Emergent Constraints on Future Projections of Tibetan Plateau Warming in Winter

The Tibetan Plateau (TP) is an area highly sensitive to climate change and is warming faster than the global average. The TP temperature change has a significant impact on the local ecological environment and the downstream weather and climate. The TP will undoubtedly warm in the future, but the warming extent is uncertain. Using the Coupled Model Inter-comparison Project Phase 6 multi-model ensemble, we found that models simulating smaller TP temperature increases in recent decades tend to project weaker warming in the future. This relationship is driven by the simulation of snowmelt response to greenhouse gas increases, as snow-related albedo feedback dominates the TP temperature changes in both historical and future periods. Based on a two-step emergent constraint approach, the rectified TP warming magnitude increases by about 0.3 degrees C compared to the unconstrained result under both the medium and high emission scenarios, and the inter-model uncertainty is reduced by about 60%. The Tibetan Plateau (TP), known as "the third pole of the world," is the highest terrain on Earth. It has experienced a rapid increase in surface temperature over the past few decades, which has significantly impacted the local ecological environment and downstream weather and climate. Therefore, how the surface temperature of the TP will change in the future is of concern to both the scientific community and society at large. Although a future warming trend over the TP is evident in model projections, the extent of this warming remains highly uncertain. Based on a multi-model ensemble, we found that the projected temperature change over the TP during the boreal winter is significantly influenced by the simulation of TP temperature changes in recent decades, which is related to model sensitivities in simulating the snowmelt rate in response to greenhouse gas increases. Removing the model bias using observations would further increase the projected future warming over the TP, meaning that humanity will face greater challenges. A two-step emergent constraint (EC) technique is developed for projections of the Tibetan Plateau (TP) warming in the boreal winter The EC arises from model sensitivities in simulating snow cover change in response to greenhouse gas increases Constrained results effectively reduce inter-model uncertainty and show stronger warming over the TP than the original results