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ENSO does not create long term planetary scale energy imbalances. It just moves heat around. ONI has averaged 0.1 from 1979 to present with a trend of -0.028/decade +- 0.031. The AMOC, on the other hand, probably does play a big role. But scientists already consider its role. It helps explain the magnitude of the MWP and LIA in the North Atlantic during the holocene for example. It has also been invoked to help explain the last deglaciation (see Shakun 2012). It is believed the AMOC will play a critical role in the contemporary warming period in the not so distant future as well. The point...there are many agents that help drive the climate. They are all important and should be considered. That in no way takes away from the fact that CO2 (and other GHGs) plays a crucial role as well. We just happen to be living in an era where CO2, CH4, CFCs, O3, and other GHGs have dominated the positive side of the radiative forcing budget by about an order of magnitude.

That's right. Water so greedily absorbs IR radiation that it is completely absorbed in the skin layer. It is an effect that is exploited by IR lamps to keep our food warmer for longer than it would be otherwise in restaurants. I think this publication has been misinterpreted. This publication does NOT claim or even imply that IR radiation does not warm the ocean. It is quite the opposite actually. What it does do is present a hypothesis for the exact mechanism by which increased downwelling IR radiation causes the oceans to warm. In a nutshell the hypothesis is that a temperature gradient in the skin is reduced thus reducing the conductivity of heat from the subsurface to the ocean-air interface. Read what they conclude. and This publication is all-in that an increase in downwelling IR is consistent with broad depth oceanic heat content increases. and IR radiation is a mechanism by which the depths of the ocean warm. The paper even provides us with a microphysical mechanism by which the heat is "trapped" below the skin layer.

Yep. I'm well aware of that publication. It is authored by Dr. Christy and Dr. Spencer. First...they are the maintainers of the UAH satellite dataset so this is not an independent assessment. Second...they use the IGRA radiosonde dataset for the assessment. This dataset is NOT to be used for climate research. Let me just post the text as it appears exactly on the IGRA website. https://www.ncdc.noaa.gov/data-access/weather-balloon/integrated-global-radiosonde-archive Third...notice what they've done in that graphic. This is not a global assessment of differences. It is a narrowly focused assessment centered on the tropical region in the mid troposphere. And only up to 2005 even though the paper was published in 2018. Fourth...look at the UW entry on the graph. That is the University of Washington which attempts to remove the stratospheric cooling contamination from both RSS and UAH. They come to a different conclusion than what this paper is advertising.

You've missed a crucial point. Moving heat around does not change how much heat the Earth is accumulating. It just moves it around. Heat accumulation/uptake is an instantaneous concept. It is not lagged in any significant way (with a caveat we can discuss later). Changes in solar radiation have an instant and immediately effect on Earth Energy Imbalance (EEI). What is lagged are the individual responses that arise from that trapped heat. Atmospheric temperature is a lagged response due mostly to the thermal inertia of the oceans. When you turn down the burner on a stove with a pot of water the water may continue to warm. But it will warm at a SLOWER rate if it continues to warm at all. Likewise, if you turn down the Sun the heat uptake of Earth will slow down if Earth continues to accumulate heat at all. All other things being equal of course. But what we observe is that both the total heat uptake and the atmospheric temperature have accelerated while EEI remains persistently high despite this warming since the Sun entered a more quiescent state. Energy trapping is instant. Atmospheric temperature response is what is lagged. The solar hypothesis is not being challenged from atmospheric temperature measurements alone. It is being challenged from total heat uptake, EEI measurements among other lines of evidence.

Sure. But... What we observe is an acceleration of the heat uptake and warming rates and roughly at about the same time the Sun began a more quiescent period. At the very least a quieter Sun would result in a reduction of the trapping of energy.

