The oceans are losing oxygen, and climate change is the culprit.
Areas earliest hit are the western coasts of North America and Africa and the northeastern coast of South America.
The result will be major shifts in marine life, including the development of major dead zones.
And given that much of the world depend son ocean fish for protein, the changes could portend serious human and political crises.
From the American Geophysical Union:
A drop in the amount of oxygen dissolved in the oceans due to climate change is already discernible in some parts of the world and should be evident across large parts of the ocean between 2030 and 2040, according to a new study.
Scientists know that a warming climate can be expected to gradually sap oceans of oxygen, leaving fish, crabs, squid, sea stars, and other marine life struggling to breathe. But it’s been difficult to determine whether this anticipated oxygen drain is already having a noticeable impact.
“Loss of oxygen in the ocean is one of the serious side effects of a warming atmosphere, and a major threat to marine life,” said Matthew Long, a climate scientist at the National Center for Atmospheric Research and lead author of the study. “Since oxygen concentrations in the ocean naturally vary depending on variations in winds and temperature at the surface, it’s been challenging to attribute any deoxygenation to climate change. This new study tells us when we can expect the impact from climate change to overwhelm the natural variability.”