I’m kind of surprised that no one has mentioned this one yet:
Science Rules - Host Bill Nye the Science Guy!
Also, for survival in general:
The Survivalist Preppers Podcast
Stuff You Should Know (general information that people should know about)
Blackout (it’s a drama story about America going without electricity - does have explicit language though) - I’ve listened to the first episode (it’s pretty good).
Also, the Chernobyl Podcast for the mini-series on HBO.
13 Minutes to the Moon - BBC World Science (About the Apollo missions).
All of these should be on iTunes and any other podcasts service.
Several fascinating episodes on This Is Love. Yellowstone Wolves. Aggressive bison near SLC. Love of nature and Prairie Warblers. Must listen.
Cryptinaturalist. Zany monologues featuring a variety of cryptids. I can barely tell what is going on but it’s hilarious.
I second Off Track @oneanttofew! Some of the best around. If you don’t listen to the underwater acoustic episode and then run out and buy an underwater microphone, I don’t even know what.
Common Land. Creation stories of protected landscapes.
Brain On Nature. If you like Florence Williams, you’ll like this. Brain injury. Nature. Great audio production.
The Wild. On location nature stories from around the world.
I just started a new podcast with fellow naturalist, Glenn Etter called The Single Acorn. Each season focuses on a broad natural history topic (currently: Symbiosis, next up: Scat), with each episode digging into a topic within the category (currently predator/prey relationships).
I enjoy Tristan Gooley’s The Pursuit of Outdoor Clues; each episode is usually about 40 minutes in length and the listener accompanies him on a walk through the English countryside - learning about animals, tracking & navigational clues in nature.
It can be found on the usual platforms, including Apple, Spotify, Stitcher etc.
It isn’t strictly a podcast but Ray Brown’s Talkin’ Birds is cool. I was a guest on an episode a few weeks ago talking about my volunteer work as an eBird reviewer.
I’ve really been enjoying the Nature Guys podcast that’s already been mentioned. What I like is that they’re from the midwest US and each episode usually focuses on one of the plants or animals that are easily seen in the area. It’s not about travelling the globe in search of rare species.
Several of the gardening podcasts are also good for us “backyard naturalists”. Many focus on organic gardening techniques and have episodes on native plants, creating habitat, birdwatching, protecting the soil food web, etc. They’ll often do interviews with people like Doug Tallamy who’s an entomologist that writes books about creating or preserving wildlife habitat at your home. Two of the gardening podcasts I like are A Way to Garden and The Joe Gardener Show.