Claudia Tebaldi (Climate Central & NCAR) gives a talk at the 6th Munich-Sydney-Tilburg Conference on "Models and Decisions" (10-12 April, 2013) titled "Making sense of multiple climate models' projections". Abstract: In the last decade or so the climate change research community has adopted multi-model ensemble projections as the standard paradigm for the characterization of future climate changes. Why multiple models, and how we reconcile and synthesize -- or fail to -- their different projections, even under the same scenarios of future greenhouse gas emissions, will be the themes of my talk. Multi-model ensembles are fundamental to exploring an important source of uncertainty, that of model structural assumptions. Different models have different strength and weaknesses, and, how we use observations to diagnose those strengths and weaknesses, and then how we translate model performance in a measure of model reliability, are currently open research questions. The inter-dependencies among models, the existence of common errors and biases, are also a challenge to the interpretation of statistics from multi-model output. All this constitutes an interesting research field in the abstract, whose most current directions I will try to sketch in my talk, but is also critical to understand in the course of utilizing model output for practical purposes, to inform policy and decision making for adaptation and mitigation.