'I’m walking to Mrs Macquarie’s Chair in Sydney’s Domain at high tide, scanning the small bay in Woolloomooloo, as I always do, for fish or stingrays. There’s nothing to see in the flat green water nudging the sandstone cliffs of the tiny beach, or below the sea wall; I can’t even spot the usual mullet nosing around the floating walkways at the marina. A few years ago, I might have assumed the variation in numbers was seasonal, hoping for better luck next time. But since 2016, when the figures started to come through that we have lost around 60 per cent of the world’s wildlife over the last half-century—not only exotic animals but common creatures like giraffes, sparrows, and even insects—it’s hard not to see today’s emptiness as a sign of catastrophic absence.' (Introduction)