Figure 5.

Projected baseline and future Lyme disease risk ranges under SSP1 × RCP2.6 and SSP4 × RCP4.5 scenarios. The projected distribution of risk indicator, DIN (infected nymphal ticks per ha), at the baseline of 2010 in (A) winter and (B) peak season are classified into five levels: null ($\text{DIN}=0$), negligible ($\text{DIN}<82$), low ($82\le \text{DIN}<698$), moderate ($698\le \text{DIN}<\mathrm{1,608}$), and high ($\text{DIN}\ge \mathrm{1,608}$). Among the six combined scenarios considered, the SSP1 × RCP2.6 represents the least risky future in which the low emissions scenario (RCP2.6) is combined with a sustainability socioeconomic scenario (SSP1). Both the (C) winter low-risk range and (D) peak season high-risk range were projected to likely decrease by the 2050s. The blue/red color gradients indicate agreement among projections under different climate models, with darker meaning higher agreement. The patterned blue/red area refers to the baseline projections for comparison. The SSP4 × RCP4.5 is the most risky future in which the intermediate emissions scenario (RCP4.5) is combined with an unequal future of increased socioeconomic disparities (SSP4), under which an overall increase and geographical changes in both (E) winter low-risk range and (F) peak season high-risk range by the 2050s were projected.