Simmering seas: “extreme” heat is now normal for a majority of the ocean’s surface.

As the planet warms around us, a lot of predicted changes are being confirmed by science. The drought forecast I wrote about a little while back is just one indicator of how the world around us is seething. Those of us who’ve paid even a little attention have been able to see and feel the changes around us, and anyone keeping up with ecological research knows that every other life form on the planet can see and feel the change as well, even if they lack the capacity to understand what’s going on.  To the complete surprise of nobody, oceans continue getting hotter. Research from the Monterey Bay Aquarium now indicates that “extreme heat” is starting to become part of normal conditions:

Researchers conducted the study by mapping 150 years of sea surface temperatures to determine a fixed historical benchmark for marine heat extremes. The scientists then looked at how often and how much of the ocean surpassed this point. The first year in which more than half of the ocean experienced heat extremes was 2014. The trend continued in subsequent years, reaching 57 percent of the ocean in 2019, the last year measured in the study. Using this benchmark, just two percent of the ocean surface was experiencing extremely warm temperatures at the end of the 19th century.

“Climate change is not a future event,” said Dr. Kyle Van Houtan, who headed the research team during his tenure as chief scientist for the aquarium. “The reality is that it’s been affecting us for a while. Our research shows that for the last seven years more than half of the ocean has experienced extreme heat.”

“These dramatic changes we’ve recorded in the ocean are yet another piece of evidence that should be a wake-up call to act on climate change,” he added.” We are experiencing it now, and it is speeding up.”

The study grew from separate research into the history of kelp forest changes throughout California. Van Houtan and team discovered that sea surface heat extremes, which are key stressors for canopy kelps, needed to be quantified and mapped along the California coast throughout the last century. The researchers then decided to expand the investigation beyond California to better understand the long-term frequency and location of extreme marine heat across the global ocean surface.

Using historic records, aquarium scientists first determined the average temperatures for the ocean’s surface over the period spanning 1870 to 1919. Then they identified the most dramatic ocean warming that occurred during that period — the top two percent of temperature increases — and defined that as “extreme heat.” The team then mapped the extremes over time, examining whether they occur regularly or are becoming more frequent.

“Today, the majority of the ocean’s surface has warmed to temperatures that only a century ago occurred as rare, once-in-50-year extreme warming events,” Van Houtan said.

The fact that I’m able to maintain this blog means that we still have time and resources to make changes that would both slow down the warming, and improve everyone’s ability to survive and thrive. That said, it’s hard not to think of the proverbial frog in its slowly warming pot of water.


  1. StevoR says

    So folks. That’s most of the planet then.*

    Though people especially in the media seem to overlook that and think of the ocean as something far smaller and less important than it really is.

    Shared. Thankyou Abe Drayton.

    * The surface of earth anyhow, excluding y’know, its mantle, and both inner and outer cores.

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