Ocean Temperatures Have Gone Full Year At Record High Temperatures, Worrying Scientists

An Atlantic Ocean sunrise on an usually warm 
morning in Bethany Beach, Delaware, December, 2022.
Oceans worldwide are now experiencing
record high temperatures. 

The world's oceans have been at record warm levels now for over a  year.  

They have been gradually warming under the influence of climate change, but for the past year, they've heated up at a much faster rate. The oceans are hotter than ever, by a long shot. 

That's bad news for us humans. Hotter oceans make hurricanes, typhoons and other storms that eventually hit land stronger and more destructive. 

The hotter oceans put more water vapor into the air, sometimes helping to turn downpours on land into catastrophic flooding torrents of rain.

The record ocean temperatures are also screwing up food chains in all that water, which could have effects on world food supplies.

So what gives?

Scientists aren't sure, but they are concerned, as Elizabeth Kolbert noted in The New Yorker:

"'We don't really know what's going on,' said Gavin Schmidt, the director of NASA's Goddard Institute for Space Studies told me. 'And we haven't known what's going on since about March of last year.' He called the situation 'disquieting.'"

As Wired noted, ocean temperatures in the tropical Atlantic are already where they should be in June. That's the start of hurricane season, and those warm temperatures now are theoretically enough to support a tropical storm or hurricane, 

"It's really getting to be strange that we're just seeing the records break by this much, and for this long,' said Brian McNoldy, a University of Miami hurricane researcher.

Scientists are wondering if the year-long unprecedented global ocean heat wave is just a blip, an outlier in what has been a gradual warming of the oceans created by climate change? Or is something else going on?  

Kolbert in the New Yorker again:

"For the last twelve months, the seas have been so feverish that scientists are starting to worry about not just the physical impacts of all that heat but the theoretical implications. Can the past year be explained by what's already known about climate change, or are there forces at work that haven't been accounted for? And if it's the latter, does this mean the projections for warming, already decidedly grim, are underestimating the dangers?"

Explanations are mostly speculation at this point.  

El Nino usually makes both Earth's atmosphere and oceans warmer. And we've been in an El Nino for the past year. But the oceans have warmed in the past year much more than we'd expect from an El Nino.

An enormous volcanic eruption in the South Pacific back in 2022 released a huge amount of water vapor high into the atmosphere. That might have temporarily added a little heat to the world. The solar cycle is now active. Perhaps that's contributing a little to heating the world, including its oceans. 

And as I've previously reported on, environmental regulations have sharply reduced sulfur emissions from ships, which meant there was less pollution in the air to block the sun. Or this past year's hot oceans could be just a weird blip, some sort of odd natural variability.  Or some or all of the above.

Nobody is really sure. 

Kolbert's New Yorker article says a good test is coming up to help determine whether we should panic over the oddly hot seas.

El Nino is transitioning to the cooler La Nina ocean and weather pattern.  Normally, La Nina tends to blunt the effects of climate change a bit by having a cooling influence on both the lower atmosphere and the oceans. 

If La Nina brings ocean temperatures more in line toward what scientist had expected, then we can breathe a slight, partial sigh of relief.  

In recent days, scientists have started to notice global sea temperatures hinting at a cooling as El Nino fades, but the ocean warmth is still at record heights.  

There is precedence for a big spike in ocean temperatures like we're seeing now. El Ninos in the 1940s brought ocean temperatures from well below normal to a fair amount above normal.  The increase in temperature back then was of a similar scale we're seeing now.

The trouble is, climate change had made oceans warmer. So the latest El Nino appears to have taken a much warmer than normal ocean system and brought those temperatures to extreme heights. 

The New Yorker said that Susan Wijffels, a senior scientist at the Woods Hole Oceanographic Institution thinks the real test will be over the next 12 months. "If temperatures remain very high, then I would say more people in the community will be really alarmed and say, 'OK, this is outside of what we can explain.'"

Oceans that stay hotter than climatologists had expected can can create a "positive feedback" in which the warmth causes more warmth. Wired explains: 

 "....when the surface warms, it creates a cap of hot water, blocking the nutrients in colder waters below from mixing upwards. 

Phytoplankton need those nutrients to properly grow and sequester carbon, thus mitigating climate change. If warming-induced stratification gets bad enough, 'we don't see what we would call a spring bloom,; says Dennis Hansel, an oceanographer from the University of Miami. 'Those are much harder to make happen if you don't bring nutrients back up to the surface rot support the growth of those algae." 

Whether or not oceans come off their big fever in the past year, those seas will continue to be a growing problem for us in the decades to come. The upward temperature trend will continue, causing more storms and sea level rise. We just don't know how fast that upward trend will become.