JCH, is this nonsense too?
https://www.nature.com/articles/s41612-018-0044-6
AGW will end up being nonsense.
Comment on Week in review – science edition by edimbukvarevic
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Comment on Week in review – science edition by JCH
Yes, it’s nonsense. The equivalent of reading tea leaves.
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Comment on Week in review – science edition by JCH
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Comment on Climate sensitivity to cumulative carbon emissions by Robert I. Ellison
It is not ignored – wrong perhaps in the light of other work I have cited.
https://data.giss.nasa.gov/modelforce/
But now I am bored with your foolishness.
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Comment on Week in review – science edition by edimbukvarevic
JCH, stay tuned. The AGW hypothesis is so bad, it will be beaten by reading tea leaves.
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Comment on Week in review – science edition by JCH
Stay tuned. Right around the coroner. Could be happening right now. But the ice? But the snow?
Lol.
I have heard this tune since 2007.
The level of atmospheric CO2 is the primary control knob of the climate, which is why the PDO and the AMO add up to around zero in the instrument record. When the anthropogenic component was small, it could get pushed around. Take a look. It’s been a long time since any puny oscillation has stunned the gorilla.
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Comment on Week in review – science edition by edimbukvarevic
Now, that is nonsense! AMO is already detrended. If you detrend the GMO, you get the same.
http://www.woodfortrees.org/plot/hadcrut4gl/detrend:0.87/trend/plot/hadcrut4gl/compress:12
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Comment on Week in review – science edition by JCH
Of course you do. Since around 1960, the AMO is the slave of the GMST.
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Comment on Week in review – science edition by Robert I. Ellison
Oceans are the great heat engine of the planet – and heat in oceans is modulated by – inter alia – SW changes over the upwelling regions of the eastern Pacific. Shown below in a correlation between cumulative MEI and surface temperature.
There is a longer comment below that includes some discussion from – inter alia – this Sergei Kravtsov et al study. Sergei’s gravitas eclipses that of JCH by an elephant to a pissant.
https://www.researchgate.net/scientific-contributions/2037436895_Sergey_Kravtsov
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Comment on Week in review – science edition by cerescokid
I’ll hold my powder until the Arctic Sea Ice begins to recover. Even now there is a little glimmer of SST cooling. In the meantime. Tick tock. Tick Tock.
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Comment on Week in review – science edition by JCH
Which oscillation looks like it may have caused mid-century cooling?
Which oscillation looks like it may have caused the pause in warming in the 21st century.
Answer – the PDO: the blue one.
What is the great 60-year AMO doing to the GMST. It crashes; the GMST doesn’t even notice. The GMST shoots up around 1970; the great and powerful AMO slavishly follows. What choice does it have? None. The North Atlantic is too small for it to be a global bully.
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Comment on Week in review – science edition by cerescokid
Bully is a little strong.
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Comment on Week in review – science edition by Robert I. Ellison
And the AMO and AMOC are – btw – slave to the Atlantic expression of the Arctic Oscillation.
Over the longer term – more negative as the sun dims.
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Comment on Week in review – science edition by cerescokid
Maybe not a bully but at least a bullyette, at least according to Moore et al
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Comment on Week in review – science edition by cerescokid
And it apparently affects East Asia
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0022740
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Comment on Week in review – science edition by cerescokid
You thinks AMO has pronounced influence across the globe.
https://www.ess.uci.edu/~yu/PDF/Lyu-and-Yu.GRL.2017.pdf
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Comment on Climate sensitivity to cumulative carbon emissions by Atomsk's Sanakan (@AtomsksSanakan)
Re: “Atomsk: The idea that estimates of climate sensitivity from “energy balance models” should not be characterized as “observationally-base” is politically-motivated nonsense.”
Funny, since I have no political position on AGW.
It’s “observationally-based” *and* “model-based”, since it uses observational analyses, an EBM, and GCMs. I’ve explained that already multiple times (including to you). No politics is needed for making that point.
Re: “Converting TCR into ECS is based on the law of conservation of energy, which is hardly a “model”.”
EBMs are not just based on conservation of energy. How many times do people need to explain this to you?
