Annex 1
ONGOING RESEARCH ON CLIMATE CHANGE
In January 2004, the Environment Agency embarked
on a 3-year programme of targeted research to broaden the range
of functions covered. The aim of the Climatic change impacts and
adaptation research programme (X1-045) is to deliver technical
methods and information that can be used for strategic and operational
assessments of existing standards, regulated activities and the
protection of environments that are potentially impacted by climate
change. Key outcomes of the research will be: information on how
future temperature and precipitation changes and extreme events
will affect water quality and quantity; information and guidance
on future surface runoff and groundwater recharge for evaluation
of strategic water supply; strategic assessments of future land
and air quality, with an emphasis on diffuse pollution; warning
of key impacts to freshwater ecosystems (including possible benefits
for certain types of fisheries and angling activity); advice on
the siting, operations and environmental security of waste management
facilities at risk from flooding.
A key aspect of our Climatic change impacts
and adaptation research programme will be the exploration of a
wider range of climate change uncertainties than those presented
by UKCIP02. Specifically, we will explore the sensitivity of projected
climate change impacts to the choice of emissions, global climate
model and impacts model. We will also provide better characterisations
of long-term natural variability in water supplies, and ecosystem
functioning.
SOURCES OF UNCERTAINTY
Our step-wise framework[7]
for risk-based decision-making distinguishes between climate adaptation
decisions, climate influenced decisions, climate adaptation constraining
decisions, and "no regret" climate adaptation options.
Handling uncertainty is an important part of our risk assessment
processes.
Projections of climate change impacts on water
security are couched within uncertainties about future emissions
of greenhouse gases, imperfect understanding of climate science,
the character of natural variability[8],
and robustness of impacts models.
Despite the immediate divergence of future emissions
in the SRES scenarios, uncertainty in emissions has very little
influence on uncertainty in climate change until the latter half
of the 21st century.
In comparison, model-to-model differences in
climate change projections are large. For example, changes in
winter precipitation over the British Isles by the 2080s under
the SRES A2 emissions scenario ranges between +1% and +61% depending
on the choice of global climate model2. This uncertainty arises
from different treatments of important feedbacks (such as cloud
properties) by different climate models.
Natural variability in the climate system arises
from changes in the output of the sun and the amount of aerosol
injected into the stratosphere by explosive volcanic eruptions.
The climate also varies from year to year and decade to decade
because of the chaotic nature of ocean-atmosphere interactions.
Neither source of natural variability can be predicted for future
decades, but the range of uncertainty can be quantified provided
that we have sufficiently long and representative environmental
records.
Impacts models are widely employed by planners
and engineers to assist strategic decision making. However, the
structure and internal weights of these models are often poorly
specified leading to considerable uncertainty in modelled outcomes.
Novel techniques are required to explore the interplay between
these uncertainties and those linked to choice of emission scenario,
climate model and natural variability[9].
Environment Agency
April 2004
7 Willows, R and Connell, R (Eds) 2003. Climate adaptation:
Risk, uncertainty and decision-making. UKCIP/Environment Agency
Technical Report. UKCIP, Oxford. Back
8
Jenkins, G and Lowe, J 2003. Handling uncertainties in the UKCIP02
scenarios of climate change. Hadley Centre Technical Note 44.
Met Office, Exeter. Back
9
Webster, M, Forest, C, Reilly, J, Babiker, M, Kicklighter, D,
Mayer, M, Prinn, R, Sarofim, M, Sokolov, A, Stone, P and Wang,
C 2003. Uncertainty analysis of climate change and policy response.
Climatic Change, 61, 295-320. Back
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