Let's be precise. The 2σ error on a 5yr centered mean 150 years ago is about 0.100C. 100 years ago it is about 0.085C. 60 years ago it is about 0.035C. Obviously everyone agrees that 0.1C error is larger than 0.035C of error. But I don't think many people are going to consider these measurements to be BS because of it. Source. Then it should have been easy to identify. Of course, you'd still have the problem of figuring out where all of that accumulated (aka "trapped") energy that GHGs yielded went if not into warming the atmosphere and hydrosphere. This is tough nut to crack for sure. Yes and no. First...that's no different than using Kepler's model of planetary motion or Einsteins model of general relatively to "prove" that the Sun is the primary component of Earth's movement in the solar system for example. I mean science constructs models specifically to address to question like these. It's ubiquitous across all disciplines of science so I don't see what the problem is here. Second...there are many observational lines of evidence that corroborate CO2's role while simultaneously eliminating other candidates (like the cooling stratosphere simultaneous with the warming troposphere and hydrosphere). And the various models like radiative transfer schems, energy balance, and GCMs are developed from observational evidence themselves. So if the implication is that "model" means "no observations" then that's not giving the state of the science a fair shake. Science constructs models that approximate reality. That's kind of the point of science actually. And when more than one model exists scientists, engineers, or other decision makers typically choose the one that provides the best match to reality with no more complexity than is absolutely necessary for the task. Ah...when you say model you actually mean "global circulation model". Not all climate models are GCMs, but GCMs are a type of climate model. The most primitive climate model came in the late 1800's (see Arrhenius 1896). Models got more sophisticated and by the 1950's were using radiative transfer schemes (see Plass 1956). By the 70's climate models achieved a level of sophistication requiring numerical weather prediction techniques via global circulation models. By the 1980's these GCMs were incorporating many GHG species, solar effects, aerosol effects, etc. (see Hansen 1988). Radiative transfer schemes themselves were improving as well (see Myhre 1998). We also have energy balance models (see Wild 2013). More to the point...in the GCM arena even the primitive ones from 30 years ago ended up performing reasonably well (see Hausfather 2020). So while they may be considered crude they still work well and are orders of magnitude more complex than their non-GCM counterparts appearing between 60-120 years ago. All models have problems. That's why they are only approximations of reality. It's a good thing scientists do not base their conclusions on future warming from GCMs alone. As expected. CO2 is both in a forcing AND a feedback relationship with the temperature. When something else catalyzes the temperature change CO2 acts via its feedback first and then as a forcing agent second to amplify the temperature change. When CO2 itself catalyzes the temperature change it acts as a forcing agent first and then via its feedback it will amplify the change through the perturbation of existing source/sink fluxes. It would be rather odd if we had discovered that CO2 lead the temperature changes during the glacial cycles. But there are other events in the paleoclimate record in which CO2 did lead the temperature. These include the hyperthermal events. The most notable of which and the one that is most analogous to the contemporary warning is the PETM. There was a sudden and dramatic release of carbon (possibly CH4 or CO2 or both) that preceded the hyperthermal just like the other ETMx events. Because it is a radiative forcing agent and because it is being released during an era in which other modulating factors have remained relatively unchanged or may have actually caused a cooling tendency. It has happened. Many times in fact. I would consider the glacial cycles of the Quaternary Period a flip from one extreme to another. But of course their have been snowball Earth and hothouse Earth conditions as well. But remember...H2O is a condensing gas. CO2 is non-condensing. H2O produces a radiative forcing but due to its condensing nature it is not considered a forcing agent since it cannot, on its own, catalyze a long term change in temperature. It is happy to remain in its stable equilibrium with the temperature via the Clausius-Clapeyron relationship all other things remaining equal. In other words, H2O can amplify an already catalyzed change, but it cannot actually catalyze that change on its own. Ocean currents are important. But not in terms in of Earth's Energy Imbalance (EEI). Ocean currents do not create energy or directly change EEI. Their contribution to the EEI is thus 0 W/m^2. CO2's contribution from 280 to 410 ppm is +2.0 W/m^2. That makes CO2 vastly more important to Earth's secular climate trends than ocean currents which only have a cyclic effect through their ebb and flow of heat transfer fluxes to/from the atmosphere and deep ocean and how this heat is distribution over the Earth. Yes it does. Quite literally in fact. In the context in which it is used in climate science the word "trap" means energy (and by extension heat) is accumulating via a planetary scale energy imbalance. This imbalance is currently +0.6 W/m^2. Therefore 0.6 W/m^2 is being "trapped" in the geosphere. CO2's un-equilibriated radiative force is a significant contributor to this "trapped" energy. The Sun is not THE control knob, but only A control knob. There are other factors that modulate the climate. It is the net effect of all of them matters. Sometimes the Sun does dominate. Sometimes volcanoes dominate. Sometimes orbital cycles provide the nudge to hit the tipping point. We just happen to be living in an era when GHGs are dominating. BTW...it's really easy to falsify the "It's the Sun stupid" hypothesis. First...like all main sequence stars the Sun brightens and warms with age. The rate is about 1% every 120 million years see (Gough 1981). The paleoclimate record shows secular cooling over million year time scales despite solar luminosity increasing. If the Sun where THE control knob then we should have expected the Earth to warm. But that didn't happen. This is the crux of the faint young paradox. Why was Earth so warm in the distant past when the Sun was significantly less bright? Second...over the contemporary warming period and especially since 1960 solar radiation has been mostly flat and has even started to decline in the most recent decades. Yet the warming rate didn't turn negative. In fact, the warming actually accelerated during this period and in complete opposition to total solar irradiance (see SORCE). This leaves only solar magnetic flux as a candidate for influence. But as I've pointed in other posts there are far too many problems with the galactic cosmic ray hypothesis to consider it a viable hypothesis at this point. I can provide references if necessary.

