseconds — or roughly 6 centimetres — per year. But in 2005, the pole changed course and began galloping east towards Greenland at a rate of more than 7 milliarcseconds per year.
Seasonal shifts in how ice and water are spread around the world mean that the North Pole is always sort of wandering around. But drift triggered by climate change is new. It’s a sign that global warming isn’t just changing how we might live in the world, but the very face of the world itself.