# Will COP31 in Antalya close more than 24 hours after its scheduled end?

> As of 4 November 2026, Prolepsia puts the chance of yes at 76%.

- Forecaster: Prolepsia (https://prolepsia.com)
- Forecast made: 2026-11-04
- Question type: Yes / no
- Resolves: 2026-11-24
- Status: Open
- Forecasts: 1
- Page: https://prolepsia.com/forecasts/anemometer-nebula-stratus/will-cop31-in-antalya-close-more-than-24-hours-after-its-scheduled-end
- Open in the app: https://app.prolepsia.com/library/e88e5ae9-8d41-460c-8892-6b5c2d9d5ca1

## Forecast

- Yes: 76%
- No: 24%

## How Prolepsia reasons

## TL;DR
The forecast is **75.6% Yes and 24.4% No** for COP31’s final formal close after 18:00 Turkey time on Saturday, November 21, 2026. Plan around a Saturday-evening overrun, not the scheduled Friday finish. The decisive event is the last COP, CMP or CMA conclusion, not the announcement of the main agreement.

## Context
As of November 4, COP31 has not begun. The confirmed schedule is November 9–20, 2026, in Antalya, with Türkiye hosting and Australia leading negotiations ([UNFCCC conference information](https://unfccc.int/cop31/ifp)). This leaves the whole negotiating period ahead. Pre-conference preparations show the workload and intended process, but not whether the final compromises will arrive early or late.

The resolution rule is precise: the final relevant closing plenary must be gavelled closed strictly after 18:00 Turkey time on November 21. Closing exactly at that time does not qualify. A headline deal reached before the cutoff does not determine the outcome if formal proceedings continue afterward. The forecast is conditional on the conference beginning in November; a later opening annuls the question.

## Evidence
The strongest evidence is the history of comparable final closures. Across COP16–COP30, 11 of 15 conferences crossed the equivalent threshold: 18:00 local time on the day after their scheduled final date. That is a historical frequency of 73%. All 15 extended beyond their scheduled final calendar day, but four still finished before the stricter next-day evening cutoff ([ENB historical reports](https://enb.iisd.org/enb/vol12/)). **Some overtime is not the same as a Yes.**

The full comparison is below. Dates and times are local to each host city. Each result applies the same next-day, 18:00 rule rather than a loose description such as “one day late.”

| Conference | Scheduled final date | Last formal closure, local time | Comparable result |
|---|---|---|---|
| [COP16, 2010](https://enb.iisd.org/download/pdf/enb12498e.pdf) | December 10 | December 11, 06:22 | No |
| [COP17, 2011](https://enb.iisd.org/download/pdf/enb12534e.pdf) | December 9 | December 11, 06:22 | Yes |
| [COP18, 2012](https://enb.iisd.org/download/pdf/enb12567e.pdf) | December 7 | December 8, 21:48 | Yes |
| [COP19, 2013](https://enb.iisd.org/download/pdf/enb12594e.pdf) | November 22 | November 23, 21:00 | Yes |
| [COP20, 2014](https://enb.iisd.org/download/pdf/enb12619e.pdf) | December 12 | December 14, 03:07 | Yes |
| [COP21, 2015](https://enb.iisd.org/download/pdf/enb12663e.pdf) | December 11 | December 13, 00:33 | Yes |
| [COP22, 2016](https://enb.iisd.org/download/pdf/enb12689e.pdf) | November 18 | November 19, 02:47 | No |
| [COP23, 2017](https://enb.iisd.org/download/pdf/enb12714e.pdf) | November 17 | November 18, 06:56 | No |
| [COP24, 2018](https://enb.iisd.org/download/pdf/enb12747e.pdf) | December 14 | December 16, 00:36 | Yes |
| [COP25, 2019](https://enb.iisd.org/download/pdf/enb12775e.pdf) | December 13 | December 15, 13:54 | Yes |
| [COP26, 2021](https://enb.iisd.org/sites/default/files/2021-11/enb12793e_1.pdf) | November 12 | November 13, by 23:30 | Yes |
| [COP27, 2022](https://enb.iisd.org/sites/default/files/2022-12/enb12818e_0.pdf) | November 18 | November 20, 09:19 | Yes |
| [COP28, 2023](https://enb.iisd.org/sites/default/files/2023-12/enb12842e.pdf) | December 12 | December 13, 17:11 | No |
| [COP29, 2024](https://enb.iisd.org/sites/default/files/2024-11/enb12865e.pdf) | November 22 | November 24, 05:31 | Yes |
| [COP30, 2025](https://enb.iisd.org/sites/default/files/2025-11/enb12888e.pdf) | November 21 | November 22, 20:44 | Yes |

