Table 3 Cumulative greenhouse gas emissions (GHG; see Supplemental methods S1 for how Amstrup and Bitz²¹ derived these data) estimated to result in a 10% increase recruitment failure (RF) and the year in which that threshold is projected to be crossed for polar bears in the Chukchi Sea (CS) and Southern Beaufort Sea (SBS) subpopulations based on combinations of two different values of sea ice concentration (SIC) used to define sea ice extent (i.e., < 15% or < 30% sea ice concentration), two different definitions of the threshold used to define an ice-free day (IFD; i.e., < 15% or < 30% of 10-year March average sea ice concentration), and two delineations of the subpopulation boundaries (i.e., that used by Amstrup and Bitz²¹ and by Rode et al.²³) for both linear and logistic curves fit to the relationship between RF and GHG described in Molnár et al.¹⁶. The scenarios included in Amstrup and Bitz²¹ is depicted in bold. Subpopulation boundaries as defined by Amstrup and Bitz²¹ are identified as “AmBi” and boundaries defined by Rode et al.²³ are identified as “Rode”.

From: Model sensitivity limits attribution of greenhouse gas emissions to polar bear demographic rates