The sea is sick. Lots of the things in it are getting pretty sick too.

Alanna Mitchell grew up on the prairies of Canada with a scientist dad and an artist mum. She learned to ask questions early on. Science finds stuff out, she tells us, and art gives it meaning. Precisely what she’s done with Sea Sick.

Mitchell started her career as a reporter for Canada’s leading national newspaper. Alongside the daily fact-finding, she was interested in nature, in the way its patterns change over time and in Darwin’s discoveries in this context. Following this up, she found herself on a scientific ship bound for the Galapagos Islands – the only way she could afford to get there – with a bunch of marine biologists. And this sparked her interest in the sea.

Countless conversations with scientists, an appointment to view the annual coral sex fest (who knew?) and a voyage to the bottom of the sea later, she’s documented the catastrophic damage that we’re wreaking on the earth’s environment and its cataclysmic impact on the oceans. It’s gloomy, frankly terrifying stuff: the impact of too much carbon dioxide in the atmosphere, the impact on the sea’s temperature, the impact on the ice, the shift in the pH balance of the waters, the doubling of the blobs (another riveting but disturbing story) and the consequences.

She isn’t an actor, she hastens to tell us up front. And part of this show is her story of why she felt compelled to stand in front of us, talking for 70 minutes when the journalist’s natural medium is the written, not spoken word. But she’s a delightfully engaging speaker for all of that. The balance between her story and the world’s story is just right. She uses some beautiful evocative language: she describes growing up with the “remorseless light on the prairies,” for example. She’s funny – which makes the content marginally more palatable. And she’s endearingly self-aware, noting the irony of her endless flights to meet scientists to find out about the damage her flights are doing to the planet.

Telling people things they don’t want to hear is a tricky gig, particularly when you’re paying for the pleasure. But the construction of this piece, and Mitchell’s delivery, is such that you don’t feel lectured at. The presentation is simple, unfussy, factual. And Franco Boni’s unobtrusive direction adds tiny, gut-wrenching flourishes: a single light on the shell attacked by the acidification of the seas, for example.

The true wonder of Sea Sick, after the step by step guide to the apocalypse, is the permission Mitchell gives to consider that change might be possible. We have eleven years to make amends, she tells us. “The end of the story is still in play.” This play is this decade’s An Inconvenient Truth – but with luck, forgiveness and a following wind, we might not be headed for a shipwreck.

(For more on how the future could look if we get our collective asses in gear, see her recent magazine article. But first, go see the show. Please.)