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Some thoughts on guidelines for the appropriate use of climate scenarios in climate assessments intended to inform policy
Some thoughts on guidelines for the appropriate use of climate scenarios in climate assessments intended to inform policy
Any scenario that is used to project a future deemed plausible needs to be justified explicitly in terms of plausibility
Presently this is almost never done
Here is an example of a plausibility analysis: cliccs.uni-hamburg.de/results/hambur…
Here is another: osf.io/preprints/soca…
Presently this is almost never done
Here is an example of a plausibility analysis: cliccs.uni-hamburg.de/results/hambur…
Here is another: osf.io/preprints/soca…
The language of scenarios lends itself to confusion
scenarios can be inputs or outputs
scenario outputs can be pathways
pathways can result from many scenarios
Precision in language is needed, not for standardization, but for simple communication
scenarios can be inputs or outputs
scenario outputs can be pathways
pathways can result from many scenarios
Precision in language is needed, not for standardization, but for simple communication
There are 1000s of climate scenarios
Only a handful are used in climate research
If the use of a scenario in assessment is "because that is what is available" then problems can result
Scenarios from 2011, 2005 and earlier are now dated
Only a handful are used in climate research
If the use of a scenario in assessment is "because that is what is available" then problems can result
Scenarios from 2011, 2005 and earlier are now dated
Don't use implausible scenarios
eg, RCP8.5, SSP3-7.0, SSP5-8.5, RCP6.0
If you want to explore implausible futures, great, do so in an assessment chapter titled "Exploration of Implausible Futures" so policy makers don't confuse the implausible with the plausible
eg, RCP8.5, SSP3-7.0, SSP5-8.5, RCP6.0
If you want to explore implausible futures, great, do so in an assessment chapter titled "Exploration of Implausible Futures" so policy makers don't confuse the implausible with the plausible
Expect some consistency in assessment
The US NCA uses RCP4.5 as a scenario of policy success
The UK CCRA3 uses RCP4.5 to represent current policies
Our research suggests it is closer to a worst case
Which is it?
Maybe worth a discussion
The US NCA uses RCP4.5 as a scenario of policy success
The UK CCRA3 uses RCP4.5 to represent current policies
Our research suggests it is closer to a worst case
Which is it?
Maybe worth a discussion
Expect that scenarios will become dated and no longer plausible
Hey, that's good news
Climate policy, by definition, will make extreme scenarios increasing implausible. That's the point.
So prepare yourself for a time (now?) when most or all extreme scenarios are implausible
Hey, that's good news
Climate policy, by definition, will make extreme scenarios increasing implausible. That's the point.
So prepare yourself for a time (now?) when most or all extreme scenarios are implausible
Expect scenarios & their application to be rigorously evaluated by people in & out the core climate scenario building community
That is healthy & good for science
People will have different views on plausibility, evidence, and the future - that is a feature of scenario planning
That is healthy & good for science
People will have different views on plausibility, evidence, and the future - that is a feature of scenario planning
Finally for now
Recognize scenarios are always normative
We use scenarios to steer towards desirable futures & away from the undesirable
But what is un/desirable is abt values
How to get there is abt values
What variables to look at is abt values
Values conflict means politics
Recognize scenarios are always normative
We use scenarios to steer towards desirable futures & away from the undesirable
But what is un/desirable is abt values
How to get there is abt values
What variables to look at is abt values
Values conflict means politics
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