The oceans have become more hostile to fish and other marine life that humanity consumes, and this could have a major impact on our food supply
The Intergovernmental Panel on Climate Change (IPCC), which is the U.N. official body studying the effects of the climate crisis, has released a report on the catastrophic damage human created pollution has caused to the ocean.
“The world’s ocean and cryosphere have been taking the heat for climate change for decades,” says Ko Barrett, a vice chair of the IPCC. “The consequences for nature and humanity are sweeping and severe.”
One of the most important functions of the ocean is that it regulates the temperature of the planet. Without the ocean absorbing heat, land temperatures would be dangerous to human life, but as the ocean temperature rises it is no longer able to perform that function. Sea levels have risen, hurricanes have become much more violent, and the food supply has been impacted by these changes. The open ocean is also losing its oxygen, between 0.5-3.3% between 1970 and 2010, the IPCC report found. “For decades the ocean has been acting like a sponge,” says Barrett. “But it can’t keep up.”
Globally, the average amount of oxygen in the ocean will decline by 3% to 4% and basic foundational species, which are tiny species that larger fish consume to surive, can drop as much as 14% by 2100. By 2100, the acidification of the oceans likely to have year-round corrosive conditions for shelled animals, the report predicts, for animals in the Arctic, Southern, and some parts of the North Pacific and North Atlantic oceans. All coastal ecosystems will be at high to very high risk as well, which means that the burden of the impact will go to costal regions around the world.
In the meantime, the more excess heat and carbon dioxide that the ocean absorbs, the more dangerous the water becomes to marine life.
As the water temperature rises and acidification begins to set in, there is less oxygen in the ocean, which means that fish wind up swimming farther and farther away from humanity. Warm waters also create algae blooms and red tides, which further limit the oxygen available to other marine life. As fish provide 50 percent of all protein for developing countries, this would be a major disruption in their food stores.
As far as acidification, the climate crisis has changed the very chemical make up of the ocean, making waters more acidic and dangerous to animal life. Shellfish, oysters, and other commonly consumed mollusks are having their shells eaten away and are also deprived of the basic nutritions they need to survive.
The IPCC report predicts that by 2100 the ocean will take up two to four times as much heat since 1970, and globally marine heatwaves will very likely increase by a factor of 50 by 2081-2100 if the world doesn't make efforts to severely curb its current emissions.
From the CNN article:
"The key take away from this report is that fish in the ocean are the proverbial canary in the coal mine for climate impacts," said Malin Pinsky, an ecologist who studies marine communities, who was not involved in the IPCC report. He is an associate professor at Rutgers.
"This new report is a key step in helping everyone, including policymakers, understand exactly what could happen."