Transcript actual infinity

Scenario process
Next steps
New scenarios
(Share Socio-economic
Pathways)
New scenarios
(Share Socio-economic
Pathways)
Scale issues
Using these global
scenarios to build local
scenarios and analyze
actual decisions
New scenarios
(Share Socio-economic
Pathways)
Scale issues
Using these global
scenarios to build local
scenarios and analyze
actual decisions
Content issues
Define/refine scenarios to
make them appropriate for
various decisions
New scenarios
(Share Socio-economic
Pathways)
Scale issues
Using these global
scenarios to build local
scenarios and analyze
actual decisions
Content issues
Define/refine scenarios to
make them appropriate for
various decisions
Relevance issues
Determine what scenarios
are most relevant for a
given question
Input for new generation
through aggregation
New scenarios
(Share Socio-economic
Pathways)
Input for new generation
Scale issues
Using these global
scenarios to build local
scenarios and analyze
actual decisions
Content issues
Define/refine scenarios to
make them appropriate for
various decisions
Relevance issues
Determine what scenarios
are most relevant for a
given question
Scale issues
From global scenarios to local
decisions
• Most decisions require local-scale scenarios:
– Health effects of local pollution depends on
transportation, which in turn depends on:
• local choices (e.g., urban sprawl policy)
• global choices (e.g, oil price, availability of electric cars)
– Natural disaster impacts depends on
infrastructure, which in turn depends on:
• local choices (e.g., do we build dikes?)
• global choices (e.g., what foreign aid to build
infrastructure?)
Global scenarios as boundary
conditions
• Global scenarios = boundary conditions for local
scenarios
• No automatic and deterministic link between global
and local scenarios, but a set of constraints:
– a local scenario with local degradation in governance
quality is consistent with a global scenario with improved
governance
– a local scenario with 100% electric cars is not consistent
with a global scenario without electric cars.
Global vs. local scenarios
Global vs. local scenarios
Step 1: Defining global scenarios
Global vs. local scenarios
Step 1: Defining global scenarios
Step 2:
Downscaling from
global scenario to
local scenario
Scenario for
urban extension
in Paris up to
2100
Global vs. local scenarios
Step 1: Defining global scenarios
Step 2:
Downscaling from
global scenario to
local scenario
Scenario for
urban extension
in Paris up to
2100
Step 3
Aggregation of
many local
scenarios into new
global scenarios?
Content issues
Scenario variables for health issues?
• In the previous generation of scenarios, many variables
were missing for relevant health issues:
– Nothing on inequality within countries
– Nothing on governance and development of health
insurance
–…
• In the new generation, “extended” Share
Socioeconomic Pathways to include more variables:
– Work is needed to identify what is required
– Work is needed to create the corresponding quantitative
or qualitative information
Relevance issues
Relevant scenarios for one questions
• An infinity of possible futures…
• … but practical reasons to have only a small
set of scenarios
• We will have 5 Shared SocioEconomic Pathway
(SSP).
• These SSPs have been chosen to inform most
decisions on mitigation and adaptation.
From many possible futures…
… selection of a few representative ones
CO2 emissions in the baseline
Depending on how we define our
indicators of capacity to adapt
and capacity to mitigation, the
distribution of scenarios is
different
in baseline
Emission
baseline
in the
CO2 emissions
Depending on how we define our
indicators of capacity to adapt
and capacity to mitigation, the
distribution of scenarios is
different
GDP per capital of the 20% poorest in a selection of
developing countries
in baseline
Emission
baseline
in the
CO2 emissions
Depending on how we define our
indicators of capacity to adapt
and capacity to mitigation, the
distribution of scenarios is
different
GDP cost to reach 550ppm
GDP per capital of the 20% poorest in a selection of
developing countries
Share of agriculture in GDP
in baseline
Emission
baseline
in the
CO2 emissions
Depending on how we define our
indicators of capacity to adapt
and capacity to mitigation, the
distribution of scenarios is
different
Ideally, we would have different
SSPs for each research question
or policy analysis
Toward a large dataset of
scenarios?
GDP cost to reach 550ppm
GDP per capital of the 20% poorest in a selection of
developing countries
Share of agriculture in GDP
Relevant scenarios for one questions
• We will have 5 Shared SocioEconomic Pathway (SSP).
• These SSPs have been chosen to inform most decisions on mitigation
and adaptation.
• But certain decisions will require different scenarios:
– To work on water-borne illness, having scenarios that differ by the oil
price may be useless.
– To work on local air pollution in cities, it is critical to have varying
assumptions on oil price.
• Long-term objective: a large dataset of scenarios and a process to
select a set of few scenarios for each decision or research question
• Question: for various health issues, what differences across
scenarios do we need to perform an unbiased sensitivity analysis?
–
–
–
–
Differences in demographics (aging)
Differences in economic conditions (income, job)
Differences in access to services (drinking water)
Should they be correlated?
Input for new generation
through aggregation
New scenarios
(Share Socio-economic
Pathways)
Input for new generation
Scale issues
Using these global
scenarios to build local
scenarios and analyze
actual decisions
Content issues
Define/refine scenarios to
make them appropriate for
various decisions
Relevance issues
Determine what scenarios
are most relevant for a
given question