final_program_abstracts[1]

11 IMSC Session Program
Forecast encompassing testing of statistical time series
climate forecasts of global temperature and their implications
for global circulation models
Thursday - Parallel Session 2
Robert Fildes and Nikos Kourentzes
Lancaster Centre for Forecasting, Lancaster University, UK
This paper first considers the validation of long term climate global circulation
models as used by the IPCC in their forecasts of global warming. This paper presents
an appraisal of various extrapolative time series benchmarks forecasts of annual
average temperature, both global and local. Methods include non-linear univariate
neural nets and benchmark smoothing models. Nonlinear multivariate models relating
carbon emissions to globally averaged atmospheric carbon dioxide are also
considered. These models are compared for their accuracy against 10-year ahead
forecasts produced from a global circulation model. By examining forecast
encompassing tests it is shown that the global circulation model is mis-specified and
its forecasts can be improved on by including forecasts from the time series models.
20-year ahead forecasts are improved by including information on CO2 emissions.
Abstracts 242