sres approach to scenario formation
DESCRIPTION
SRES Approach to Scenario Formation. Linda O. Mearns NCAR/ICTP. GECAFS Meeting Reading, UK August 2003. Intergovernmental Panel on Climate Change (IPCC). Established by WMO and UNEP in 1988 Purpose: to assess the scientific and socio-economic information regarding climate change - PowerPoint PPT PresentationTRANSCRIPT
SRES Approach to Scenario Formation
Linda O. Mearns
NCAR/ICTP
GECAFS Meeting
Reading, UK
August 2003
Intergovernmental Panel on Climate Change (IPCC)
• Established by WMO and UNEP in 1988
• Purpose: to assess the scientific and socio-economic information regarding climate change
• The IPCC has three Working Groups:
•Working Group I: Science of the climate system
•Working Group II: Impacts, vulnerability and adaptation
•Working Group III: Options for limiting greenhouse gases
• There have been three full assessments: 1990, 1995, 2001
Purpose of Scenarios
• WGI - provide emissions scenarios for driving Atmosphere-Ocean GCMs
• WGII – provision of climate change scenarios, and background scenario information (demographics, economic conditions, technology) for determining impacts of climate change on various resource systems.
• WGIII - need information on socio-economic settings for determining potential mitigation policy/strategies
Basis of Scenarios
• Extensive assessment of driving forces and emissions in the scenario literature, alternative modeling approaches, and an “open process’’ that solicited wide participation and feedback.
• Open process refers to use of multiple models, seeking inputs from wide community, and making results widely available for comment and review. There was an open SRES website.
Basis 2
• No preference provided for any one scenario, not assigned probability of occurrence, not to be taken as policy recommendations
• Do not include assumption of implementation of UNFCCC or targets of the Kyoto Protocol
Process of Scenarios Development
• Four qualitative story lines developed Basic features and driving forces • Teams modeled and quantified different
storylines • Resulted in the 40 emissions scenarios • Six IA type models used to generate the
scenarios: Asian Pacific Integrated Model (AIM);
Atmospheric Stabilization Framework (ASF);
Development 2
• Models (cont’d): Integrated Model to Assess the Greenhouse
Effect (IMAGE); Multiregional Approach for Resource and
Industry Allocation (MARIA); Model for Energy Supply Strategy
Alternatives and their General Environmental Impact (MESSAGE);
Mini Climate Assessment Model (MiniCAM)
Main Scenario Driving Forces
• Population - exogenous input to models
7-15 billion by 2100
• Economic Development - US$197-550
trillion by 2100 (gross world product)
• Structural and Technological Change –
represented by energy and land use
Four Macro-regions
• OECD90 – countries belonging to OECD (Annex I countries), developed
• REF - countries undergoing economic reform – Eastern Europe and FSU
• ASIA – all developing countries in Asia
• ALM – all other developing countries, Latin America, Africa, Middle East
SRES Emissions ScenariosThe Four Major Story Lines
• A1 – characterized by very rapid economic growth, global population peaking in mid-century, and then declining, and rapid introduction of new, efficient technologies. Three different subgroups in the A1 storyline are defined that present alternative changes in technology: fossil intensive (A1FI), non-fossil (A1T) and balanced across sources (A1B).
• A2 – characterized by heterogeneity. Self reliance and local identities are emphasized. Population increases continuously. Economic development is regionally oriented, and economic and technological growth is relatively slow, compared to other storylines.
• B1 – a convergent world, having the population growth of the A1 story line. Economic structures change rapidly toward a service and information economy, clean and resource-efficient technologies are introduced, with emphases on social and environmental sustainability.
• B2 – local solutions to economic, social and environmental sustainability is emphasized. Global population grows continuously, but at rate lower than that of A2.
IMAGE 2.2 - 1970 Land Cover
IMAGE 2.2 Land Cover Types
0 - Ocean
1 - Agriculture
2 - Extensive grassland
3 - C plantation - NU
4 - Regrowth (abandon)
5 - Regrowth (timber)
6 - Ice
7 - Tundra
8 - Wooded Tundra
9 - Boreal Forest
10 - Cool Conifer
11 - Temperate Mixed Forest
12 - Temperate Decid Forest
13 - Warm Mixed Forest
14 - Grass/Steppe
15 - Desert
16 - Scrubland
17 - Savanna
18 - Tropical Woodland
19 - Tropical Forest
No Data
IMAGE 2.2 - A2: 2100 Land Cover
IMAGE 2.2 Land Cover Types
0 - Ocean
1 - Agriculture
2 - Extensive grassland
3 - C plantation - NU
4 - Regrowth (abandon)
5 - Regrowth (timber)
6 - Ice
7 - Tundra
8 - Wooded Tundra
9 - Boreal Forest
10 - Cool Conifer
11 - Temperate Mixed Forest
12 - Temperate Decid Forest
13 - Warm Mixed Forest
14 - Grass/Steppe
15 - Desert
16 - Scrubland
17 - Savanna
18 - Tropical Woodland
19 - Tropical Forest
No Data
1990 2000 2010 2020 2030 2040 2050 2060 2070 2080 2090 2100
3000
2500
2000
1500
1000
500
0
Tot
al C
umul
ativ
e C
arb
on D
ioxi
de E
mis
sion
s (G
tC)
Cumulative Emission 1990-2100, CtC
High > 1800 GtC
Medium High 1450-1800 GtC
Medium Low 1100-1450 GtC
Low < 1100 GtC
A1F1
A2
A1B
B2A1T
B1
IS92 Range
AOGCM Simulations
Change in Sea Level Rise
Spatial Scale of Uncertainty
T
P
T
?P
T
??P
Uncerta
inty
Projections of Future Climate
Downscaling the SRES Scenarios
TGCIA Activities
Moving from aggregate to decision-maker relevant
scales
• SRES reported data on the level of the 4 macro-regions
• Many of the IA models produced results at higher resolutions
CIESEN has collected high res. data – and made it available • CIESEN also formally downscaled
socio-economic data to nation level
Plans for Next IPCC Assessment
IPCC: 2002 to 2007
• 3 Working groups maintain same scope as in last 5 years:– WG1: Physical climate system– WG2: Impacts and Adaptation– WG3: Mitigation
• Fourth Assessment Report (AR4) to be completed in 2007
• Planning and scoping: 2003, 2004Drafting and reviewing: 2005, 2006.
IPCC AR4: Proposed Themes
• More careful approach to describing uncertainties - consistent across WGs
• Integrating mitigation and adaptation• Identifying key vulnerabilities in regions
and systems• Putting climate change in the context of
sustainable development• Adopting a consistent regional approach
across WGs.
IPCC WG1: Likely issues (1)
• Avoiding the “tyranny of the global mean” – greater regional focus
• Updating climate change scenarios for impact studies (particularly for vulnerable regions: polar, monsoon, coral reefs,… )
• New focus on Climate – Water issues• Climate Sensitivity – how do we reduce the
1.5oC to 4.5oC range !
IPCC WG1: Likely issues (2)
• Emission scenarios– rely mainly on existing scenarios, but…– black carbon emissions– climate change feedbacks on natural emissions– harmonizing SRES scenarios with the 1990 –
2005 period
• Direct influence of aerosols on the hydrological cycle