I had trouble finding a good source to link anything that would support that "belief." This was about the best I could do.
Meanwhile, researchers from Duke University and Meredith College, Raleigh, North Carolina, have discovered 657 new islands this past year.
The researchers identified a total of 2,149 barrier islands worldwide using satellite images, topographical maps and navigational charts. The new total is significantly higher than the 1,492 islands identified in a 2001 survey conducted without the aid of publicly available satellite imagery.As a reminder, the trend line for global warming is 0.145 degrees per decade. Over the next ten years, it is expected that the average global temperature will rise 0.145 degrees.
By the way, just for the fun of it, the worse heat wave on record in the history of the United States was 1936. The 1936 heat wave has its own Wikipedia page. I don't think global warming was an issue then.