POLICY-MAKERS have been much occupied with so-called 鈥渂lack swans鈥� 鈥� rare, disruptive events that lie well beyond normal expectations. Is the current air-travel pandemonium across Europe such a bird (see 鈥淏lame the volcano trouble on sun and global warming 鈥�)?
No. We鈥檝e long known that Iceland has active volcanoes and that ash and jet engines don鈥檛 mix. It seems we need a term for big, obvious threats that are sure to emerge 鈥� think asteroid impacts 鈥� but which few want to face. Handily, students of 鈥溾�� have already coined one: 鈥渂lack elephants鈥�.