This year’s ocean temperatures are being described as “unprecedented”, “off the charts”, and “beyond extreme”. I have to stare at this plot for awhile to get it, but basically the 0 line is the long-term average, presumably over 50 years or so. Then each individual line shows the difference between actual temperature and that average, for one year, over the course of the year. So not only is the departure of more than 1.5 C in June 2023 way above the average, it is way above any other extremes seen over the last 50 years.

The article gives physical explanations, including El Nino, changes in ocean currents, and changes in wind currents. It says climate change is a factor but doesn’t really reach conclusions on how much of a factor. I think it almost certainly has to be a factor. But the important question to me is whether this is an extreme fluctuation the likes of which we are going to start seeing occasionally, or the start of some runaway trend we are going to start seeing frequently and may even get worse? The article does not suggest anything like the latter. Tipping points concern me – could this be an early warning that we have hit some tipping point in terms of runaway methane release for example? The article doesn’t suggest that. Let’s hope not. If it is, it would be an “unprecedented” planetary emergency and we would need to pull out the stops and try any and all of those risky geoengineering ideas we have been hearing about, because “risky” is by definition less risky than “certain doom”. Let’s hope not. The fluctuation does appear to be subsiding, so we can see where we are next year around this time.