Highlighted Article: COLD WATER? The Oceans and Climate Change

From: The Global Warming Policy Foundation

By: David Whitehouse

Date: November, 2019

COLD WATER? The Oceans and Climate Change

"Executive summary

• The study of ocean heat content (OHC) is a subject struggling with inadequate data, but exposed in a public forum.
• Only since the introduction of data from the Argo array have there been convincing estimates of errors. The inhomogeneity of different data sets is a major problem.
• There is no real understanding of the difference between random and systematic errors in OHC data.
• Changes in OHC are at the limits of our ability to measure, and made with much uncertainty and many unknowns.
• It is likely that OHC has increased over the past few decades, although this is not a highly robust result. Movements in energy are typically 1022 J from year to year, with large uncertainties. For comparison, this is about the energy the Earth receives from the Sun every day and about twice the world’s energy consumption. It represents a small change in the ocean’s total heat content (about 165 × 1025 J).
• It is difficult to put these changes into a proper historical context. There is much uncertainty about long-term ocean cycles, and the OHC earlier in the Holocene seems to have been larger than today and changing on the same timescales as seen today. In addition, the timescales for change in the deep ocean are very long. This could mean that some (possibly most) of what is happening there has nothing to do with recent human activity.
• The jump in the OHC data seen at the time of the introduction of the Argo floats is a big problem. Post-Argo behavior is different to what it was before Argo. A case could be made to disregard all OHC observations made before the Argo deployment and treat Argo data on its own, and this is sometimes done; when it is, evidence for changes in OHC is much reduced.
• There are major uncertainties in our understanding of the way heat is transported from the ocean surface to the depths.
• Almost all of the ocean warming is coming from one region, 30°–50°S, in the Pacific Ocean." ...

COLD WATER? The Oceans and Climate Change