“Ecosystems are complex networks. They can be remarkably resilient under stress, but when certain key nodes begin to fail, knock-on effects reverberate through the web of life. This is how mass extinction events unfolded in the past. It’s not the external shock that does it – the meteor or the volcano: it’s the cascade of internal failures that follows. It can be difficult to predict how this kind of thing plays out. Things like tipping points and feedback loops make everything much riskier than it otherwise might be. This is what makes climate breakdown so concerning.”