Hmm...I'm not sure what you mean by "artificially inflate". Here is RSS's paper describing their changes in v4. https://journals.ametsoc.org/jcli/article/30/19/7695/342699/A-Satellite-Derived-Lower-Tropospheric-Atmospheric RSS matches other observational sources including but not limited to. STAR: https://www.ncdc.noaa.gov/temp-and-precip/msu/global/mt/dec/ytd RATPAC: https://www.ncdc.noaa.gov/sotc/upper-air/201913 ERA: https://climate.copernicus.eu/sites/default/files/2020-08/ts_1month_anomaly_Global_ERA5_2T_202007_v01.csv Berkeley Earth: http://berkeleyearth.lbl.gov/auto/Global/Land_and_Ocean_complete.txt GISTEMP: https://data.giss.nasa.gov/gistemp/graphs_v4/graph_data/Monthly_Mean_Global_Surface_Temperature/graph.txt Cowtan & Way: https://www-users.york.ac.uk/~kdc3/papers/coverage2013/series.html JMA: https://ds.data.jma.go.jp/tcc/tcc/products/gwp/temp/ann_wld.html HadCRUT: https://crudata.uea.ac.uk/cru/data/temperature/ NOAA Global Temp: https://www.ncei.noaa.gov/data/noaa-global-surface-temperature/v5/access/timeseries/aravg.ann.land_ocean.90S.90N.v5.0.0.202007.asc All datasets are adjusted. That is a good thing. We want dataset developers and maintainers to make adjustments to correct for mistakes, biases, data quality issues, non-climatic effects, etc. That does not mean these datasets are fundamentally flawed. adjusted != flawed and adjusted == good And remember UAH makes all kinds of adjustments too. They don't even directly measure the temperature. They have to derive it using a complex model that maps microwave emissions from O2 molecules into a meaningful temperature. And they have to make adjustments to correct for things like orbital decay, diurnal drift, and instrument body effect. Then they have to homogenize the data to provide global coverage while dealing with subtle nuances in the polar regions. No source code is provided by UAH. Not that I think this is a problem. Many datasets decline to publish the details of their techniques. However many datasets like GISTEMP openly publish their source code for all to review. Out of the more than a dozen datasets in existence that publish a global mean temperature UAH is the outlier; perhaps even a lone outlier compared against the backdrop of the more well known GMST datasets. Many are suspicious that the UAH TLT product is being contaminated by the cooling stratosphere. RSS TLT != UAH TLT. RSS weights their TLT product much lower than UAH's TLT product. And from their TMT products it is RSS that has a better match to balloon observations. https://www.ncdc.noaa.gov/sotc/upper-air/201913 There are also data merging issues. https://journals.ametsoc.org/jtech/article/34/1/225/342433/A-Comparative-Analysis-of-Data-Derived-from Please review the published data linked to above concerning the global mean temperature. Scientists do have an idea. The uncertainty envelope is definitely wider in the past. But it is not infinitely wide. For example Berkeley Earth lists less than 0.10C for the annual mean error from 1880 onward. This is reduced to less than 0.07C error if using the 5 year centered running mean. Annual mean errors drop to 0.05C after 1960. The science says climate change IS a component. Even with non-climatic changes controlled for the Phoenix area trend is clearly upwards. It's hard to say how much of Phoenix's warming is due to the broad increase in the global mean temperature or more cyclic climate phenomenon like the PDO, AMO, etc. But we know from first principal reasoning that climate change HAS to be factor because temperature trends are a product of ALL modulating effects. https://data.giss.nasa.gov/cgi-bin/gistemp/stdata_show_v4.cgi?id=USW00093140&ds=14&dt=1 https://data.giss.nasa.gov/cgi-bin/gistemp/stdata_show_v4.cgi?id=USW00023183&ds=14&dt=1

The NSIDC extent change was -196k yesterday. The daily extent as of 9/1 is 4.004e6 km^2 and easily locks 2020 into 2nd place for the daily summer minimum.

There was a pretty sharp loss the last 2 days. This brings the daily extent below 2019 as of 8/20 per NSIDC. The 5-day average is still in 3rd place for this date.

