Given projected warming (e.g., histograms; Fig. 1), the two temperature-response models (lines, top of Fig. 1) clearly indicate that the risk of nephrolithiasis will increase. The predicted distribution of climate-related changes in urolithiasis strongly depends on the form of the temperature-dependence model. In the linear model, stone risk depends on baseline risk and rise in temperature, and therefore risk increase is concentrated in the midcontinent and West (Fig. 2). Arbitrarily defining the stone belt as those areas with a risk ratio ≥1.2 relative to the Northeast, the net effect of warming on stone risk is most easily visualized as a northward expansion of this belt from the Southeast into the Midwest (Fig. 3) This newly expanded stone belt occupies the southeastern half of the nation and all of California by 2050 and significantly beyond that by 2095.