At the climax of his address, Gerard Barron pulled up a split-screen showing two photographic visions of the future: an apocalyptic nickel strip mine, and a pristine stretch of deep seabed.

The former depicted business-as-usual land mining in Indonesia, and the latter was a stretch of seabed off the Peru coast that had been dragged with a plow about 30 years earlier, which appeared to have naturally recovered. “When we think of the planet as being over four-and-a-half billion years old, the planet will do a good job of repairing itself.”