  We propose a statistical emulator for a climate-economy deterministic
integrated assessment model ensemble, based on a functional regression
framework. Inference on the unknown parameters is carried out through a mixed
effects hierarchical model using a fully Bayesian framework with a prior
distribution on the vector of all parameters. We also suggest an autoregressive
parameterization of the covariance matrix of the error, with matching marginal
prior. In this way, we allow for a functional framework for the discretized
output of the simulators that allows their time continuous evaluation.
