In 2007, my colleagues and I published a study examining of the likelihood of the 2005 “hot spot” occurring with and without human influence on the climate system. The study contrasted model simulations of the Caribbean with historical data and then computed the statistics of extreme ocean temperature events. The second slide summarizes some of the key results of from study. In a nutshell, our best analysis concluded the 2005 Caribbean “heat wave” would likely be on the order of a once in a thousand year event, had there been no human-generated greenhouse gas or aerosol emissions since the Industrial Revolution (“natural forcing”). By the 1990s, the human forcings increased the odds to once in 10-50 years. And continued warming under “business as usual” would make such heat waves happen in three out of every four years.
Five years later, a Caribbean “heat wave” has happened again. I’ve been writing for months that there was a strong likelihood of extensive coral bleaching in the Caribbean this fall according to NOAA’s advance forecast of sea surface temperatures (in fact, we had a good inkling of this last summer). Now we’re getting reports of bleaching from observers in the Caribbean. Add this to the observations (following predictions, once again!) from Southeast Asia and the Equatorial Pacific, and we have what may be the most, or second most, extensive “global” coral bleaching event in recorded history.
For all those writing about this event, keep in mind the predictions. This is what the scientific community predicted was likely to happen. An event which we calculated would be a once in a millennium occurrence without human impact on the climate, happened again five years later.