Nearly any time a major natural disaster strikes — an earthquake in Japan, an eruption in Chile — someone tries to link it to climate change.
Usually such claims are bunk. But McGuire, a geologist at University College London, shows that there can be an underlying grain of truth. What happens in the atmosphere, it turns out, doesn’t stay in the atmosphere. Climate change can in fact affect the solid Earth and its natural hazards.
Consider the end of the last ice age, some 12,000 years ago. Changes in Earth’s orbit, along with rising atmospheric levels of carbon dioxide, conspired to melt great glacial masses. As the ice melted, huge landscapes were suddenly relieved of their overlying burden. The ground rebounded, and stresses shifted within the crust. The result: more earthquakes in Scandinavia and more volcanic eruptions in Iceland.
Today Earth is in the midst of similar kinds of changes. Greenhouse gases spew from power plants, the atmosphere is heating up and ice is melting (though at a far smaller scale, at least so far). Places like Alaska may serve as the proverbial canary in the coal mine, where melting ice leads to more quakes and who knows what else.
McGuire lays out a strong case for the interconnectedness of Earth systems, showing for instance how the destabilization of seafloor methane may cause huge underwater landslides and tsunamis. Yet when it comes to the most crucial question, of how future climate change will affect the planet, even he cannot say. Science is providing scary hints about how fast Earth is changing, but it cannot predict exactly what will transpire.
Anyone looking for a guide to the future may need to simply wait until it is here.
Oxford Univ., 2012, 320 p., $29.95