cc: j.turnpenny@uea.ac.uk
date: Mon Mar 11 17:51:39 2002
from: Mike Hulme <m.hulme@uea.ac.uk>
subject: unresolved issue
to: wilkins_diana,jenkins_geoff

   Diana and Geoff,
   There is one issue remaining unresolved re. the Briefing Report.  This concerns the Box on
   p.13 about levels of confidence.
   - DEFRA/UKCIP want the box, ideally to also include statements with M and L status also.
   - Hadley don't think it really works unless DIRECTION is included
   Tyndall therefore suggest the version below (there is just not space to include M and L
   statements and remember, we spent a lot more time on this than in the UKCIP98 version
   (p.57) which was highly arbitrary.  If we cannot get agreement the demands of space would
   suggest we drop it!
   We have negotiated an extra 24 hours with the designers so please let me have your views
   Tuesday.
   Mike
   ____________________________________________________

                                      Levels of confidence

   In the scientific report for the UKCIP02 scenarios we adopt a scale of relative confidence
   High, Medium and Low  when presenting summary statements about future changes in UK
   climate.  These are expert judgements made by the authors based on our understanding of the
   physical reasoning involved, consistency between models and statistical significance of the
   results.    It should be emphasised that these are relative rather than absolute
   judgements.  We summarise here the statements regarding the direction of change in which we
   have High Confidence (annual results unless stated):
   Average temperature increases
   Summer temperature increases more in the southeast than the northwest
   High temperature extremes increase in frequency
   Low temperature extremes decrease in frequency
   Sea-surface temperature warms
   Thermal growing season lengthens
   Heating degree days reduce
   Cooling degree days increase
   Winter precipitation increases
   Winter precipitation intensity increases
   Snowfall decreases
   Summer soil moisture decreases
   Specific humidity increases
   Sea-level rises
