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I don't know. That 0.03C response was for a single year. I think it is at least consistent with the hypothesis that aerosols have a big impact and that at current levels they are likely masking a lot of the GHG warming potential. Imagine if that 0.03C rate of change persisted for 10 years. That'd be a cumulative 0.3C change. I'm not really endorsing aerosols as a means of geoengineering here though. The safest thing to do would be to minimize human influence altogether. That way we aren't trying to fight one influencing factor with yet another influencing factor.

We are starting to see studies regarding just how much the pandemic influenced the global mean temperature in 2020. https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020GL091805 About +0.03C per the study above and is attributable to reduced aerosol optical depths.

I believe it will be in March. https://www.emc.ncep.noaa.gov/users/meg/gfsv16/

Oh yeah. I totally remember. I did remove UAH and RSS from my model...just didn't add any skill no matter what weighting I gave it. In fact once I started adding other inputs UAH and RSS became more of a liability than an asset. Yes. I was running the GISTEMP code on the GHCN files. The land only index from GISTEMP actually added some skill to my model with 20% weighting. Getting the ERSST data plugged in proved very difficult at least for me. I just didn't have the time to spend on doing it. The input that mattered the most for me was Nick Stoke's TempLS dataset. I gave this input 50% weighting. When it was all said and done my model could predict the GISS update within 0.05 with 95% confidence. The guys posting as takeyourmoney and James Davis were clearly very smart. They had the modeling thing figured out long before I made my attempt. I wish those two would make an appearance on here. They were always respectful and their posts were packed full of relevant to the point information. They would be fun to engage with here.

That was me!

James Hansen says in his December update (just out today) that he thinks the warming may be accelerating as well. http://www.columbia.edu/~jeh1/mailings/2021/20210114_Temperature2020.pdf

Yes I did. It was pretty nuanced though. The rules said 2020 had to exceed 2016 by 0.01 after rounding to 2 decimal places. The quirk was that 2016 had been getting reported as 1.01. But I (along with several other people) had figured out that the recent addition of observations into the GHCN repository was going to likely flip 2016 back to 1.02. And my model had predicted that GISS would revise Nov down to 1.11 and report 0.83 for Dec. GISS officially reported 1.11 and 0.81 respectively so I had already seen the 2020 round down to 1.02 coming as well. I exploited that situation as well. In the end I learned a lot from this exercise. First...I learned that prediction markets aren't that good. Second...I learned a lot of details about GHCN, ERSST, how the GISTEMP code works, and how to create a model for predicting GISS updates with publicly available information with up to 4 weeks lead time. It was really fun. BTW...your comment above about 2010 being a good analog to 2020 kept me on my guard

Berkeley Earth released their 2020 annual report. 2020 was the second warmest year behind 2016. http://berkeleyearth.org/global-temperature-report-for-2020/

2020 has eclipsed 2016 as the warmest year in the GISS record strictly speaking. But it was of the thinnest of margins and qualifies as a statistical tie.

Dr. Spencer posted documents containing the official seal of the Office of Science and Technology Policy on his blog under the direction of David Legates. These documents represent the views of a whos who list of contrarian scientists. http://www.drroyspencer.com/2021/01/white-house-brochures-on-climate-there-is-no-climate-crisis/ These documents are disinformation at best. They certainly don't represent "the current state-of-the-science on various topics of climate change" as Legates claim. In addition the OSTP did not grant approval to disseminate these documents. It is not even clear they were aware of their existence until now. https://www.washingtonpost.com/weather/2021/01/11/controversial-climate-skeptics-release-papers/ Edit: Apparently the documents are also hosted by the Center for Environmental Research and Earth Sciences. https://www.ceres-science.com/content/climate_change_flyers.html Edit: David Legates and Ryan Maue have both been relieved of their duties in regards to the OSTP over this. https://www.washingtonpost.com/weather/2021/01/11/controversial-climate-skeptics-release-papers/ Edit: NOAA has issued a statement regarding the matter. https://www.noaa.gov/media-release/statement-on-climate-change-flyers-falsely-attributed-to-white-house-office-of-science https://arstechnica.com/science/2021/01/attempt-to-red-team-climate-research-comes-to-a-pathetic-and-confused-end/

Copernicus released their final monthly report for 2020. https://climate.copernicus.eu/surface-air-temperature-december-2020 2020 is the second warmest year in their record after 2016.

