Ocean Temperatures Broke Another Record in 2018, and are Heating Up Faster than Previously Thought

The oceans of Planet Earth are warming at a much faster rate than previously thought–forty percent faster–according to a new report, with 2018 being the hottest year on record for the planet’s aquasphere. Using improved data collected through a worldwide network of automated robotic probes, the report also adds evidence to the now-debunked notion that there was a global warming “pause” between 1998 and 2013–the Earth continued to warm, but the extra heat was hidden away, deep in the oceans.

Employing the findings of four separate studies that used data gathered by the Argo Program, researchers from China and the US found that our oceans have been storing roughly 93 percent of the excess heat that the planet has accumulated through global warming; typically, we tend to only be concerned over the continued buildup of heat energy that is occurring in the Earth’s lower atmosphere, since this is where we live. 

Although greenhouse gases such as carbon dioxide have the potential to store a great deal of heat, liquid water has the capacity to hold nearly five times more heat than a similar volume of co2, meaning that most of the heat being built up by global warming is being absorbed by the oceans. While this grants us surface-dwellers a brief reprieve from the more direct effects of a warming atmosphere, the heat absorbed by the oceans contributes to “increases in rainfall intensity, rising sea levels, the destruction of coral reefs, declining ocean oxygen levels, and declines in ice sheets; glaciers; and ice caps in the polar regions,” according to the study. 

2018 was also the hottest year on record for the Earth’s oceans, a string of yearly records topped almost yearly since 2000. The improved data collection from Argo’s 3,800 ocean-diving probes also revealed that the oceans are warming roughly 40 percent faster than what was reported in a 2013 UN report. They also predict that, provided greenhouse gas emissions are not reigned in, the average temperature of the top 2,000 meters of the world’s oceans will increase by 0.78 degrees Celsius (1.4 degrees Fahrenheit) by 2100.

“Ocean heating is a very important indicator of climate change, and we have robust evidence that it is warming more rapidly than we thought,” explains co-author Zeke Hausfather, a graduate student in the Energy and Resources Group at the University of California, Berkeley.

“While 2018 will be the fourth warmest year on record on the surface, it will most certainly be the warmest year on record in the oceans, as was 2017 and 2016 before that,” Hausfather continues. “The global warming signal is a lot easier to detect if it is changing in the oceans than on the surface.”