4 ideas
Across cultures and millennia, humans have used the underground for three recurring purposes: to shelter what is precious (the dead, sacred art, memories), to yield what is valuable (ore, fuel, water, knowledge), and to dispose of what is harmful (waste, poison, secrets). Asking which of the three a given descent serves shows why the same subterranean space can be tomb, mine, and dump at once, and why our relation to the underland is so ambivalent.
At Olkiluoto in Finland, Macfarlane descends into Onkalo, a repository cut roughly 400–450 metres into ancient bedrock. It is designed to hold spent nuclear fuel in copper canisters packed in bentonite clay and then seal it for about 100,000 years, longer than any human institution or language has lasted. Its designers face an unresolved dilemma: mark the site with warnings that future beings may misread as an invitation to dig, or leave it unmarked and trust forgetting to protect them.
Thinking in geological spans of millions of years usually seems to shrink human concerns. Here it is used the other way, as a moral instrument that makes our present actions visible as long-lasting legacies. Reframing each decision as "are we being good ancestors?" turns deep time from a source of fatalism into a demand for responsibility toward beings who will inherit our residues.
Warming and human disturbance are reversing the underground's function as a place where things stay hidden. Melting glaciers, thawing permafrost and eroding ground are releasing bodies, pathogens, weapons, methane and old pollutants that were meant to stay buried. The "unburial" is a signature of the age: what we once put below out of sight now returns, often in altered and dangerous forms.