EBMs go beyond conservation of energy since, for example, they need to use a model to translate their estimate of effective climate sensitivity into ECS. You can’t simply do that based on conservation of energy, since climate sensitivity can increase as warming occurs due to changing feedbacks, without violating conservation of energy. The paleoclimate evidence supports the idea that climate sensitivity increases with the initial warming, as gone over in papers such as:
“Climate sensitivity in the geologic past”
So go back, and re-read what I quoted from Forster:
“Inference of climate sensitivity from analysis of Earth’s energy budget
[…]
Forster & Gregory (2006, p. 39) overstated the benefits of such an approach by claiming, “Importantly, the [ECS] estimate is completely independent of climate model results.” As Equation 1 derives directly from conservation of energy, the Forster & Gregory (2006) claim would appear valid. But it in fact makes the assumption that the α derived from a particular observational period is the same as the α applicable under long-term climate change. Another way of stating this assumption is saying that the effective climate sensitivity (the apparent ECS diagnosed from a specific α) is the same as the true ECS. Uncertainties around the derivation of ECS from an energy budget approach can be attributed to two causes: the model used to translate α into an ECS estimate and the quality of the observation-based data sets.”
Re: “The only assumption in energy balance models arises from internal (unforced) variability – chaos”
Once again, it’s like you don’t even read what you’re responding to. That is not all EBMs assume. Even the people who use EBM-based estimates (ex: Forster) admit that.
Re: “If AOGCMs are correct in their estimate of unforced variability, then their central estimates for climate sensitivity climate sensitivity are wrong.”
What you just wrote makes no sense.
Re: “All observationally-based experiments involve some sort of model. Observations of the rate of sea level rise are based a statistical linear AR1 model for the noise in the data. Do you call those “model-based estimates of SLR”?”
The difference is that I, unlike you, don’t go around falsely offering a false dichotomy between “observationally-based” estimates vs. “model-based” estimates. When EBM-based estimates are brought up, you always conveniently leave out the fact that they use models, so that you can saying they’re not like those IPCC estimates that use models. Sorry, but that’s not going to fly. Both approaches use models and both approaches use observations. Get over it.
Re: “Let’s state this more accurately: The central estimates for modeled climate sensitivity are larger than observed climate sensitivity over the past century. SOME models predict a significant increase in climate sensitivity over the next century and some do not.”
And you failed to state the relative proportion of models that do that, vs. those that don’t. We both know why.
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Comment on Climate sensitivity to cumulative carbon emissions by Atomsk's Sanakan (@AtomsksSanakan)
Re: “By far the best understood and most studied paleoclimate analysis is of the LGM-preindustrial Holocene transition. Estimating ECS from that transition using an energy budget model is a well established approach. Lewis & Curry (2018) shows that, using modern estimates of the forcing and global temperature change, doing so gives and ECS estimate of 1.76 C, in line with the paper’s main ECS estimate.”
Sorry, but I’m not just going to throw the vast majority of the literature on paleoclimate ECS estimates, just to support the low estimate of ECS you defend. That would be cherry-picking. The paleoclimate evidence supports a higher ECS estimate than you advocate, and one cannot simply cherry-pick your view on the LCM in order to defend a low estimate. People interested in more thorough, comprehensives review of the paleoclimate literature, can go read papers such as:
“Climate sensitivity in the geologic past”
“Beyond equilibrium climate sensitivity”
“Palaeoclimate constraints on the impact of 2 °C anthropogenic warming and beyond”
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Comment on Week in review – science edition by Robert I. Ellison
The Central Role of Ocean Dynamics in Connecting the North Atlantic Oscillation to the Extratropical Component of the Atlantic Multidecadal Oscillation – https://journals.ametsoc.org/doi/full/10.1175/JCLI-D-16-0358.1
SST in the north Atlantic have an impact on global hydrology – but it may be the broader globally coupled climate system that modulates Earth energy dynamics. And if you look at JCH’s wood for dimwits graph – compared with the tea leaves below – you can see bits of the global stadium wave.
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Comment on Climate sensitivity to cumulative carbon emissions by Atomsk's Sanakan (@AtomsksSanakan)
I forgot to cover something else.
Re: “In general usage, ‘models’ refers to GCMs/AOGCMs, but not to a single-equation zero-dimensional energy balance model.”
