TY - JOUR

T1 - Validation and forecasting accuracy in models of climate change

AU - Fildes, Robert

AU - Kourentzes, Nikolaos

PY - 2011/10

Y1 - 2011/10

N2 - Forecasting researchers, with few exceptions, have ignored the current major forecasting controversy: global warming and the role of climate modelling in resolving this challenging topic. In this paper, we take a forecaster’s perspective in reviewing established principles for validating the atmospheric-ocean general circulation models (AOGCMs) used in most climateforecasting, and in particular by the Intergovernmental Panel on ClimateChange (IPCC). Such models should reproduce the behaviours characterising key model outputs, such as global and regional temperature changes. We develop various time series models and compare them with forecasts based on one well-established AOGCM from the UK Hadley Centre. Time series models perform strongly, and structural deficiencies in the AOGCM forecasts are identified using encompassing tests. Regional forecasts from various GCMs had even more deficiencies. We conclude that combining standard time series methods with the structure of AOGCMs may result in a higher forecastingaccuracy. The methodology described here has implications for improving AOGCMs and for the effectiveness of environmental control policies which are focussed on carbon dioxide emissions alone. Critically, the forecast accuracy in decadal prediction has important consequences for environmental planning, so its improvement through this multiple modelling approach should be a priority.

AB - Forecasting researchers, with few exceptions, have ignored the current major forecasting controversy: global warming and the role of climate modelling in resolving this challenging topic. In this paper, we take a forecaster’s perspective in reviewing established principles for validating the atmospheric-ocean general circulation models (AOGCMs) used in most climateforecasting, and in particular by the Intergovernmental Panel on ClimateChange (IPCC). Such models should reproduce the behaviours characterising key model outputs, such as global and regional temperature changes. We develop various time series models and compare them with forecasts based on one well-established AOGCM from the UK Hadley Centre. Time series models perform strongly, and structural deficiencies in the AOGCM forecasts are identified using encompassing tests. Regional forecasts from various GCMs had even more deficiencies. We conclude that combining standard time series methods with the structure of AOGCMs may result in a higher forecastingaccuracy. The methodology described here has implications for improving AOGCMs and for the effectiveness of environmental control policies which are focussed on carbon dioxide emissions alone. Critically, the forecast accuracy in decadal prediction has important consequences for environmental planning, so its improvement through this multiple modelling approach should be a priority.

KW - Validation

KW - Long range forecasting

KW - Simulation models

KW - Global circulation models

KW - Neural networks

KW - Environmental modelling

KW - DePreSys

KW - Encompassing

KW - Decadal prediction

U2 - 10.1016/j.ijforecast.2011.03.008

DO - 10.1016/j.ijforecast.2011.03.008

M3 - Journal article

VL - 27

SP - 968

EP - 995

JO - International Journal of Forecasting

JF - International Journal of Forecasting

IS - 4

ER -