Shifting baselines

How right Mark Carwardine is about “generational blindness to environmental destruction” (My way of thinking, November 2018). And it’s not just in relation to animals and insects – the forests and woods of my youth were generally free of the brambles that spread from the mid-1980s, and now blanket many in the east of England. When I mentioned this to a young forestry professional, I was met with astonishment: “So what was there?” Memory says grasses and a wealth of other plant life that has been displaced, adversely affecting other wildlife, I suspect. David Olivant, via email

I am indebted to Mark Carwardine for introducing me to the phrase ‘Shifting Baseline Syndrome’ (My way of thinking, November 2018), which reminded me of a conversation with an elderly man, about 30 years ago. He told me about standing on the Gower clifftops as a youngster, watching the sea darken from enormous shoals of mackerel – a sight that I have never seen, having grown up during a time of greater levels of industrial fishing pressure.

Mark says that continuous measurement is necessary to provide accurate baselines, but as these have already shifted, perhaps we should collect the memories of our older generations, to record what they regarded as the norm. Stephen Davies, via email