London scoping - ukcip

Sea level
Source: IPCC (2001a)
Final Report
43
Tide gauge data show that global average sea level rose between 0.1 and 0.2 metres
during the 20 th century.
Global sea level is projected to rise by 0.09 to 0.88 metres between 1990 and 2100,
for the full range of SRES scenarios.
Table 4.3 Estimates of confidence for selected observed and projected changes in extreme
weather and climate events
Changes in phenomenon Confidence* in observed
changes (latter half of 20th
century)
Higher maximum temperatures
and more hot days over nearly all
land areas
Higher minimum temperatures,
fewer cold days and frost days
over nearly all land areas
Reduced diurnal temperature
range over most land areas
Increase of heat index over land
areas
Likely Very likely
Very likely Very likely
Very likely Very likely
Confidence* in projected
changes (during the 21st
century)
Likely, over many areas Very likely, over most areas
More intense precipitation events Likely, over many NH land areas Very likely, over many areas
Increased summer continental
drying and associated risk of
drought
Likely, in a few areas Likely, over most mid-latitude
continental interiors
* IPCC qualitative classification of confidence levels: Likely (66 to 90%), Very likely (90 to 99%)
Source: IPCC (2001a)
4.3 Climate Change Scenarios for the UK and London
Since the publication of the UKCIP98 scenarios (Hulme and Jenkins, 1998), significant
advances in computing power have enabled a greater number of climate model experiments to
be conducted at higher spatial resolutions. The Hadley Centre global climate model (HadCM3)
was used to drive a high resolution atmospheric model (HadAM3H) and, in turn, a regional
climate model (HadRM3) for Europe. These experiments resulted in the development of the
UKCIP02 scenarios (Hulme et al., 2002) which describe how the climate of the UK land area
may change in the 21 st Century at a resolution of ~50 km (as opposed to the ~300 km resolution
of UKCIP98). The new scenarios also provide more information about changes in extremes of
weather and sea level, and are explicitly linked to the four SRES storylines described in
Table 2.1 (B1~Low Emissions, B2~Medium-Low Emissions, A2~Medium-High Emissions,
A1F1~High Emissions). In contrast, the UKCIP98 scenarios were based on much simpler
descriptions of future population and fossil fuel use.