The Earth fights back

Never mind higher temperatures, climate change has a few nastier surprises in store. Bill McGuire says we can also expect more earthquakes, volcanoes, landslides and tsunamis

Unlike most apparently intractable problems, which have a tendency to go away when examined closely and analytically, the climate change predicament just seems to get bigger and scarier the more we learn about it.

Now we discover that not only are the oceans and the atmosphere conspiring against us, bringing baking temperatures, more powerful storms, floods and ever-climbing sea levels, but the crust beneath our feet seems likely to join in too.

Looking back to other periods in our planet’s history when the climate was swinging about wildly, most notably during the last ice age, it appears that far more than the weather was affected. The solid earth also became restless, with an increase in volcanic activity, earthquakes, giant submarine landslides and tsunamis. At the rate climate change is accelerating, there is every prospect that we will see a similar response from the planet, heralding not just a warmer future but also a fiery one.

Several times in the past couple of million years the ice left its polar fastnesses
and headed towards the equator, covering much of the world’s continents in ice sheets over a kilometre thick, and sucking water from the oceans in order to do so. As a consequence, at times when the ice was most dominant, global sea levels were as much as 130m lower than they are today; sufficient to expose land bridges between the UK and the continent and Alaska and Russia.

Each time the ice retreated, sea levels shot up again, sometimes at rates as high as several metres a century. In the mid 1990s, as part of a study funded by the European Union, we discovered that in the Mediterranean region there was a close correlation between how quickly sea levels went up and down during the last ice age and the level of explosive activity at volcanoes in Italy and Greece.

Guardian