Thanks to the relentless pace at which humans are adding greenhouse gases to the atmosphere, ocean temperatures in 2021 were “the hottest ever recorded by humans,” according to a report published Tuesday.
Twenty-three scientists from around the world teamed up to analyze thousands of temperature measurements taken throughout the world’s oceans. Their results were published on Tuesday in the journal Advances in Atmospheric Sciences.
The measurements, taken at least 2,000 meters (about 6,500ft) deep and spread across the globe, paint a very clear picture: The world’s oceans, in 2021, were the hottest ever recorded, and humans are responsible.
The study is also a warning that warming will continue indefinitely until we collectively take action to reduce greenhouse gas emissions.
John Abraham, a professor of thermal sciences at the University of St. Thomas School of Engineering, and one of the authors of the study writing in The Guardian says that the vast majority, actually 90 percent, of the heat associated with global warming ends up in the oceans.
“I like to say that global warming is really ocean warming. If you want to know how fast climate change is happening, the answer is in the oceans,” he writes.
There are seven maritime ocean domains that include the Indian, Tropical Atlantic, North Atlantic, Northwest Pacific, North Pacific, Southern oceans, and the Mediterranean Sea.
Four out of seven domains showed record-high heat content in 2021. The oceans warming the fastest are the Atlantic, northern Pacific, Indian and Southern Oceans.
Even though the El Niño-Southern Oscillation (ENSO) weather patterns continue to help determine short-term water temperature conditions, greenhouse gas emissions that trap solar radiation and warm the planet’s atmosphere are the bigger factor for increasing ocean warmth, according to the report.
The consequences of rising ocean temperatures
Rising ocean temperatures have already given rise to stronger tropical storms, and accelerated melting of the Earth’s polar ice, which in combination with warmer ocean waters has led to a rise in sea levels. Simply put – this translates into more sea-level rise.
Warmer oceans result in a greater amount of evaporation, which adds more moisture to the atmosphere and leads to more powerful rain events like those witnessed across the globe in 2021, as well as conditions that give rise to tornadoes.
On Monday, European researchers announced that 2021 was the Earth’s seventh warmest year on record. In its latest annual assessment, the Copernicus Climate Change Service (C3S) confirmed that 2021 had joined the unbroken warm streak since 2015.
And this was despite the cooling effect of the natural La Nina weather phenomenon. Without a doubt, this is tied to human emissions of industrial pollution and greenhouse gases. These findings suggest that a similar pattern is likely to persist into the coming decades.
As Professor Abraham says, “The information we used is absolutely crucial for understanding the planet. You could say that we took the Earth’s temperature – and the Earth’s fever is getting worse.”