Heat waves are unbearable. Well ok, unless you actually die from a heat wave then “unbearable” is technically an exaggeration. But they definitely aren’t fun. That’s something you can’t argue. You think you can’t handle a summer heat wave. You sweat your way through a few really hot days. You crank the A/C and run up your electricity bill. And you complain. A lot.
Ok, so we’re all familiar with heat waves. We know what they are. And that exact same concept applies to the ocean. Just like the summer afternoon sun heats asphalt to the point it’ll melt your sandals and you get to enjoy a few sleepless nights, our planet’s largest bodies of water also endure days at a time of extended extreme heating, which you’d imagine sucks just as much for fish and coral and other underwater stuff. It’s a natural thing. It’s nothing to freak out over even if it sounds like it’s straight out of An Inconvenient Truth. What is worth noting, though, is the frequency they’re occurring at nowadays.
Scientists define marine heat waves as a bout of hot water lasting for at least five consecutive days. And that water must be exceptionally warm for its region or area in that time period. The extreme heat can definitely wreak havoc on their underwater environment and is especially linked to coral bleaching and damaging reef environments, but a drastic shift in temperature isn’t going to destroy anything and everything in its path under the surface of the ocean.
When researchers dug through data recently, they found that these marine heat waves are starting to happen more frequently and last noticeably longer than they used to in a little more than the past century. Their sea-surface temperature data dated back as far as 1900 and their satellite data was collected from as far back as 1982, revealing a handful of changes. First, the number of days each year some part of the ocean has a heat wave increased by 54 percent between 1925 and 2016. They are also 34 percent more likely in that same time period and lasting 17 percent longer now than a century ago.
What does it all mean? Well, scientists do attribute the rise in marine heat waves to climate change. And yes, because of this, they expect the trend to continue to rise.