Whilst rummaging through some of the UK's dusty Risk & Regulation Advisory Council archives, we strayed across 'A Worrier's Guide to Risk'. David Spiegelhalter (Chair of the Winton Centre for Risk and Evidence Communication at the University of Cambridge) put it together for them in the noughties.

It's a great guide to thinking about risk, some of which applies to trees, on one side of paper - our favourite length for a subject.