Bacteria are Earth’s most ancient creatures.

And there are lots of them, with a total mass a thousand times more than all humans.

Microbes — both prokaryotic and eukaryotic — make planet Earth go round. Some of them are dangerous pathogens. Most of them aren’t. Indeed, some bacteria are great kitchen companions.

Anna Sigrithur has been harnessing microbial magic, fermenting food and drinks for years. She’s also a writer and artist, focusing on food cultures, food preservation, fermentation, microbiology, sensory perception and human/non-human relationships.

Listen to our conversation in today’s GPM podcast. Click on the play button above, or go here.

Ferments in process

Since the dawn of civilization, nothing has fascinated humans more than the diversity of life around them. Aristotle was among the first natural historians. Naturalis Historia, by Pliny, is the Roman Empire’s largest surviving work. The collection, description and preservation of living things has come a long way since then. Today, biologists use fancy tools to collect creatures, and DNA barcoding technology to identify them.

Here’s a story about DNA barcoding. Click on the play button above, or go here.

Dutch barcoder Kevin Beentjes and his barcode reader (David Kattenburg)

Earth’ surface is a little over one degree warmer today, on average, than it was at the start of the industrial revolution 200 years ago.

That doesn’t seem like much. Under the Paris Agreement, governments agreed to limit temperature rise to two degrees. At present emission rates, that target will likely be exceeded.

In a landmark report published in the prestigious Proceedings of the National Academy of Scientists, back in 2018, researchers warned that a two degree rise in global surface temperature may actually exceed a critical planetary threshold, pushing Earth down a cascade of tipping points into “hothouse” mode, unlike anything this third rock from the sun has experienced since the mid-Miocene epoch, fifteen million years ago.

The GPM spoke about the report with its lead author, Will Steffen. A native of Norfolk, Nebraska, Steffen emigrated to Australia in the 1970s, where he took up a position at the Australian National University in Canberra. He served as the Executive Director of the International Geosphere–Biosphere Programme, a ground-breaking initiative aimed at studying the chemical, physical and biological processes governing Earth as system. His name came to be associated with a host of ideas about our planet, and humanity’s fate. Steffen’s Great Acceleration curves helped corroborate the idea, first proposed by Dutch chemist Paul Crützen, that Earth has entered a new Epoch, the Anthropocene.

Will Steffen passed away in January 2023.

Listen to our conversation in today’s GPM podcast. Click on the play button above, or go here.