In this thought-provoking and beautifully written essay about geological and human memory, a paleoclimatologist writes about what the Earth knows, records, and forgets. She also contemplates her brother’s tragic trajectory and mental deterioration after a snowboarding accident, weaving in a personal narrative that makes the piece all the more powerful.

Earth records provide us with this information: Ice cores, tree rings, ocean sediments, stalactites and stalagmites in caves, growth rings in corals, tusks, and mollusks. These archives accrete memories on time periods varying from months to millions of years, allowing us to see a spectrum of Earth changes on various temporal and spatial scales—how biology, ocean, and ice respond to climate change in signature patterns, and the points at which those systems are pushed past thresholds.

As I watch the unfolding of extreme events across our planet, I find myself continuously relocated to that moment in the car with my brother. The sense of fracturing that ripples from a single shock event, even if the full extent of damage is yet to reveal itself.

Cheri has been an editor at Longreads since 2014. She's currently based in the San Francisco Bay Area.