Science writer David Quammen, who predicted a coronavirus pandemic in his 2012 book Spillover, is now warning that bird flu (H5N1) could be the next global threat. With over 70 human cases, including a death in the U.S., the virus has spread to cows, chickens, and even wild animals like raccoons and dolphins.

Though human-to-human transmission hasn’t occurred, experts fear mutations could change that. Quammen compares each viral replication to a spin of a roulette wheel—billions happen daily across infected animals, increasing the odds of a dangerous mutation.

He blames factory farming, overconsumption, and ecosystem disruption for fueling virus emergence, urging stricter biosecurity and reduced reliance on industrial animal protein.

Quammen warns the next pandemic may not be inevitable, but it’s increasingly likely if current practices continue. His advice: consume less meat, consider family planning, and push for stronger climate and health measures to reduce future pandemic risks.