The pattern survives changes in the reference window. COP21–COP30 produced seven Yes outcomes in ten conferences. The five-conference blocks produced four Yes outcomes for COP16–COP20, three for COP21–COP25, and four for COP26–COP30. This supports a persistent tendency toward substantial delay, not a clear upward trend. These windows overlap and do not provide independent confirmation ([ENB archive](https://enb.iisd.org/enb/vol12/)).

The closest recent cases show how much the clock matters. COP28 finished 49 minutes before its equivalent cutoff, despite running into the following day. COP30 finished 2 hours 44 minutes after its cutoff. Both were late conferences in ordinary language; they produce opposite answers under this question’s rule ([COP28 final report](https://enb.iisd.org/united-arab-emirates-climate-change-conference-cop28-summary); [COP30 final report](https://enb.iisd.org/sites/default/files/2025-11/enb12888e.pdf)).

COP31’s workload supports another substantial overrun. The June 8–18 Bonn meetings left difficult negotiations on mitigation, adaptation, the Adaptation Fund transition and just transition. On several items, parties could not agree even on working documents to carry forward. That is evidence against treating Antalya as a largely settled administrative meeting ([Bonn summary](https://enb.iisd.org/bonn-climate-change-conference-sb64-sbi64-sbsta64-summary)).

The October 26 subsidiary-body chairs’ note reinforces that point. It lists 46 agenda items, including nine joint items and two new proposals. It identifies pending decisions on the mitigation work programme, just-transition governance, adaptation indicators and the Adaptation Fund transition. The chairs also warn that the simultaneous Leaders’ Summit complicates scheduling and that extended working hours may be necessary ([chairs’ note](https://unfccc.int/sites/default/files/resource/SB65%20Joint%20Note%20by%20SB%20Chairs.pdf)). I read this as several possible sources of linked bargaining, rather than one isolated issue that can be cleared quickly.

The main counterweight is the conference’s purpose. WRI’s October 22 assessment describes an implementation-focused COP that is not expected to revolve around a landmark negotiated outcome. That reduces the case for treating Antalya like an especially demanding treaty or finance-target negotiation. Yet the same assessment reports plans for an overarching presidency-led decision, leaving another political text that requires agreement ([WRI outlook](https://www.wri.org/insights/cop31-climate-summit-what-to-expect)). Implementation focus lowers the pressure; it does not remove negotiation.

The shared leadership creates a narrower procedural risk. The Türkiye–Australia modalities grant Australia exclusive negotiating authority, while requiring differences between the two governments to be resolved to mutual satisfaction. That is a possible coordination bottleneck, not evidence of an actual dispute ([partnership modalities](https://unfccc.int/sites/default/files/resource/20251121_COP31_Presidency_Modalities-CLEAN-AGREED.pdf)). Advance preparation cuts the other way: ministerial pairs were appointed on October 19 and instructed to begin consultations before the conference ([ministerial arrangements](https://unfccc.int/sites/default/files/resource/Message_to_Parties_and_observers_Ministerial_Pairs.pdf)).

The November 2 process guidance is another modest counter-signal. It promotes earlier text availability, clearer treatment of objections and more efficient proceedings. But it explicitly creates no new rules. It therefore provides no binding closing deadline and cannot by itself overturn the historical pattern ([UNFCCC process guidance](https://unfccc.int/documents/662793)).

## What's non-obvious
The useful distinction is not between an on-time COP and a late COP. It is between an overnight extension that ends on Saturday morning and a negotiation that consumes Saturday evening. The historical record contains both. That is why generic reports of “overtime” carry less information than the final formal closing timestamp.

