Anyone make a hottest year market yet?

Temps look relatively flat and constrained for rest of the month

A +-0.2 offset range is probably too large, so anything within +- 0.1 range looks reasonable to me as a meta prediction... (anything between the green and pink lines as most likely at the moment):

This one time I computed for the Polymarket's bins as well to see how their spread compares to mine for reference and as usual it has a much tighter distribution. For reference polymarket is currently at 1.30-1.34 at 40% and >1.34 at 45%, suggesting something along the lines of the green or orange line; this implies an offset of about -0.1 C which is within range and I don't necessarily outright disagree with but I think a more flat 0.0C offset (purple line) is more likely given the forecast temps seem to mostly be flat rather than a trend rising or flat):

Edit (fixed graph):

Polymarket's percents for Jan. (diff bins from this question):

>@parhizj
Peak recent anomaly 1.33C for Oct and La Nina monthly values
2024 7 0.21
2024 8 -0.07
2024 9 -0.15
2024 10 -0.28
2024 11 -0.14
2024 12 -0.62
possibly starting to go down more steeply but maybe it is a while longer before that starts to have its effect?

ENSO cooling effect should be outweighing greenhouse gas slow steady effect?

I guess above sort of reasoning should carry little weight versus having data for January temps?

@ChristopherRandles I've been focusing on my own project and haven't had time to go through the comments on real climate, but I did read somewhere (news site?) that essentially climate scientists haven't reached a (detailed?) consensus on attribution for the extreme 2023-2024 anomalies:

https://www.realclimate.org/index.php/archives/2024/05/new-journal-nature-2023/

https://www.realclimate.org/index.php/archives/2024/12/nature-2023-part-ii/

The paper mentioned in the second post attributes most of it to change in albedo, between mostly northern mid-lat and tropics but still far away from filling in the details:

"What they can’t do using this methodology is partition the albedo changes across cloud feedbacks, aerosol effects, surface reflectivity, volcanic activity etc., and even less, partition that into the impacts of marine shipping emission reductions, Chinese aerosol emissions, aerosol-cloud interactions etc. So, in terms of what the ultimate cause(s) are, more work is still needed."

In the most recent post below though covering different baselines Gavin mentions something interesting regarding the anomalies though:

https://www.realclimate.org/index.php/archives/2025/01/2024-hindsight/

"With much of the focus on the longer-term records, it seems to have flown under the radar a little how oddly the MSU/AMSU records have been behaving over the last year or so. As with the surface records, the satellite products (UAH, RSS, NOAA STAR) all have 2024 and 2023 as the warmest and second warmest years, but unlike the surface records, 2023 was not such a outlier (~0.06ºC above 2016), while 2024 was huge (with records broken by ~0.32ºC). Additionally, the time over which the peak temperatures have lasted (17 months or so) is much shorter than the peaks around 2016 or 1998 (7 months). I don’t have much insight into why this is happening, but it might hold some clues about the drivers of the recent anomalies."

@ChristopherRandles

"ENSO cooling effect should be outweighing greenhouse gas slow steady effect?"

2020 tied for hottest year at the time, even tho it was the first year of the triple dip Nina.

@ScottSupak
Over 10+ years steady GHG effect tends to swamp other effects.
Over 1 year ENSO can swamp other effects, it is a short term effect.

For the 2020 year you picked a la Nina did develop but there were mild El Nino conditions at start of year. Being the first year makes it a little weaker of an effect than following two years when La Nina existed throughout the year.

2020 was also first year of 70% sulfur emissions reductions on marine fuel. Also a rapid effect so perhaps biggest warming effect in any one year from this.

So on an annual basis, while ENSO can swamps other effects, it does not always do so if the ENSO effects are weak/only part of year and/or a few other effects from GHG, marine fuel emissions, solar ... can combine to outweigh ENSO.

If instead we look on a monthly basis we can see than by Dec 2020 when La Nina had had a chance to kick in, the temperature was lower than each of the previous 5 Decembers.

@ChristopherRandles yes, of course, and so the question is how strong will this Nina be, and how strong will effects that can counter it be?

It’s very likely this La Niña will be weak, with the Niño-3.4 index unlikely to reach -1.0 °C for a season. This is based on computer model guidance and how late in the year La Niña conditions emerged. ENSO events peak in the northern Hemisphere winter, and there’s just not a lot of time for La Niña to strengthen.

@ScottSupak yes, so what do we see:
GHG steady as normal
Marine fuel still warming but by reducing amounts
Solar probably still marginally increasing warming effect
Hunga Tonga both warming and cooling effects now reversing back towards trend but probably by reducing amounts.

Basically unlike the 2020 situation there isn't a whole lot of significant new warming effects for January 2025 to counter Nina effects.

NINO3.4 anomaly dropped to -0.62 in Dec from -.014 for Nov (for latest data I am looking at monthly data rather than 3 month averages)
https://www.cpc.ncep.noaa.gov/data/indices/sstoi.indices
that is quite a sharp decline (certainly compared to recent 3 month averages drifting slowly lower) but I would point out there is also some uncertainty in timing in when this flows through to global average temperature. It might well be too soon to expect a strong effect from this in January.

Using monthly ENSO data rather than 3 month averages is probably a bit dodgy, longer period averages work better - which is probably admitting there is unpredictable residual noise. On monthly change in temp, this unpredictable residual noise might swamp the expected difference between ENSO and other known effects. Hence we could get a temperature increase despite an expectation for Nina cooling to outweigh GHG, solar and other known effects. For estimating January temp data, January temp data is probably more reliable than estimating what changes we expect from Dec.

That is perhaps just a more detailed explanation of why I wrote "I guess above sort of reasoning should carry little weight versus having data for January temps?"