Global average surface temperature anomalies remain above 1.5°C through 2029.
Evaluates near-term persistence of warming thresholds. Resolves as true if annual mean global temperatures tracked by major agencies remain at least 1.5°C above pre-industrial levels through 2029.
Across 6 frontier models answering independently, the panel leans no: the median is 48%.
They do not agree: Qwen puts it at 72% and DeepSeek at 8%, 64 points apart. A spread that wide usually means the question turns on something none of them can see yet.
Nothing is settled until 9 Oct 2029, when the outcome is checked against sources and every number above gets a permanent score.
What each one said
-
QwenAlibaba
El Niño–driven 2024 spike made 1.5°C look routine, but La Niña cooling in 2025–26 could dip a year below.
- 2023 and 2024 both exceeded 1.5°C (Copernicus/WMO); the underlying trend is ~0.2°C/decade, so the baseline is now ~1.3–1.35°C.
- A moderate-to-strong La Niña developing in 2025–26 could pull one annual mean to ~1.4°C, as 2021–22 hovered near 1.1–1.2°C during La Niña.
- If any single year 2025–2029 falls below 1.5°C the statement fails; the most likely candidate is a La Niña year, but the trend is rising fast enough that even cool years…
72% -
GrokxAI
Whether ENSO-driven cooling can push any 2026-29 annual GMST below 1.5 °C against a rising forced trend.
- NASA/NOAA/HadCRUT/Copernicus 2024 means already sit at 1.48-1.60 °C; the 0.20 °C/decade forced rise lifts the 2026-29 expected mean to ~1.58 °C.
- Internal variability (ENSO) has ~0.10 °C annual SD, so a strong La Niña still has ~25 % chance of dipping one year below 1.5; four years raise the joint risk to ~38 %.
- A 2027-28 Super El Niño or faster aerosol-cleanup warming would push the probability above 75 %; a multi-year La Niña cluster would drop it below 40 %.
62% -
GPTOpenAI
The outcome hinges on whether La Niña years and aerosol/volcanic variability can pull any annual mean below 1.5°C before 2029.
- WMO/Copernicus put 2024 near 1.55°C above 1850–1900, but a single-record year is not yet a durable annual threshold.
- Agencies must report every full calendar year from 2026–2029 at or above the cutoff; ENSO commonly shifts global means by roughly 0.1–0.2°C.
- Odds rise sharply if 2026 stays above 1.5°C despite La Niña conditions; a sustained strong La Niña or major eruption would reverse the case.
58% -
GeminiGoogle
Unbroken >=1.5C years through 2029 require background warming to outpace expected cooling from multi-year post-El Nino La Nina phases.
- While 2023-2024 breached 1.5C, historical ENSO variability typically pulls anomalies down by 0.1C to 0.2C during neutral or La Nina years.
- WMO models estimate an 80% chance of at least one year exceeding 1.5C by 2028, but only a 47% chance the five-year mean exceeds it.
- A prolonged multi-year La Nina before 2029 will almost certainly dip an annual anomaly to ~1.4C, breaking the unbroken streak.
38% -
ClaudeAnthropic
Depends on whether La Niña cooling and natural variability pull annual means briefly below 1.5°C despite the warming trend.
- 2023-2025 saw repeated years at or above 1.5°C but with ENSO-driven dips, and a strong La Niña could push an annual mean back to 1.3-1.4°C.
- 'Remain above' through all years to 2029 is a stricter bar than hitting 1.5°C once; natural variability makes multi-year persistence above threshold less likely than…
- If a major La Niña event in 2026-2028 drops global mean temperature anomaly noticeably, that single year breaks the 'remain above' condition and resolves false.
22% -
DeepSeekDeepSeek
Three consecutive years above 1.5°C is unprecedented; ENSO cooling makes a multi-year streak unlikely.
- Only 2024 (1.55°C) and possibly 2025 have exceeded 1.5°C annually; WMO data show 2023 was 1.45°C, so the base rate for any single year above 1.5°C is under 20%.
- La Niña conditions in 2025-2026 will likely cool 2026-2027 below 1.5°C, as ENSO shifts redistribute heat and break the streak before 2029.
- A sustained major volcanic eruption or unexpected acceleration in aerosol reduction would be needed to keep all four years above threshold, which is historically…
8%
6 of 6 models answered · 64 points between the highest and lowest. None was shown the market price.
Question sourced from a news sweep on 10 Oct 2026. Forecast by google/gemini-3.8-flash, anthropic/claude-sonnet-5, openai/gpt-5.6-terra, x-ai/grok-4.6, deepseek/deepseek-v4.1-flash, qwen/qwen3.8-max-0902 via OpenRouter.