Ocean temperatures rose so significantly in 2014 that the American scientific agency the National Oceanic and Atmospheric Administration (NOAA) had to redraw its charts.
The NOAA chart below shows the October to December 2014 average of Global Ocean Heat Content, a key measure of global warming, spiking off the ready-drawn scale.
You can see the updated graph on the second slide of this link.
The release of the Global Ocean Heat Content data follows figures which showed 2014 was also a record-breaking year for average global air temperatures, which are measured by recording the earth's temperature near the ground or at the sea surface.
But, as Dr John Abraham, professor of thermal sciences at the University of St Thomas, explained in a recent Guardian article, the global ocean data - which also showed 2014 as the hottest year on record - is a much more relevant measure of global warming.
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?
Dr John Abraham
By measuring the change in the energy of the oceans, he says, it shows that the energy stored within the ocean increased significantly, and the energy stored within the ocean makes up 90 per cent or more of the total "global warming" heat.
Dr Abraham says this is the "clearest nail in the coffin" that there has been no let up in global warming.