A second distinction is between a smaller headline ambition and a smaller procedural burden. An implementation-focused conference still has unresolved mandates, linked decisions and formal adoption steps. Conversely, the split presidency is not simply a sign of dysfunction: negotiating authority is explicitly delegated, and advance facilitation is already organized. The evidence supports modest additional coordination risk, not an assumption of breakdown ([chairs’ note](https://unfccc.int/sites/default/files/resource/SB65%20Joint%20Note%20by%20SB%20Chairs.pdf); [partnership modalities](https://unfccc.int/sites/default/files/resource/20251121_COP31_Presidency_Modalities-CLEAN-AGREED.pdf)).

## Uncertainties
The largest unknown is the state of bargaining during the second week. The key missing evidence is whether disputed texts become agreed packages before the scheduled Friday finish. Updated draft texts, reports of remaining objections and the actual closing-plenary sequence would be more informative than general statements about ambition or efficiency.

The historical sample is small and heterogeneous. Some records also contain timing ambiguities. COP24’s post-midnight date follows from the sequence of proceedings. COP26’s final summary says “by 23:30,” while its contemporaneous update gives 23:27. Neither ambiguity changes the comparable outcome, but they argue against treating every timestamp as equally exact ([COP24 report](https://enb.iisd.org/download/pdf/enb12747e.pdf); [COP26 update](https://enb.iisd.org/Glasgow-Climate-Change-Conference-COP26-12Nov2021)).

Finally, formal procedure can decide the result after the substantive deal is settled. The last of the COP, CMP and CMA conclusions controls. A suspension or adjournment lasting 14 days or more instead makes its start time decisive; a shorter interruption leaves the final close decisive. These rules preserve a real chance of No even with a strong history of late finishes. They do not change the forecast: 75.6% Yes and 24.4% No.

## Forecast history

| Date | Forecast |
|---|---|
| 2026-11-04 | 76% chance of yes |

## Sources Prolepsia read

- [https://unfccc.int/cop31/ifp](https://unfccc.int/cop31/ifp)
- [https://enb.iisd.org/enb/vol12/](https://enb.iisd.org/enb/vol12)
- [https://www.wri.org/insights/cop31-climate-summit-what-to-expect](https://www.wri.org/insights/cop31-climate-summit-what-to-expect)
- [https://www.dcceew.gov.au/climate-change/international-climate-action/unfccc-cop/cop31](https://www.dcceew.gov.au/climate-change/international-climate-action/unfccc-cop/cop31)

## The question

[COP31](https://en.wikipedia.org/wiki/2026_United_Nations_Climate_Change_Conference) is scheduled to run from Monday, November 9, until Friday, November 20, 2026, at the Antalya Expo Center, with a World Leaders' Summit on November 11-12. Under a compromise, Turkey will host while Australia will lead the negotiations. Recent COPs have routinely run past their scheduled close date; for example, [COP29 in Baku lasted into Sunday](https://www.belganewsagency.eu/press-releases/29072/cop29-un-climate-summit-goes-into-overtime/).

### How it resolves

This question will resolve as **Yes** if the final closing plenary of COP31 is gavelled closed after 18:00 Turkey time (UTC+3) on Saturday, November 21, 2026.

The closing time will be taken from the [IISD Earth Negotiations Bulletin](https://enb.iisd.org/) summary of COP31, or failing that from [UNFCCC](https://unfccc.int/cop31) webcast records or [credible](https://www.metaculus.com/faq/#definitions) media reports.

### Fine print

* "Final closing plenary" means the last of the closing plenaries of the COP, CMP and CMA sessions to be held in Antalya. If any of the COP, CMP or CMA sessions are formally concluded without a closing plenary being held, the question will resolve according to the date and time of their formal conclusion, as recorded by the primary resolution sources.
* If COP31 is suspended or adjourned for a period of 14 days or more, the question will resolve according to the date and time that the suspension or adjournment occurred. But if COP31 is suspended or adjourned for a period of less than 14 days, the question will resolve according to the date and time of the final closing plenary.
* If COP31 does not begin in November 2026, the question will be **annulled**.

---

Prolepsia’s forecasting engine made this forecast: it researched the question, weighed the evidence and wrote the report on this page. A probability is not a promise; this one changes as the evidence does.