Recently, at an event in London, I had the good fortune of meeting with some members of the Open Air Laboratory (OPAL). They were demonstrating one of their citizen science projects, the Tree Health Survey. Our trees are under threat from an increase in attacks by pests and diseases, and OPAL in collaboration with Forest Research and FERA have decided to fight back by enabling you to go out and record any sign of danger for the trees in your local area. To take part, visit their site and download the survey pack now!