#Example 2: Assessing Exposure of South American Species Richness to Climate Change Metrics
For the second example, we evaluated the degree of exposure of South American species richness among amphibians, birds, and mammals (based on IUCN data, 2021) to five climate change metrics (Fig.4).  The analysis involved examining the covariation between these metrics and species richness data. The result was a map comparing richness and projected dimensions of climate change.
We obtained an historical monthly global time series data spanning from 1901 to 2020 for maximum and minimum temperature, as well as annual precipitation. Climate data had a spatial resolution of 0.5 degrees and were sourced from the updated version of the Climate Research Unit’s database (Harris et al., 2020). Four local climate change metrics were selected including temporal trend in temperature (Fig.4a), temporal trend in precipitation (Fig.4b), probability of extreme events (Fig.4c), and standardized local anomalies (Fig.4d). In addition, one regional metric, climate change velocity (Fig.4e) was considered.
To assess the complexity of climate change, the five climate change metrics were combined. Then the combined assessment of climate change was overlaid on top of the species richness map in South America, revealing the relationship between the two layers. To determine the intensity of climate change, the five metrics were rescaled to have a common range between 0 and 1 before combining them into as a single raster layer (Fig.2f).