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Climate Prediction on Timescales of Seasons to Decades

Climate Prediction on Timescales of Seasons to Decades. A tool for sustainable development in the 21 st Century T N Palmer ECMWF. Increasing levels of CO 2 are changing the probability of occurrence of spells of cold/warm wet/dry weather.

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Climate Prediction on Timescales of Seasons to Decades

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  1. Climate Prediction on Timescales of Seasons to Decades A tool for sustainable development in the 21st Century T N Palmer ECMWF

  2. Increasing levels of CO2 are changing the probability of occurrence of spells of cold/warm wet/dry weather.

  3. Multiple climate forecasts (varying uncertain initial conditions and uncertain model parameters) can be used to estimate the impact of increasing levels of CO2 on the probability of occurrence of drought/flood/heatwave/cold snap.

  4. Ensemble Climate Forecasting • An ensemble is a set of predictions, each member with slightly different initial conditions and using slightly different model approximations. • Ensemble gives - most likely prediction • - estimate of uncertainty • - probability of occurrence of extreme climatic conditions.

  5. Probability of 1-in-20 year warm summer Weisheimer and Palmer, 2005

  6. Probability of 1-in-20 year dry summer

  7. Probability of 1-in-20 year wet summer

  8. Increasing Levels of CO2 are Predicted to Change the Risk of Extreme Seasonal Climate Anomalies. As part of an overall adaptation strategy to lessen the impact of inevitable climate change, particularly in developing countries, the use of climate models to predict risk of particular occurrences of seasonal climatic extremes months to seasons ahead, will be of increasing importance.

  9. El-Niño

  10. Thomson, M.C., Doblas-Reyes, F.J., Mason S.J., Hagedorn, R., Connor S.J., Phindela, T., Morse, A.P. and Palmer, T.N. Malaria early warnings based on seasonal climate forecasts from multi-model ensembles. Nature, 439,576-579.

  11. -- high malaria years -- low malaria years Low malaria incidence High malaria incidence Cumulative PDFs of standardised malaria incidence in Botswana five months in advance of the epidemic

  12. Climatic linkage with meningitis in African Sahel

  13. Webster P.J., Anderson, D.L.T. Chang, H.-R., Grossman, R., Hoyas, C., Hopson, T., Shami, K., Subbiah, A. and Palmer, T.N. Regional application of monsoon dynamics: implementation of a three-tier flood and precipitation forecasting scheme for Bangladesh and surrounding regions. CLIVAR Exchanges, 9, 21-25.

  14. Challinor, A.J., Singo, J.M., Wheeler, T.R. and Doblas-Reyes, F.J., 2005. Probabilistic simulations of crop yield over western India using the DEMETER seaonal hindcast ensembles. Tellus 57A, 498-512.

  15. 12-h development of Hurricane Earl: Sept.1, 1998: 1-km horizontal resolution The LACES ProjectLarge Atmospheric Computation on the Earth Simulator

  16. Conclusions • Increasing levels of CO2 are gradually changing the probability of occurrence of extremes of weather. • Ensemble forecast techniques give probabilistic estimates of climate change. • The same techniques and models can be used to make seasonal climate forecasts - a increasingly valuable tool to help society, especially in developing countries, adapt to the changing risk of climate extremes. • The accuracy of climate forecasts is compromised by inadequate computational resources.

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