After decades of research, the equilibrium climate sensitivity has remained fairly close to 3°C for a doubling of pre-industrial CO₂ concentrations.
carbonbrief.org/explainer-how-…
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1. If the ECS is a (useful) state variable, then it should be robust to data
2. With ~200 years of data, you are smoking something if you can estimate equilibrium >1000+ years ahead. (link.springer.com/article/10.100…)
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To me, it is analogous (& very related) to carbon budgets. Since I think carbon budgets are not that useful for policy (other than an elevator pitch), you can infer what I think of the policy utility of the ECS rdcu.be/OfDv
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