In Climate Crash, by John Cox, there is no debate about the scale of rapid climate change, just the facts about how it was discovered and theories on what triggers it. But one thing's definite: abrupt climate change is nothing new.

Since a chance discovery in 1930 that climate history is recorded in Greenland's ice cap, scientists have analysed ice cores to plot global mean temperature for the past 100,000 years.

The amplitude is startling, with swings of up to 28°C, but it's the volatility that is terrifying. When Earth's climate shifted from the freezing and dry Young Dryas period to the present mild and wet Holocene period about 12,000 years ago, the temperature in Greenland increased about 19°C in less than 20 years – possibly 10.

Cox's book is fascinating and he has a knack for clarity, from describing the engineering challenge of extracting a three-kilometre-long ice core, to explaining how salinity levels can affect ocean currents. However he has troubles with theorists' and mathematical modellers' attempts to explain rapid climate change: so far, computer models have not matched historical climate extremes.

But what we all want to know is: will the CO₂ produced since the industrial age cause Earth's climate to suddenly lunge towards a new and uncomfortable equilibrium? All Cox offers on that point is that air bubbles from polar ice have shown the atmosphere during the last Ice Age had a third less CO₂ than today.

But then, rapid climate change could also be caused by Earth's changing orbit, volcanic activity, ice surges and the Sun as well as anthropogenic sources. The point is, scientists are still unsure how all the parts that contribute to rapid change interact. Maybe we have to live with that for a while.

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