Why Ocean Warming Might Be the Biggest Threat to the Food Supply

Calling it “the greatest hidden challenge of our generation,” the International Union for Conservation of Nature this month released an alarming and exhaustive report on a little-known effect of global climate change: ocean warming.

Since 1970, 93 percent of enhanced heating from the greenhouse effect has been absorbed by the oceans. By the year 2100, the mean ocean temperature will likely increase by an astounding 33 to 39 degrees Fahrenheit. The most severe changes will occur in the southern hemisphere, where polar ice shelves have been collapsing for years.

The report asserts that ocean warming will have devastating impacts on marine life, and in term, our food supply. More than 4.3 billion people—most of whom live in developing countries—depend on fish for 15 percent of their daily calories, according to the report.

In other words, ocean warming could have a huge impact on our food system—it’s not just that your spicy tuna roll might cost a little bit more. Unless we lessen our contributions to global climate change, here’s what will happen.

The supply of fish and seafood will shrink

When ocean temperatures are altered, some species of sea life adapt. Others, not so much. For many edible species, changes in ocean temperatures alter their behavior and even their physiology—including their ability to reproduce. As fish in search of colder waters migrate toward the poles, the seafood supply rapidly diminishes elsewhere. Ocean warming will also alter seasonality in many places, impacting the stability of fish supply.

Fishing communities will lose their livelihoods

When marine life flees warm water temperatures, many villages will no longer be able to depend on aquaculture to survive. Food insecurity will increase, and many of the communities that formerly subsisted on fish may no longer be able to afford to consume seafood.

Many will no longer be able to eat their culture’s traditional cuisine

As some varieties of fish die off or relocate, seafood may become more expensive. Communities that have traditionally eaten seafood as part of their native cuisine may not be able to afford it, now that it’s no longer readily available. This change will be particularly prevalent in tropical and subtropical climates, according to the report.

Keep in mind that these three changes aren’t the only consequences of ocean warming—it will also likely intensify our weather patterns, causing more extreme storms, hurricanes, droughts, and floods. Then there’s the issue of ocean acidification, which presents a whole new set of challenges for the environment.

Needless to say, ocean warming and climate change overall will have far-reaching effects on each and every one of our lives. As the report’s authors write, “It is critical that we sit up and recognize these issues and act, or we will be poorly prepared if at all for an uncertain changing future.”

Photo credit: Rowena Naylor via Stocksy