final_program_abstracts[1]

11 IMSC Session Program
The potential to narrow uncertainty in regional climate
predictions
Friday - Parallel Session 1
Ed Hawkins and Rowan Sutton
NCAS - Climate, University of Reading, Reading, UK
Faced by the realities of a changing climate, decision makers in a wide variety of
organisations are increasingly seeking quantitative predictions of regional and local
climate. An important issue for these decision makers, and for organisations that fund
climate research, is what is the potential for climate science to deliver improvements -
especially reductions in uncertainty - in such predictions?
Uncertainty in climate predictions arises from three distinct sources: internal
variability, model uncertainty and scenario uncertainty. Using data from a suite of
climate models (CMIP3), we separate and quantify these sources for predictions of
both surface air temperature and precipitation.
For predictions of changes in temperature on decadal timescales and regional spatial
scales, we show that uncertainty for the next few decades is dominated by sources
(model uncertainty and internal variability) that are potentially reducible through
progress in climate science. Furthermore, we find that model uncertainty is of greater
importance than internal variability. For precipitation projections we find that the
potential to narrow uncertainty is far lower than for temperature. We also consider the
sources of uncertainty in predictions of stratospheric ozone recovery and Amazonian
dieback.
Our findings have implications for managing adaptation to a changing climate.
Because the costs of adaptation are very large, and greater uncertainty about future
climate is likely to be associated with more expensive adaptation, reducing
uncertainty in climate predictions is potentially of enormous economic value. Our
study also highlights the importance of targeting climate science investments on the
most promising opportunities to reduce prediction uncertainty.
For more details:
Hawkins & Sutton, 2009, BAMS, 90, p1095
Hawkins & Sutton, 2010, Climate Dynamics, in review
Abstracts 359