Last week, NASA and the National Oceanic and Atmospheric Administration (NOAA) reported that 2014 was officially the hottest year on record. This marked the 14th year of record-breaking heat to occur in the 21st century, but Dr. John Abraham, professor of thermal sciences at the University of St. Thomas, says this overlooks a more disturbing statistic: Oceans are warming so quickly that they are “breaking scientists’ charts.”
In a recent article for The Guardian, Dr. Abraham writes,
“We tend to focus on the global temperature average which is the average of air temperatures near the ground (or at the sea surface). This past year, global air temperatures were record-breaking. But that isn’t the same as global warming. Global warming is properly viewed as the amount of heat contained within the Earth’s energy system. So, air temperatures may go up and down on any given year as energy moves to or from the air (primarily from the ocean). What we really want to know is, did the Earth’s energy go up or down? […]
“Well, it turns out that the energy stored within the ocean (which is 90% or more of the total ‘global warming’ heat), increased significantly. A plot from NOAA is shown above. You can see that the last data point (the red curve), is, literally off the chart.”
The chart Abraham alludes to is embedded below:
This data observes heat content for ocean depths between zero and 2,000 meters between 1955 and 2010. NOAA has provided a much more thorough analysis, which can be found here.
Climate change deniers (such as the current head of the Senate’s Environment Committee, Jim Inhofe) argue that global warming has slowed down or even paused since 1998 and that the past 15 years have shown no change in the Earth’s thermal energy. According to Dr. Abraham, this latest ocean warming data “is the clearest nail in that coffin.”
Essentially, what is happening is that the oceans are absorbing so much of the Earth’s rising heat (90 percent) that air temperatures have risen relatively little by comparison. Shallower temperatures seemed to slow around 2003, but this is due to more heat accumulating at deeper ocean depths. A 2013 study published in Geophysical Research Letters shows that 30 percent of ocean warming has occurred below 700 meters in the last decade, a finding consistent with a 2012 study by Nuccitelli et al.
The writers of the 2013 study state that this deep ocean warming is “the most sustained warming trend in this record of OHC [ocean heat content]. Indeed, recent warming rates of the waters below 700m appear to be unprecedented.”
However, this state will not last. A study published last year in the journal Nature Climate Change indicates that accelerating winds have pushed global heat down into the subsurface ocean, resulting in cooler water being pushed to the surface.
Is there evidence that there is a significant change of trend from 1998? (Spoiler: No.) pic.twitter.com/MdNCAul7E7
— Gavin Schmidt (@ClimateOfGavin) January 16, 2015
This “heat uptake is by no means permanent,” said Professor Matthew England, lead author of the study and a Chief Investigator at the ARC Center of Excellence for Climate System Science at UNSW Australia, in a news release. “When the trade wind strength returns to normal – as it inevitably will – our research suggests heat will quickly accumulate in the atmosphere. So global temperatures look set to rise rapidly out of the hiatus, returning to the levels projected within as little as a decade.”