Well, obviously! The earth is dynamic. But the idea that global warming – by the mechanism of unloading water from this place and putting it in another place – is triggering earthquakes is a bit of a flawed headline.
“Climate change may play a critical role in triggering certain faults in certain places where they could kill a hell of a lot of people,” says Professor McGuire. Some of his colleagues suspect the process may already have started.
It sounds like a pitch for a Hollywood apocalypse-fest – indeed the movie 2012 featured the Earth’s crust collapsing after a rapid heating of the Earth’s core. The mechanism here is rather more mundane, though potentially no less devastating.
Evidence from the end of the last Ice Age has already shown that the planet’s uneasy web of seismic faults – cracks in the crust like the one that runs along the Himalayas – are very sensitive to the small pressure changes brought by change in the climate. And a sensitive volcano or seismic faultline is a very dangerous one.
The disappearing ice, sea-level rise and floods already forecast for the 21st century are inevitable as the earth warms and weather patterns change – and they will shift the weight on the planet. Professor McGuire calls this process “waking the giant” – something that can be done with just a few gigatonnes of water in the right – or wrong – place.
This is somewhat like the fracking and wastewater disposal argument or the moon triggers quake idea. The faults are already there and activated by the additional activity. In this case of dynamic loading/unloading, the fault needs to be pretty much ready to go and the extra factor pushes it along. How much it accelerates the process is VERY unclear. So to say that climate change makes more “fatal” earthquakes is a bit of a stretch. As noted, the “Hollywood” aspect may be too good to pass up. Scientific understanding suffers.
Places like Nepal, the location of a devastating earthquake this week, will be seismically active and dangerous for all of human existence. We know this thanks to decades of documentation and we know the cause from the well-tested, very solid theory of plate tectonics.
You can, with certainty, predict that fatal catastrophes will occur in the future in distinct areas. We can also limit fatalities with upgrades to construction and better technology. So the best effort is to prepare, not scare.
See earthquakes around the world in the past 7 days here.