Records of Spanish shipwrecks combined with tree-ring records show the period 1645 to 1715 had the fewest Caribbean hurricanes since 1500, according to new research. The study is the first to use shipwrecks as a proxy for hurricane activity. The researchers found a 75 percent reduction in the number of Caribbean hurricanes from 1645-1715, a time that had little sunspot activity and cool temperatures in the Northern Hemisphere.