When human activities disrupt and unbalance ecosystems, such as by way of climate change and biodiversity loss, things go wrong.

Pandemics – the global spread of infectious diseases – seem to be making a comeback. In the Middle Ages we had the Black Death (plague), and after the first world war we had the Spanish flu. Tens of millions of people died from these diseases.

Then science began to get the upper hand, with vaccination eradicating smallpox, and polio nearly so. Antibiotics became available to treat bacterial infections, and more recently antivirals as well.

But in recent years and decades pandemics seem to be returning. In the 1980s we had HIV/AIDS, then several flu pandemics, SARS, and now COVID (no, COVID isn’t over).

So why is this happening, and is there anything we can do to avert future pandemics?