Climate change is radically altering the world's oceans, threatening an important food source by making it more difficult to fish. The latest report from the Intergovernmental Panel on Climate Change (IPCC), released Monday outlines how we've already passed a number of "tipping points," irreversibly changing ocean ecosystems.
"The IPCC has made very clear that the global ocean is bearing the brunt of man-made climate change," said Global Ocean Commission Co-Chair Trevor Manuel in statement.
Since adaptation is slow, fish populations are more likely to migrate to cooler waters than to adjust to hotter temperatures. That's bad news for fishermen in tropical areas, where fish are expected to move further away from the coasts.
Warming seas are also leading to lower levels of dissolved oxygen. According to the report, "the progressive expansion of oxygen minimum zones and anoxic 'dead zones' is projected to further constrain fish habitat." That can also have a negative impact on the diversity of marine species and extinctions are expected.
Ocean acidification is also expected to increase, more bad news for many species, particularly those in polar regions and living in coral reefs. "Simultaneous drivers"—the combination of acidification, decreased oxygen levels, warming temperatures and pollution—are expected to make it difficult for coral reefs to survive.
But some species will be well-suited to the changes. "Take, for example, the oxygen-stripped waters of the East China and Yellow seas," writes Gwynn Guilford for Quartz. "As other animals have fled or died, Nomura jellyfish—gelatinous peach-colored behemoths the size of a large refrigerator—have thrived."
The report is grim, however we can only hope these predictions will spur citizens and governments alike to take action.