A native of Regina, Mitchell has been one of Canada’s leading science journalists and authors for decades, getting her start at the Financial Post and then the Globe and Mail. She has written about everything from cancer to climate change, evolution to Arctic exploration. Her most recent book, The Spinning Magnet, explains Earth’s electromagnetic field and how a reversal of the planet’s magnetic poles might impact our modern infrastructure.

About the threat posed by declining ocean health, Mitchell is unequivocal: “If everything on land were to die tomorrow, everything in the ocean would be fine. But if everything in the ocean were to die tomorrow, everything on land would die too.”

Covering more than 70 per cent of Earth’s surface, oceans play a hugely important role in absorbing carbon dioxide from the atmosphere and cycling other nutrients, but as humans continue to pump more and more CO2 into the atmosphere, the chemistry of the ocean is changing. As Mitchell puts it, chemistry determines biology, and in the decade since Sea Sick, worrying trends such as coral bleaching, the deoxygenation of coastal areas and the movement of marine organisms away from the coasts and equator have only intensified. 

“[This is] a hinge moment in the history of our civilization,” says Mitchell. “This is the moment that’s going to make all the difference, not just for us but for all sorts of other species. We don’t have the time or luxury to delay anymore.”