INTO THE RED: Climate and the fight of our lives
‘Nothing like this has ever happened before’: The world’s oceans are at record-high temps
Ocean surface temperatures vaulted to unprecedented levels this spring, alarming scientists and prompting predictions of increased extreme weather this year, including from hurricanes.
While ocean temperatures have been rising for at least 70 years, the new measurements taken from a network of satellites, ships, and buoys around the globe show an unexpected spike that began in March and appears to still be climbing.
“It’s just totally shocking, because it is so far out of the realm of what has been observed in the records,” said Brian McNoldy, a hurricane and climate expert at the University of Miami. “Nothing like this has ever happened before.”
The surge in temperatures is being observed at the surface of the world’s oceans — the part that fuels hurricanes and contributes to die-offs of marine life, melting sea ice and rising sea levels. Starting in early March, sea surface temperatures hit record heights, far beyond the decades of earlier recorded temperatures. April and May brought record-breaking temperatures, but starting in June, the temperature began increasing at an even faster pace.
As of Tuesday, the mean temperature across the world’s oceans was 1.2 degrees Fahrenheit higher than the historic mean from 1982 to 2011 and 0.4 degrees warmer than last year. The warming was even more acute in the North Atlantic, near northern Africa and Europe, which was two degrees higher than the historic average, according to data collected by the National Oceanic and Atmospheric Administration and compiled by the University of Maine.
Many scientists believe the surge is at least in part caused by the regular transition from La Niña, a naturally occurring phenomenon that tends to cool ocean surfaces, to a newly emerging El Niño pattern, which tends to bring warmer water to the surface. The big question, scientists say, is how much of the spike is due to natural phenomena and how much should be attributed to global warming.
The current El Niño system is projected to be especially strong, which could create much larger swings in surface temperature than normal, though some scientists note there have been strong El Niños in years past that have not produced anything like the extremes seen this year.
Scientists are also considering the possible impact of unique events, including a dearth of dust blown from the Sahara Desert, which typically provides a cooling effect on the ocean’s surface temperatures off Western Africa.
‘Part of what the ocean is doing in the climate system now is, because it was very cold leftover from before global warming, it tends to cool the atmosphere down a bit. If it quits doing that, then the atmosphere will warm up even more than it was on its own.’
Edward Boyle, a marine geochemist at MIT
The most alarming possibility is that a body of severely warmed water that had been forced deeper into the ocean by La Niña during the last three years is now rising to the surface. If true, it could be a sign oceans have been warming faster than previously thought.
“This is heating we had committed to, but it was sequestered under the surface,” said Raffaele Ferrari, an oceanographer at MIT. “Now it’s coming to the surface.”
One way or another, the warmer water is expected to exacerbate conditions already being documented across the globe, accelerating the melting of sea ice and contributing to sea level rise. The repercussions could also include altering the jet stream or super-charging hurricanes.
Another reason scientists are watching ocean temperatures so carefully is the critical long-term role oceans play in moderating the rate of planetary warming.
“Part of what the ocean is doing in the climate system now is, because it was very cold leftover from before global warming, it tends to cool the atmosphere down a bit,” said Edward Boyle, a marine geochemist at MIT. “If it quits doing that, then the atmosphere will warm up even more than it was on its own.”
No one is yet suggesting oceans have warmed so much that the planet is at a tipping point. But Gregory Johnson, a NOAA oceanographer, said the world’s oceans are currently absorbing a vast amount of excess heat from greenhouse gasses — amounting in 2021, he said, to the energy equivalent of nearly seven Hiroshima-sized atomic bombs being detonated every second.
“The ocean has been doing a huge service in absorbing all this heat,” Johnson said. “It has delayed the rate of atmospheric warming. It’s put off global warming for us. If the ocean wasn’t there, the planet would be much warmer now than it is.”
As scientists watch the surface temperature trend and analyze the potential causes and implications, many note just how startling a moment this is.
“I’m just so worried these days, I can’t even tell you,” said Glen Gawarkiewicz, an ocean scientist at the Woods Hole Oceanographic Institution who studies coastal oceanography and changes to the Gulf Stream. In recent years, he has collaborated closely with commercial fishermen in New England who have reported seeing strange things — fish migrating at times they wouldn’t expect, or tropical fish appearing in temperate waters.
When it comes to both the fisheries and increased risk of hurricanes, Gawarkiewicz said, “We’re starting to break some of the old patterns, which is really, really worrisome.”
Of note, said David Reidmiller, climate center director at the Gulf of Maine Research Institute, is that the last two years, which in the Gulf of Maine were the warmest on record, are “likely to be among the coolest ones we’ll experience for the foreseeable future.”