Over the next century, our diets are going to change. Our dependency on international food supplies means that the ecological changes wrought by rising temperatures are going to force us to diversify at the dinner table. 

Never more so than with fish. It’s almost certain that supplies of salmon and trout are going to diminish. Combined with the effects of logging, industrial pollution and land reclamation, rising river temperatures look set to push these cold-water fish away from their traditional habitats - the hardest hit area being California. It’s not just the fisheries  - the impact will be felt on local culture, and therefore tourism. The news is equally bad from the Southern Appalachians.

Now it appears that even the colossal Bering Sea fisheries are under threat – and these provide half the fish caught in US waters every year. It’s not just about rising temperatures. Diatoms (the most common form of unicellular phytoplankton in the ocean) are vitally important for fixing carbon and therefore regulating carbon dioxide – making the ocean act as a climate-regulating CO2 "sponge". If diatoms become scarce, this regulatory process would be short-circuited – and since phytoplankton are right at the bottom of the food chain, the prognosis for ocean ecosystems could be grim.

Our diet will change – but how much? We don’t yet know how robust our planet’s oceanic ecosystems are, and how much it takes to break them. Fingers crossed that we don’t find out the hard way.

Image: RSEanes