by Michael Mann & Gavin Schmidt
The precise factors underlying the so-called “Little Ice Age” (LIA) have been intensely debated within the scientific community. One key metric in this debate is the spatial pattern of cooling which may provide a ‘fingerprint’ of the underlying climate change, whether that was externally forced (from solar or volcanic activity) or was part of an intrinsic mode of variability.
Surface temperatures in parts of Europe appear to have have averaged nearly 1