5. That cold was drawn into the interior of the country by a loop in a current called the jet stream that allowed Arctic air to spill southward. But an offsetting kink allowed unusually warm tropical air to settle over the West, large parts of Alaska and much of the Arctic.
6. Mr Mallaby’s 800-page book was published in October by Bloomsbury and Penguin Press, and was hailed as “exceptional” in an FT review. It came up against strong competition from five other shortlisted books tackling the world’s critical economic and management challenges — from the US productivity gap to persistent gender imbalances.