runs all the way around the base of the island, except above the vents,
where the barnacles are missing.
“Barnacles are pretty tough,” Hall-Spencer observes. He is British,
with dirty blond hair that sticks up in unpredictable directions. He’s
wearing a dry suit, which is a sort of wet suit designed to keep its owner
from ever getting wet, and it makes him look as if he’s preparing for a
space journey. Buia is Italian, with reddish brown hair that reaches her
shoulders. She strips down to her bathing suit and pulls on her wet suit
with one expert motion. I try to emulate her with a suit I have borrowed
for the occasion. It is, I learn as I tug at the zipper, about half a size too
small. We all put on masks and flippers and flop in.
The water is frigid. Hall-Spencer is carrying a knife. He pries some sea
urchins from a rock and holds them out to me. Their spines are an inky
black. We swim on, along the southern shore of the island, toward the
vents. Hall-Spencer and Buia keep pausing to gather samples—corals,
snails, seaweeds, mussels—which they place in mesh sacs that drag
behind them in the water. When we get close enough, I start to see
bubbles rising from the sea floor, like beads of quicksilver. Beds of
seagrass wave beneath us. The blades are a peculiarly vivid green. This, I
later learn, is because the tiny organisms that usually coat them, dulling
their color, are missing. The closer we get to the vents, the less there is to
collect. The sea urchins drop away, and so, too, do the mussels and the
barnacles. Buia finds some hapless limpets attached to the cliff. Their
shells have wasted away almost to the point of transparency. Swarms of
jellyfish waft by, just a shade paler than the sea.
“Watch out,” Hall-Spencer warns. “They sting.”
SINCE the start of the industrial revolution, humans have burned
through enough fossil fuels—coal, oil, and natural gas—to add some 365
billion metric tons of carbon to the atmosphere. Deforestation has
contributed another 180 billion tons. Each year, we throw up another nine
billion tons or so, an amount that’s been increasing by as much as six