We only need to look to the Mediterranean Sea, and, more recently, the Great Lakes, for dramatic illustrations of what lies in store if we don’t act now.

"On January 5, 2018, a paper published in the journal Science delivered a sobering message: The oxygenation of open oceans and coastal seas has been steadily declining during the past half century. The volume of ocean with no oxygen at all has quadrupled, and the volume where oxygen levels are falling dangerously low has increased even more. We’re seeing the same thing happen in major lakes...

We only need to look to the Mediterranean Sea, and, more recently, the Great Lakes, for dramatic illustrations of what lies in store if we don’t act now.

"On January 5, 2018, a paper published in the journal Science delivered a sobering message: The oxygenation of open oceans and coastal seas has been steadily declining during the past half century. The volume of ocean with no oxygen at all has quadrupled, and the volume where oxygen levels are falling dangerously low has increased even more. We’re seeing the same thing happen in major lakes...