Climatic data and characterization of the Baja California Peninsula
We characterized the current climatic conditions of the Baja California peninsula by using 19 bioclimatic variables (Supporting Information) with a spatial resolution of 1 km obtained from Worldclim (Fick & Hijmans, 2017). Additionally, we obtained data from two different global circulation models (CGMs): the Interdisciplinary Research on Climate (MIROC v3.2; Hasumi & Emori, 2004) and the Community Climate System Model (CCSM3; Collins et al., 2006), for characterizing the climate during the Last Glacial Maximum (LGM; ~ 21 kya).
We calculated the difference between present-day and LGM conditions for all temperature and precipitation variables for both GCMs. Since previous work showed discrepancies between GCM conditions on the BCP that affected SDMs (See Supporting Information for details), we compared the GCM differences to paleoprecipitation proxy data published for alluvial fan, pollen, lake core record, and midden data, across southern California and the Baja peninsula to determine which GCM was more consistent with paleoclimate data at the LGM in this region.