Recent research demonstrates another, equally powerful reason for Spain’s imperial retrenchment: the Little Ice Age. Both physical and written sources give clear evidence of a catastrophic shift in climate during the last decade of the sixteenth century and the first years of the seventeenth. A series of large volcanic eruptions, in addition to a long-term cooling trend, brought some of the coldest global temperatures in thousands of years. A shift in atmospheric circulation contributed year upon year of unseasonable weather, floods, and droughts.
