what is the point of this session? to use the uk’s experience to give ideas about creating and...
TRANSCRIPT
What is the point of this session?• To use the UK’s experience to give
ideas about creating and using climate change scenarios in other countries and situations
• Not a talk on climate modelling!• An overview of who, how, what and
why• Discussion of how these experiences
apply to your own needs
The next hour and a half…..• What are climate change scenarios and how
have they featured in the UK?• How have the “UKCIP02” scenarios been
created?• Who are the major players?• How have we dealt with uncertainties?• Potential applications of the UKCIP02 scenarios• How can the scenarios be improved?• Lessons for the future• Discussion
What are scenarios?
A scenario is: “a coherent, internally consistent and
plausible description of a possible future state of the world” (Parry and
Carter, 1998)
Not a forecast or a prediction A series of pictures of what the world
could look like in the future
Climate change scenarios• Socio-economic futures (eg.
population, economy, carbon intensity) - affects how GHG may change
• Climate modelling• Result: integrated scenarios -
more sophisticated than pure climate modelling
A history of UK Climate Change scenarios• Climate Change Impacts Review
Group of the DoE (CCIRG)• 1991, 1996• Presented a range of highly artificial
global-scale scenarios (CO2 doubling)
• Tended to present a ‘best guess’ based on 1980s Met Office UKTR model and HadCM1
The 1998 UKCIP scenarios• 1997: UK Climate Impacts Programme
(UKCIP)• 1998: Climatic Research Unit, Hadley
Centre created UKCIP98 scenarios• Wider range of variables and time-scales
than CCIRG• Range of four scenarios based on
IS92a/IS92d• HadCM2 model
UKCIP02 Climate Change Scenarios
• Mike Hulme• Xianfu Lu• John Turnpenny• Tim Mitchell
• Geoff Jenkins• Richard Jones• Jason Lowe• James Murphy• David Hassell• Penny Boorman• Ruth McDonald• Steven Hill
The UKCIP02 Scenarios
• To be launched April 2002 • Revised scenarios using developments
over past three years• Explicitly linked to four socio-economic
scenarios produced by IPCC• Informed by the Third IPCC Climate
Change Assessment Report
• Uses more sophisticated HadCM3 and regional HadRM3 models (more greenhouse gas species, improved ocean and vegetation models)
• Much more detailed regional information (104 vs. 4 grid boxes)
• 5 km observed data set• Responses to users: much more on
extremes; rapid climate change; Gulf Stream; uncertainty
The SRES Scenarios
Storyline Description
A1 Very rapid economic growth; population peaks mid-century; social, cultural andeconomic convergence among regions; market mechanisms dominate. Subdivisions:A1FI – reliance on fossil fuels; A1T – reliance on non-fossil fuels; A1B – a balance
across all fuel sources A2 Self-reliance; preservation of local identities; continuously increasing population;
economic growth on regional scales B1 Clean and efficient technologies; reduction in material use; global solutions to
economic, social and environmental sustainability; improved equity; population peaksmid-century
B2 Local solutions to sustainability; continuously increasing population at a lower ratethan in A2; less rapid technological change than in B1 and A1
The four UKCIP02 scenarios• High Emissions A1FI• Medium-High Emissions A2• Medium-Low Emissions B2• Low Emissions B1
as inputs to Hadley Centre’s HadCM3 model (effective sensitivity 3.0 deg C)
The Hadley Centre Global Climate Model (HadCM3)
19 levels in
atmosphere
20 levels
in ocean
2.5lat 3.75
long
1.25 km
1.25 km
300 km
-5km
What are UKCIP02’s defining characteristics?• It was GENERIC rather than for a
SPECIFIC impacts project• The centre of a policy network of
groups with different aims• Scenario range examined
emissions uncertainty rather than uncertainty in the model
What do the key players represent?• DEFRA - funder; government policy;
international obligations; public perception
• UKCIP - scenario users (scientists, policymakers, impact assessments)
• Hadley - rigorous science basis of climate modelling
• Tyndall - leading the analysis and writing; coordinating report production
The results
• UKCIP02 had to balance needs of all the organisations
• Ease of communication vs. rigorous science vs. usefulness to impacts community
• Example - pattern-scaling
Pattern-scaling
• Only A2 emissions, 2071-2100 means were modelled
• Other time periods and emissions scenarios were produced by ‘scaling’ the model output patterns
• Scientifically less than rigorous• But needed by the users (eg 2020s,
2050s)
Interaction with other groups
• Hadley Centre modellers - storm surges/ocean modelling
• Land movement (Durham)• Sea level (POL)
What uncertainties are there?• Emissions - how will society change?
We chose to explicitly include these in the range of scenarios
• Scientific - how do different models represent the environment? We have assessed the main scientific uncertainties and provided guidance on how to incorporate these
Pattern-scaling
• Scientifically acceptable to scale HadRM3 patterns with other models’ global temperatures? We decided not.
• Acceptable comparison between model and pattern-scaled results? Yes.
Stakeholder Decision Scenario Requirements UKCIP StudyCountryside andconservationmanagers
Evaluating and managing achanging naturalenvironment
Guided sensitivity analysiscombining historical variationsin climate with future changes inclimate under a range ofscenarios
MONARCH
Regional land useplanners
How to assess relativevulnerability and plan forchange across differentsectors
Regional scenarios with a widerange of climate outputs
Sub-UK andregionalassessments
Regional coastaland flood defencemanagers
Developing a riskassessment for a coastal“cell” or river catchment
Geographically explicitscenarios, showing thelikelihood of changes in extremeweather events
RegIS
Water resourcemanagers
Evaluation of the futurewater supply/demandbalance and whether to planfor new resources
Regional scenarios with explicitprobability assessment; returnperiod of extreme weather events
CD:DEW
Questions for discussion• Who are your scenarios for?• Who is funding them?• How will they link climate and social science?• Who is the most important player?• How might the different powers interact?• How will you communicate them to relevant
groups and to the public?• Are they ‘user-friendly’?• Which government department is responsible, if
any?