Emergent constraints on climate sensitivities

Emergent constraints (ECs) relate observables of the climate system to equivalent quantities simulated from Earth models that are related properties future climate. The uncertainties in projections these may be reduced by constraining modeled observables. article examines how such relationships emerge models, simple theories for ECs can derived temporal variability system, and might misinterpreted. A wide range discovered so far presented as well a framework quantifying multiple sources uncertainty ECs. An outlook reducing quantify global environmental change is also given.