I initially parsed it as five summers, each lasting 500 years, in a time span of 15 years. Logic then kicked in and "corrected" it to five summers, each as summ

I initially parsed it as five summers, each lasting 500 years, in a time span of 15 years. Logic then kicked in and "corrected" it to five summers, each as summer-y as 500 years worth of summers combined, in a time span of 15 years. I had to read the article to finally made sense of it.