Probably. Yes. There is an incredibly detailed and lengthy write up by William Reid and Christopher Burt regarding the matter. The investigation is still on-going, but unless something has changed it is my understanding that this will eventually be presented to the WMO for official review. The following is a lengthy 8-part series summarizing the state of the investigation through March 2020 from William Reid. http://stormbruiser.com/chase/2013/08/29/death-valleys-134f-record-temperature-study-part-one/ You can review a considerably more consolidated summary on Christopher Burt's blog. https://www.wunderground.com/blog/weatherhistorian/an-investigation-of-death-valleys-134f-world-temperature-record.html

Unfortunately I cannot find a copy of this newly published study that isn't behind a paywall. But it is said that it supports a 2035 target for the first ice-free summer according to news articles. https://www.nature.com/articles/s41558-020-0865-2

Hmm...maybe this is my misunderstanding but I was under the impression that sea ice would tend to cling to the northern coast of Greenland for decades to come and possibly through the remainder of this century even during the summer. But after seeing the substantial reductions in this area in 2020 I'm now obviously questioning that assumption. I was also an advocate of more moderate estimates of the first "ice-free" summer tending to favor 2050 or so. Again...I'm starting to question my position in this regard as well.

Gotcha. Thanks. That's helpful. I try to lurk as much as I can on the Arctic Sea Ice Forum. Sea ice is such a complicated beast to understand.

I'm still trying to learn the ins and outs of Arctic sea ice. I've gotten a pretty good understanding of some of the things that negatively affect the ice. What was the pattern like in July and August of 2012?

ERA 2mT reanalysis is +0.627 for May. This is the warmest May on record. https://climate.copernicus.eu/surface-air-temperature-may-2020

NCEP/NCAR 2mT reanalysis was -0.08C from April to May. UAH's TLT product doesn't always move in tandem with the surface temperature. In fact, it often moves in the opposite direction. BTW...I just recently learned that UAH's TLT product is actually derived from their MT, TP, and LS products. Specifically the weighting is LT = 1.538*MT + -0.548*TP + 0.01*LS. I've mentioned this before, but I wonder how much the stratospheric cooling is contaminating their TLT product. https://www.drroyspencer.com/wp-content/uploads/APJAS-2016-UAH-Version-6-Global-Satellite-Temperature-Products-for-blog-post.pdf

Here is an update of the CMIP5 vs observation comparison as of March/2020. CarbonBrief

That's what the GISS group wanted to do. Other groups use different baselines. All it does is to make a baseline from which the anomalies are computed. You can pick any baseline you want. It can be an entirely arbitrary decision. It does not change the ranking of the years, the warming trend, or the structure of the graph chubbs posted.

That April 2020 update from UAH brings their trend up one notch to +0.14C/decade now. For comparison Berkeley Earth is +0.19C/decade, RSS is +0.21C/decade, and ERA is +0.19C/decade over the same time period.

UAH also recorded another increase in stratospheric temperatures. If history is any guide then that means further troposphere cooling is around the corner. The leading hypothesis for stratospheric warming is still wildfire smoke.

Another day and another sharp decline. The NSIDC did call the top as March 5th.

March 5 with a 5d average of 15.047 on NSIDC might be the max. I'd give greater than 50% odds at this point. We'll see.

RSS was up in February, but not as much. ERA was only up by 0.02C. I keep wondering if UAH is contaminated by what happens in the stratosphere more so than RSS. If so that would partly explain UAH's 0.13C/decade trend which is far lower than what any other dataset shows.

Maybe. I was watching aerosol optical depths closely after that eruption and while there was a lot tephra lofted into the troposphere it didn't appear as if much sulphate aerosols made it into the stratosphere. I think the Australia wildfire smoke is a better hypothesis at this point. In regards to the troposphere...volcanoes typically cool this layer. I don't know of a case where warming resulted from an eruption. And I'm not understanding the link with smoke either. I thought smoke was more effective at blocking incoming shortwave radiation than it was at trapping outgoing longwave radiation.

Hmm...Dr. Spencer is suggesting the smoke warmed both the troposphere and stratosphere. Typically aerosols cool the troposhere and warm the stratosphere. This is an unusual event in that the spike up is observed in both layers. I'm a bit skeptical of his smoke causing radiation induced warming (aka greenhouse effect) claim, but I'm open to hearing what evidence he presents. The thing is that the February troposphere anomaly is primarily the result of warming in the NH. My first thought is that the record +AO may be partly to blame with the spike.