Climate science and understanding how climate change may affect the Greater Yellowstone Ecosystem (GYE) have come a long way since our 1992 Yellowstone Science article (Romme and Turner 1992, based on Romme and Turner 1991). In 1992, the potential for global warming driven by anthropogenic emissions of atmospheric greenhouse gases (GHG) was hypothesized but not yet demonstrated. Global climate models were in their infancy, and evidence of climate trends was beginning to emerge. In 1992, ecologists had no quantitative predictions of climate change that could be used to anticipate ecological responses. In our earlier article, we explored logical consequences of qualitative scenarios of climate warming that differed in whether warming was accompanied by drier, intermediate, or wetter conditions.