Per NSIDC the annual mean extent in 2020 was 10.160e6. This breaks the previous record of 10.163e6 set in 2016.

That was a good read. Full text here. There is some interesting commentary about how we've probably underestimated aerosol forcing. That's probably not a good thing since it means the warming may continue to accelerate as we clean up our aerosol emissions.

GISTEMP reported +1.13C for November easily beating out November 2015 for the #1 spot.

I got in at 35c a couple of weeks ago when my model was suggesting it should have been valued at 55c. My model is suggesting 80% odds now so there's not a lot of premium/discount to exploit anymore IMHO. I've found this to be a fun and challenging exercise. I've learned a lot in the last couple of weeks. I'm honing my statistical analysis skills (which are still subpar) and got the GISTEMP code running on my Ubuntu install. I also discovered that Nick Stokes' TempLS dataset which updates early makes a great predictor. He processes GHCN and ERSST directly.

I was hoping NASA would release the November GISTEMP update today. They didn't. My model is predicting the November value to come in at +1.10C +/- 0.11. At +1.10C December only needs to come in at +0.75C for the annual mean to hit +1.02C which would top 2016's value of +1.01C rounded the nearest hundredth. With observations + GFS forecast through December 15th my model is predicting a value of +0.99C and if this cooling rate persists through the second of half December as well that takes us down to around +0.93C for a final annual mean of +1.03C. We'll see what happens.

For a fun perspective on a crowed-sourced prediction regarding whether 2020 will beat out 2016 as the warmest year in the GISTEMP record check out this betting market.

ERA reported the warmest November on record by a wide margin. https://climate.copernicus.eu/surface-air-temperature-november-2020 IMHO this positions GISTEMP favorably to report the warmest year in their dataset. ERA couples reasonable well with GISTEMP.

NCAR reanalysis is running warm too. In fact as of the 18th it is warmer than both Oct and Sep. It could be a photo finish on whether 2020 beats out 2016 on the GISTEMP record even despite the ongoing La Nina.

I will say that GISTEMP came in at +0.90C for October which is 0.09C cooler than September. This lowers the odds of 2020 being the warmest. It's probably below 50% now.

HWRF, HMON, COAMPS, and experimental HAFS all have 98L attaining cat 4 intensity.

Hmm...maybe you're seeing something I'm not or perhaps your objection was regarding the method as opposed to the results but GISTEMP (which the Brown and Caldeira method is based) stands a reasonable chance of beating out 2016 still. We don't have the October value in yet but data from reanalysis leads me to believe that it could be elevated like the September value. And so far preliminary data for November is even warmer than October. Despite the La Nina I don't think we can confidently eliminate 2020 as being the warmest on the GISTEMP record yet. In fact, I'd say the odds are about 50/50 right now. Dr. Huasfather's analysis gives it an even higher 83% chance.

Yeah. It's something that is counter intuitive at first, but once you understand exactly how the GHE works and the fact that Antarctica has a unique vertical temperature profile it's pretty obvious it has to be this way. Unfortunately the negative GHE in this isolated region has its limits and will likely turn positive in the future here as well. Here is an interesting study that quantifies the effect. According to the authors most of the effect is actually attributed to water vapor which is a potent GHG itself. And it is the non-condensing GHGs (like CO2) that provide the secular nudge upward for water vapor concentration via the well known Clausius-Clapeyron lapse-rate feedback. https://www.nature.com/articles/s41612-018-0031-y Of course I don't mean to imply that the negative GHE is the sole or even dominant reason for the SH's weak polar amplification. Obviously many other factors are involved here with the most obvious being the larger percentage of ocean coverage relative to the NH.

Wow. Eta is definitely highlighting the problem with the CI number needing to be spooled in. ADTv9 has it clamped at 1.3T/6hr so it can't catch up with the raw value quickly enough.

A raw T# > 8.0 suggests a sub 900mb cyclone. I'll go 895 mb 150 kts.