Mark L. Hineline

One warm afternoon, when I was about twelve years old, I went walking by myself in a grove of Sequoias in the national park that was named for those grand trees. My family was camped nearby; they were accustomed to my solitary walks and would not have been alarmed. Every dozen yards I would pause and stare up at the canopy far above my head, and then I would continue on my way.

I came to a swiftly flowing stream and began to hop, stone to stone, across it. About midway on what was in fact a very short journey I stepped on a mossy boulder, slipped, and fell into the stream. I grasped and kicked at rocks as I was swept downstream; nothing I did stopped my slide through the mountain water. And then I went over a waterfall. I fell, perhaps, twenty feet.

I remember thinking: this could be it. I might die. I remember the plunge into a deep pool of water, and the way I bobbed to the surface, very much alive.

Since then, I've learned about stream erosion and waterfalls. What happened to me that day wasn't the only possible outcome, but it wasn't unlikely either; some waterfalls descend to plunge pools, while others hammer away at rocks at or near the surface below the fall.

I was lucky, that's all. Lucky in the same way that I was lucky to be in the Sierra at all, or to have backpacked to over 10,000 feet the year before, when I was eleven. I've been lucky to live in wonderful parts of the United States - on the coast of Maine, near the beaches of San Diego, in the Western Reserve of Connecticut (better known as northeastern Ohio), on the southern edge of the Colorado Plateau, and in my current home in Lansing, Michigan.

Each of these has its own natural identity: different climates, rocks, birds, plants, and culture. I am making it my business to write about them, and about what is happening to them as they are transformed by climate change. On that last point, I'm not so blithe. But nature is nature, changing or not.

I studied American philosophy and geology in Maine; and the history, philosophy, and sociology of science in San Diego. I've taught there, at UC San Diego, and here, at Lyman Briggs College at Michigan State University. I've gotten better at grabbing onto a rock here and there, as life gives me surprises - grabbing on, pulling myself out of the stream, shaking off as best I can, and peering over the waterfall to see what awaited me.

And then writing about the journey.