Volcanoes can affect our climate, but can our rapidly changing climate trigger volcanic eruptions and destabilize the Earth’s crust?
McGuire (Geophysical and Climate Hazards/University College London; Global Catastrophes: A Very Short Introduction, 2009, etc.) looks back through geologic time to find correlations between climate change and the frequency of geophysical hazards such as volcanic eruptions, earthquakes, landslides and tsunamis. After tracking millions of years of geologic history, McGuire outlines how volcanic eruptions and collapses are stimulated by the disappearance of large ice sheets. The ice contained in glaciers redistributes water and its weight throughout the planet, affecting sea level, crust stability and even day length. Isostatic rebound—the Earth “bouncing back” after being buried beneath kilometers of ice—can induce earthquakes in unstable zones. Rising temperatures often translate into increased rainfall, which in turn can increase the incidence of landslides. McGuire’s explanations are dense but mostly conversational, and his examples are clear and easy to follow. He also offers understandable comparisons—e.g., ocean levels being lower by “a whisker less than the height of the London Eye Ferris wheel” during the last glaciation. Though the author notes that any change in climate contributing to the recent intense quakes and tsunamis “seems unlikely in the extreme,” he predicts that we will experience more geophysical hazards as sea levels continue to rise.
McGuire lays a strong foundation for thinking about the impact of global warming on the stability of the Earth’s crust.