It does not equate to total warming. It equates to total warming divided by radiative forcing. I don't think you seem to be grasping this.
no - you're still equating an end result... to total warming. That's not what climate sensitivity is; by saying so you're, for example, foregoing additional warming due to additional emissions (beyond doubling)... by saying so you're, for example, foregoing additional warming due to long-term feedback influences.
The equilibrium condition (ECS) is idealized, not real. It is the theoretical amount of warming we would get if emissions stopped tomorrow and we allowed the system to reach homeostasis, based on the results of the models. The transient response, on the other, can be calculated based on observations.
"idealized", or not, ECS is the de-facto go-to reference when sensitivity is spoken of... unless, as I emphasized in asking you to clarify just what sensitivity you were speaking to, qualification is added. ECS can also be calculated based on observations... you yourself offered suggestion to that end with a mention to the wiki example.
You seem to be stuck in binary more here (TCR or ECS) when it should be treated as a continuum, with TCR and ECS being a convenient differentiation for certain purposes.
no - not 'stuck'; it is important, obviously, to know what sensitivity is being spoken of/to... again, which is why I pressed you in that regard and emphasized you weren't speaking of how you presumed to interpret your transient estimate.
The estimate figures I've stated are not in context to my reference to ECS. For the fifth or sixth time now: the estimate figures I've stated are in reference to solving for lambda in the above equation.
I quoted your statements, verbatim... where you speak to an estimate while at the same time also speaking to facets that only apply to ECS. I don't see how I can separate the two. You presume to speak of the base formula without actually interpreting what it means (to you) or how you would presume to associate it to say, policy attachments related to the shorter-term time frame that transient implies.
The reference to the critical point and the transition state are, as stated, my guess, based on my studies of complex systems. That's what I think will happen, but who knows? Conversely, the observed climate sensitivity to date is not a guess.
but again, this is you mixing terminology across the respective sensitivities..... to which you suggest I'm in "binary mode" (TCR or ECS). You can call it that if you'd like; I'm just going to continue to state you can't be presuming to call your estimate transient and then at the same time, without qualifying a distinction, bring forward facets only related to ECS.
Correct.
There are a number of factors it doesn't take into account. It's based on the instrumental record for temperatures and the concentration of CO2. Ocean heat uptake may push it up a bit. Other factors that I haven't accounted for may push it down.
my point exactly! As much as you continue to stick to a rigid attachment to the base formula, there are many forcings other than just CO2.... and there's ocean heat uptake, which I mentioned, that the base formula doesn't (directly) include. Which, again, given how you only repeatedly spoke of temp and CO2, was why I pressed you as to how you were actually arriving at your estimate.
You are reading too much into it then. I've simply calculated the climate sensitivity based on the instrumetnal record. I'm not seeking anything, or trying to explain anything.
then what's the point? As I mentioned, one of the key reasons to look to transient is in regards to shorter-term policy direction/implication. As I mentioned, it appears, to me, the only reason you've taken your estimate approach is one to align with the lowest of the low sensitivity figures... and, at the same time, repeatedly point out you don't accept the IPCC estimate ranges. And you're doing this all in the face of self-acknowledged uncertainty and unknowns. In my personal positioning I can accept eliminating the high-end (the so-called "alarmist" high-end sensitivities in the 5-to-6+ °C level... but it also means "throwing out" those low-end estimates, as well. Given the profile emphasis scientists now have on sensitivity, we're seeing publication updates regularly... and I'm still seeing those estimates coming in at the 'mid-point' of the IPCC estimate range (and higher)... and yes, along with those presenting lower-end results.
Observed temperatures have not increased with the mean of the model projections used by the IPCC, so I'm not exactly going out on a limb by saying that the climate sensitivity is at the lower bound of the IPCC estimates.
Hey, I've even got a chart!
are you interpreting that graphic correctly? Notwithstanding it's 'masked data' (as in the absence of data if not present; i.e., no infilling as exists in, for example, GISS or the same HadCrut4 with Cowtan/Way kriging/hybridization), the observed global surface temperatures are still within the 90% (5–95%) confidence interval of model runs. A different baseline, different temperature dataset, and a different chosen emission scenario would bring forward a different result... meaning, there are chosen dependencies within that graphic. Here's another graphic for consideration; CMIP3 models, varying temperature datasets, and a selected emission scenario:
or... from the same source your graphic originates from :
Updated version of IPCC AR5 Figure 11.25 with provisional data for 2013 from HadCRUT4 (black & red) and addition of Cowtan & Way global temperature timeseries (blue). The CMIP5 model projections are shown relative to 1986-2005 (light grey) and 2006-2012 (dark grey). The red hatching is the IPCC AR5 assessed likely range for global temperatures in the 2016-2035 period.
