Projected Changes and Time of Emergence of Temperature Extremes Over Australia in CMIP5 and CMIP6

This study focuses on the projections and time of emergence (TOE) for temperature extremes over Australian regions in phase 6 Coupled Model Intercomparison Project (CMIP6) models. The model outputs are based Shared Socioeconomic Pathways (SSPs) from Tier 1 experiments (i.e., SSP1-2.6, SSP2-4.5, SSP3-7.0, SSP5-8.5) Scenario (ScenarioMIP), which is compared with Representative Concentration (RCPs) CMIP5 RCP2.6, RCP4.5, RCP8.5). Furthermore, two large ensembles (LEs) CMIP6 used to investigate effects internal variability projected changes TOE. As shown temporal evolution spatial distribution, strongest warming levels under highest future scenario some follow a “warm-get-warmer” pattern Australia. Over subregions, tropical Australia usually shows warming. Compared RCPs CMIP5, multi-model medians SSPs higher indices commonly exhibit wider spreads, likely related different forcings climate sensitivity subset Based signal-to-noise framework, we confirm that patterns differ greatly extreme uncertainty TOE can result inter-model ranges both signal noise, contributes determination signal. We further demonstrate internally generated variations influence noise. Our findings provide useful information mitigation strategies adaptation planning