{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"f8b4a0f728133fe2559e66b2b6af94e564012abc2f2cb99e464bd379596a1104","created":"2026-10-15T23:43:22Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["0c7c9ed5e2d8fd1bd3bece5152d8c6e1a644e52fc34fec7edad9f38e0680915e","ce59fb6cd812fc05906d0c60a71c75ea22bc686bcf38e7c3ef7010834d98ee7b"],"salt":"b1141bc54afe25b78c89a9c302aa7e408a409d95daf5f44b875ddd4347d58c5f","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":[],"external_id":"earth.climate-sensitivity.ecs-value","kind":"well-posed","literature_status":"partially-resolved","n":"2","parents":[],"plain":"Doubling $\\mathrm{CO_2}$ will warm Earth by somewhere around 2.5 to 4 degrees once the oceans catch up. Narrowing that range has proved hard for decades.","posed_since":"1896","precise":"Equilibrium climate sensitivity (ECS) is the equilibrium global-mean surface air temperature change for doubled $\\mathrm{CO_2}$ (forcing about $4\\mathrm{e}3\\,\\mathrm{erg}/(\\mathrm{s}\\,\\mathrm{cm}^{2})$). The 2020 multi-evidence assessment gives a 66 percent range of about $2.6\\ \\text{to}\\ 3.9\\,\\mathrm{K}$ and the 2021 IPCC assessment a likely range of $2.5\\ \\text{to}\\ 4\\,\\mathrm{K}$. An answer is a 66 percent range narrower than $1\\,\\mathrm{K}$ consistent with process, historical and paleoclimate evidence.","problem_ref":"0c7c9ed5e2d8fd1bd3bece5152d8c6e1a644e52fc34fec7edad9f38e0680915e","references":"","settled_by":"Process-level constraints on cloud feedbacks combined with paleoclimate and historical energy-budget estimates that agree within a sub-kelvin range.","status_note":"","title":"What is Earth's equilibrium climate sensitivity?","topic_ref":null},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"5ae6c30fda26cc7fa9a47a014b02bdd6ddb0ef48ad5860a98ac77a0d99f93e0d","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"c41a6da05163796127f572db5e037d155b74d0f3c1ef1cc00ada6f8506e1ecfc","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"dfFyMC3Ukr6RBul4s2nUoL50-IAXAGjxwLadkDoueDtN7LSw1OaU_i3MinG6Zit3ERpQOE5vB4WJOHsaIpuUDw"},"schema":"pubphys.envelope/1"},"record_hash":"5ae6c30fda26cc7fa9a47a014b02bdd6ddb0ef48ad5860a98ac77a0d99f93e0d","leaf_index":3174}