The Covid-19 pandemic represents a tragedy for its victims and their families, and economic hardship for the rest of us. As I write these lines in Los Angeles, 10 weeks after the state of California imposed a lockdown, some shops are reopening and a semblance of normal life is beginning to return.

But the costs have been great: in my case, the past month has brought the deaths of five friends, two of them among my longest relationships. Against that background, it seems vile to say anything ‘positive’ about Covid-19. Paradoxically, though, the pandemic might also bring hope and permanent benefits for the whole world – depending on how we react.

Microbes have often shaped human history. Thousands of years before the Black Death, a previous spread of plague may have contributed to the intrusion of Asian steppe peoples carrying Indo-European languages into Europe. Later, far more Native Americans – including the Aztec emperor Cuitláhuac and the Inca emperor Huayna Capac – died in bed from European germs than on the battlefield from European swords and guns.

Those epidemics of the past had far-reaching harmful consequences: military defeats, population crashes, abandonments of land under cultivation and slumps in trade. They also resulted in conquests and replacements of populations, when previously unexposed peoples contracted diseases from invaders with a long history of exposure.

At the time of writing, official counts are approaching 350,000 deaths globally from Covid-19; the true figure is likely to be higher1. Steep death tolls are still to come in populous countries such as Brazil and Mexico, aided by policies of denial on the part of those countries’ presidents.

Yet Covid-19 doesn't represent an existential threat to the survival of our species. Yes, the pandemic will be a serious blow to the world's economy, but that will recover; it's only a matter of time. Unlike many of the epidemics of the past, the virus isn't threatening to cause military defeats, population replacements or crashes, or abandonments of land under cultivation.

There are other dangers, present right now, that do constitute existential threats capable of wiping out our species, or permanently damaging our economy and standard of living. But they are less convincing at motivating us than is Covid-19, because (with one exception) they don't kill us visibly and quickly.