He gave an 80% probability that by 2023 the Paris Agreement would still be in effect, with most countries generally making a good-faith effort to comply.

Judge the predicted outcome as of 2023 (the five-year horizon). Two conditions must both hold: (a) the Paris Agreement was still in force as an international treaty; (b) most parties were generally making a good-faith effort to comply, meaning they submitted or updated their nationally determined contributions and took part in the reporting process, not necessarily meeting their targets. True: both hold. Mostly true: both hold but with a minor caveat, such as a temporary withdrawal by one major party that was later reversed by 2023. Mixed: the agreement was in force but a large share of parties (around half) clearly stopped engaging or abandoned their commitments. Mostly false: the agreement was formally in force but most parties had in effect abandoned compliance. False: the agreement was no longer in effect in 2023. Also confirm from the source (the February 2018 Slate Star Codex predictions post) that he gave this 80% probability. If he did not, the claim is false regardless of the outcome.

Set before the research began.

1. E1 2023 NDC Synthesis Report | UNFCCC UNFCCC secretariat · 14 November 2023

   “This version of the NDC synthesis report synthesizes information from the 168 latest available NDCs, representing 195 Parties to the Paris Agreement”

2. E2 2023 NDC Synthesis Report | UNFCCC UNFCCC secretariat · 14 November 2023

   “A total of 20 Parties have communicated new or updated NDCs since 22 September 2022 (the cut-off date for submissions covered in the previous version of this report).”

3. E3 [PDF] FCCC/SBI/2024/9 - UNFCCC UNFCCC secretariat · 22 April 2024

   “The report found that national climate action plans remain insufficient to limit the rise in global temperature to 1.5 °C and meet the goals of the Paris Agreement.”

4. E4 2018 Predictions: Calibration Results Slate Star Codex (Scott Alexander) · 22 January 2019 Own record

   “And while you're waiting, I also made some predictions last February for the next five years.”

E1 and E2 show the Paris Agreement had Parties in 2023 and that the latest NDCs covered 195 Parties. The evidence does not cover the reporting element the criteria require. E4 does not confirm that the February 2018 post gave this item an 80% probability, which the criteria require.