A new study published in the journal Climate Dynamics confirms that the oceans are warming at distressingly quick rates.
John Abraham a co-author on the paper titled “Consensuses and discrepancies of basin-scale ocean heat content changes in different ocean analyses”, says that the single most important measure of global warming can be found in the oceans. Abraham says that “global warming” is actually “ocean warming”, and that if we want the best true grasp of how much and how quickly the climate change, the oceans must be studied.
Measuring climate change through the oceans requires many sensors being spread out around the globe which take measurements anywhere from the ocean surface to as deep as they can go. Measurements must also be taken over years, a longitudinal study must be done with the data gathered over a period of decades so that a long-term trend can be established.
The Climate Dynamics paper examines three different ocean temperature measurements in three different groups of data. It was found that regardless of which data set was used or where the data was gathered, the oceans were found to be warming.
The study described and accounted for the various important factors which can impact getting accurate temperature readings from the ocean, such as sensor biases, different types of sensors, gaps in the data, and problems using the correct baseline climate temperature.
Currently, data collection on ocean temperatures is done using the ARGO fleet, which consists of around 3,800 autonomous devices spread out uniformly across the ocean. These devices were only introduced in 2005, meaning that prior to that temperature measurements were not uniform and that the scientists had to use a sophisticated “mapping” procedure to interpolate temperatures between the actual measured temperatures.
The researchers asked a number of questions, such as how much the oceans are warming and how the warming differs based on depth and area. It was found that although there were some differences amongst the three groups of data, each ocean basin has warmed significantly over the time measured. While there may be differences in certain areas of the ocean, the central fact remains that regardless of how the measurements are taken, the oceans are definitely warming.
Dr. Gonjgie Wang, summed up the importance of the study:
“Our study confirms again a robust global ocean warming since 1970. However, there is substantial uncertainty in decadal scale ocean heat redistribution, which explains the contradictory results related to the ocean heat changes during the “slowdown” of global warming in recent decade. Therefore, we recommend a comprehensive evaluation in the future for the existing ocean subsurface temperature datasets. Further, an improved ocean observation network is required to monitor the ocean change: extending the observations in the boundary currents systems and deep oceans (below 2000-m) besides maintaining the Argo network.”
Essentially, it is unquestionable that the oceans are warming, but moving forward it is important that high-quality temperature sensors are maintained in position throughout the oceans so that accurate predictions can be made about where our climate is heading.