Oceans are retaining 60 percent more heat than previously thought, study says

The study found that the increase is causing faster rates of climate change, which will have impacts in Minnesota and around the world.

by Nikki Pederson

Editor’s Note: After this article’s publication, authors of the study said that errors existed in the study’s findings and have submitted a correction to the journal in which it was published. An update to the story can be found here. 

The Earth’s oceans are retaining more heat than previously thought, which suggests a faster rate of global warming that could result in climate changes in Minnesota, according to new research.

The study published late last month by Princeton University and the Scripps Research Institute found that the oceans are retaining 60 percent more heat each year than previously thought. The new, larger estimates suggest that climate change is happening at a faster rate.

“We can look in the ocean and … essentially develop a very pretty precise estimate of how the climate is changing because that’s where the heat is — in the ocean,” said Matthew Long, a scientist at the National Center for Atmospheric Research who was involved with the study.

More than 93 percent of all the heat people have contributed to the planet has been absorbed by the oceans. Oceans absorb the majority of all excess energy and heat released into the atmosphere, making measuring the ocean’s heat content important to understanding climate change, Long said. 

Global warming has led to deoxygenation, rising sea levels and more extreme weather. Carbon dioxide emissions are also making the oceans more acidic, which can bleach coral reefs and affect ocean biodiversity. 

However, measuring ocean temperature is difficult and previous measurements were imperfect due to the size of oceans and how vastly different they can be across the globe, he added. To get around this, researchers estimated the temperature increase by measuring the volume of oxygen and carbon dioxide in the atmosphere and the volume that has escaped from the ocean.

“If scientists are saying the oceans have more heat in them than we initially thought, that’s just bad news for global warming and climate change,” said Tracy Twine, a University of Minnesota professor in the Department of Soil, Water and Climate. “That just means whatever is predicted to happen in Minnesota could be exacerbated and amplified.”

Even areas hundreds of miles away from oceans, such as Minnesota and other Midwestern states, are influenced by the ocean and its changes. While land areas and the atmosphere absorb some sunlight, the majority of the sun’s radiation is absorbed by the ocean. Especially in the tropical waters around the equator, the ocean acts as a large, heat-retaining solar panel, according to the National Oceanic and Atmospheric Administration. 

“What happens in the oceans affects land because of the global circulation of air energy — this is what drives our weather here in Minnesota and elsewhere,” Twine said. “Air picks up energy as it flows over water and transports that energy through the atmosphere.”

The effects of climate change are already creating new normals in Minnesota. 

“The ocean affects our weather and climate here [in Minnesota], but the relationship is incredibly complicated,” said Kenny Blumenfeld, a climatologist at the Minnesota Department of Natural Resources. “Because the oceans are huge and contain a lot more stored heat than the land is capable of containing, we know that that contributes to a warmer atmosphere and contributes also to more moisture in the atmosphere.”

Minnesota’s climate has been increasingly warm and wet, Blumenfeld said. While greenhouse gases don’t make things hotter, they prevent the weather from getting colder. This means that extreme colds are becoming less frequent and average daily temperatures are warmer than they have ever been, he said.

“What used to be really common now barely happens at all, when it comes to extreme cold,” he added. “And what is now very cold used to be very common.”