Lisø PhD Dissertation Manuscript - NTNU

Lisø, K.R./ Building envelope performance in harsh climates: Methods for geographically dependent design
technical, economic and social opportunities of these mitigation options (Metz et al.,
2001).
Global warming will lead to changes in the local climate in Norway in this century.
Climate scenarios for Norway emanating from the project “Regional climate
development under global warming” (RegClim) suggest changes in mean and
extreme values of temperature, precipitation and wind. The most realistic scenarios
for changes in global climate are based on Atmosphere-Ocean General Circulation
Models, AOGCM’s (Houghton et al., 2001). These global climate models are “fully
coupled, mathematical, computer-based models of the physics, chemistry and
biology of the atmosphere, land surface, oceans and cryosphere and their interaction
with each other and with the sun and other influences like e.g. volcanic eruptions”
(Karl and Trenberth, 2003). The spatial resolution in the recent AOGCMs is still too
coarse to enable these global climate models to reproduce the climate on regional or
local scale. To deduce detailed scenarios for future climate development in different
parts of Norway, both dynamic and empirical downscaling techniques are being
applied on integrations with global climate models. The downscaled scenarios
indicate a general increase in temperature and precipitation rates across the country
(see e.g. Paper II; Benestad, 2005). Consistent with emerging global patterns, the
projected temperature increases are at a maximum during the winter and at a
minimum during the summer and warming rates increase from south to north and
from coast to inland. Precipitation scenarios suggest increased precipitation in
existing wet areas and periods, in agreement with scenarios at the global scale.
Extreme amounts of precipitation will appear more often in all of Norway. The
RegClim scenarios also suggest a moderate increase in wind in the southernmost
areas and along the coast of Central Norway, with most of the increase manifesting
itself during the autumn and winter months.
The climate is a product of both ordered forcing and chaotic behaviour (Rind, 1999).
Several sources of uncertainties exist related to both scenarios for global climate
change, and to the effects of global warming on regional-level climate. The regional
scenarios should not be considered as forecasts in an absolute sense. They offer
insights into the likely range and nature of future weather scenarios. The regional
scenarios for climate change are continuously being improved, increasing their
reliability along with knowledge on uncertainties connected with inaccurate climate
models, random climate variations and different downscaling techniques.
The possible effects of climate change, and the subject of risk management,
adaptation and mitigation, are now being addressed in several parts of the world.
Challenges confronting the built environment in responding to the potential impacts
of climate change were one of the main themes in a special issue of Building
Research & Information in 2003 (Paper I; Sanders and Phillipson, 2003; Shimoda,
2003; Larsson, 2003; du Plessis et al., 2003; Mills, 2003; Hertin et al., 2003;
Steemers, 2003).
The amount of building defects in Norway (see Section 1.5) clearly illustrates that it
is not only the extreme weather events that need to be studied as a foundation for
long-term adaptation towards a changing climate. A well-functioning and reliable
infrastructure is an important basis for economic growth and social development.
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