Ocean Trifecta

The oceans are probably in for some dramatic changes in the coming decades. They’ll get warmer and more acidic, and they may lose some of their oxygen as well – a trifecta that’s likely to be a losing bet for us as well as the oceans.

As we pump more and more carbon dioxide into the air by burning gasoline and other hydrocarbons, the atmosphere gets warmer. Some of that heat is transferred to the oceans – mostly to the surface layers so far, but eventually to the deeper ocean as well. Among other effects, that can change the way that nutrients travel from deeper waters to the surface.

The oceans also absorb some of the carbon dioxide from the air. That makes the water more acidic, which damages corals and shellfish and may affect other life as well.

A report a few years ago pointed out another likely problem: a loss of oxygen. Although no one expects it to fall to damaging levels across most of the oceans, we’re likely to see more “dead zones” and other regional problems.

It’s not certain how these changes will play out. Some organisms and regions are likely to benefit, while others are likely to be harmed. And there’s a good chance that the changes could reduce the ability of the oceans to absorb more CO2 from the air – and could even cause them to add carbon to the air – which would increase air temperatures.

So while we can’t know all the effects of our changing oceans, we can be pretty sure that many of them won’t be good – for life in the oceans, or life beyond the oceans, either.