It might have that usage in “skeptic” blogs and such circles. But when I read the literature, I see EBMs referred to as models. Hence the “M” in “EBMs”. But if you want to use the terms in a particular way, then that’s fine with me, as long as you’re clear that you’re doing this.
Re: “By far the best understood and most studied paleoclimate analysis is of the LGM-preindustrial Holocene transition. Estimating ECS from that transition using an energy budget model is a well established approach. Lewis & Curry (2018) shows that, using modern estimates of the forcing and global temperature change, doing so gives and ECS estimate of 1.76 C, in line with the paper’s main ECS estimate.”
This is what your paper says:
“The impact of recent forcing and ocean heat uptake data on estimates of climate sensitivity
[…]
Reasonably thorough proxy-based estimates of changes in surface temperature (Annan et al. 2013: 4.0 K; Friedrich et al. 2016: 5.0 K) and forcings (Kohler et al. 2010: total 9.5 Wm−2) are available for the LGM transition. These values imply, using (4), an ECS estimate of 1.76 K (averaging the two surface temperature increase estimates and taking F 2x CO2 per AR5, since the WMGG forcings were derived using AR5 formulae), in line with the median obtained by scaling this study’s ECShist estimate.”
Friedrich et al. 2016 is:
“Nonlinear climate sensitivity and its implications for future greenhouse warming”
It’s covered in figure 3 of:
“Beyond equilibrium climate sensitivity”
Friedrich et al. 2016 (page 3) gives an ECS estimate of ~1.76K for colder conditions, and ~4.88K under warmer conditions. Thus it shows ECS increasing with warming. When they extend their results to future greenhouse warming conditions (page 3 of the paper) they use the latter estimate, not the former one. Hence, they end up with a different conclusion that you do with respect to the models and future warming. They write:
“On the basis of temperature data from eight glacial cycles, our results provide an independent validation of the magnitude of current CMIP5 warming projections.”
http://advances.sciencemag.org/content/advances/2/11/e1501923.full.pdf
You also cite “Annan et al. 2013” (Annan and Hargreaves), which is this paper:
“A new global reconstruction of temperature changes at the Last Glacial Maximum”
That paper notes:
“Our new temperature anomaly of 4.0 ± 0.8 ◦C, combined with estimated forcing of 6–11 W m−2 (Annan et al., 2005; Jansen et al., 2007) would suggest a median estimate for the equilibrium climate sensitivity of around 1.7 ◦C, with a 95% range of 1.2–2.4 ◦C. However, such a simplistic estimate is far from robust, as it ignores any asymmetry or nonlinearity which is thought to exist in the response to different forcings (Hargreaves et al., 2007; Yoshimori et al., 2011). The ratio between temperature anomalies obtained under LGM and doubled CO2 conditions found in previous modelling studies varies from 1.3 (Schmittner et al., 2011) to over 2 (Schneider von Deimling et al., 2006a). More recently, Hargreaves et al. (2012) used the relationship found in the PMIP2 ensemble between the tropical temperature change at the LGM, and equilibrium climate sensitivity, to estimate the equilibrium climate sensitivity to be around 2.5 ◦C with a high probability of lying under 4 ◦C, although this result is subject to several important caveats.”
So I don’t see how that really supports your ECS estimate of 1.76K, when they say such as result is simplistic and far from robust because it doesn’t adequately address just the sort of issues Dessler and others bring up regarding non-linear responses. In a subsequent 2015 paper, Annan and Hargreaves put the ECS value from LGM at around 2.5K, though they note that there are remaining uncertainties:
“A perspective on model-data surface temperature comparison at the Last Glacial Maximum”
And you cite “Kohler et al. 2010”, which is this paper:
“What caused Earth’s temperature variations during the last 800,000 years? Data-based evidence on radiative forcing and constraints on climate sensitivity”
That paper places ECS at around 2.4K, when “excluding the ice sheet and vegetation components”.
So even if we grant your cherry-picking of the LGM out of the wealth of paleoclimate evidence, and even if we just look at the sources you used to provide values to support your calculated estimate of 1.76K, we still end up with an ECS value greater than the 1.76K value you gave in your paper. This makes me even more confident that climate scientists like Dessler are right in rejecting your estimate. Your estimate is looking more and more like a low outlier.
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