Sentences with phrase «equilibrium climate sensitivity]»

In this context, the statement in REA16 that they do not calculate equilibrium climate sensitivity (ECS) «to avoid the assumption of linear climate response» is peculiar: they have already made this assumption in deriving model forcings.

«From the corresponding paper: «our study says nothing about the equilibrium climate sensitivity; it only suggests that the equilibrium greenhouse sensitivity is zero.»

The first stage of the experiment involves spinning up each version of the model to be as close to its own equilibrium climate state as possible.

L&S estimate the equilibrium climate sensitivity to doubled CO2 from their model at «about 1 - 1.5 °C or less».

Climate sensitivity - In Intergovernmental Panel on Climate Change (IPCC) reports, equilibrium climate sensitivity refers to the equilibrium change in the annual mean global surface temperature following a doubling of the atmospheric equivalent carbon dioxide concentration.

Hector — I didn't quite say «easily solved», but the Transient Climate Response (TCR) can serve as a useful approximation to equilibrium climate sensitivity, and moreover, may be of greater practical use, since it predicts climate responses over the course of decades rather than those that might eventuate one thousand years later.

Energy budget estimates of equilibrium climate sensitivity (ECS) and transient climate response (TCR) are derived based on the best estimates and uncertainty ranges for forcing provided in the IPCC Fifth Assessment Scientific Report (AR5).

The statement which was made regarding atmospheric cooling, is from NASA, and not Columbia University: «To quantify climate change, researchers need to know the Transient Climate Response (TCR) and Equilibrium Climate Sensitivity (ECS) of Earth.

Incomplete understanding of three key properties of the climate system — equilibrium climate sensitivity, rate of ocean heat uptake and historical aerosol forcing — and their underlying physical processes lead to uncertainties in our assessment of the global - mean temperature evolution in the twenty - first century 1,2 6.

- we lack a timescale short enough to consider the forcing as fixed (volcano, CO2 emissions, TSI variations) but long enough to get meaningful climate average (even if such average makes sense, that climate is only weakly chaotic) and certainly too short to reach equilibrium T. Equilibrium climate sensitivity is thus a purely theoretical construct not much more related to reality than the no - feedback sensitivity...

The potential change in the radiative restoration strength over longer timescales is also considered, resulting in a likely (67 %) range of 1.5 — 2.9 K for equilibrium climate sensitivity, and a 90 % confidence interval of 1.2 — 5.1 K

The assumption of AGW is manifested in the non-falsifiable theory that the equilibrium climate sensitivity (TECS) is a physical constant.

This claim is equivalent to the hypothesis that the equilibrium climate sensitivity (TECS) is a physical constant.

«Results imply that global and regional warming rates depend sensitively on regional ocean processes setting the [ocean heat uptake] pattern, and that equilibrium climate sensitivity can not be reliably estimated from transient observations.»

Other studies (Forest et al. 2002; Knutti et al. 2003) have assumed a prior that is uniformly distributed in equilibrium climate sensitivity, which is proportional to 1 / Y.

My first thought on reading the FG paper was, how well could they derive equilibrium climate sensitivity from such a short time period (15 years)?

Practically, more deep - ocean involvement does have an effect on equilibrium climate sensitivity, but it has a much larger effect on transient climate sensitivity (which is a more relevant parameter for discussions of anthropogenically forced climate change).

Meehl et al. [2007] report that the 5 — 95 % range of equilibrium climate sensitivity in CMIP3 models is 2.1 — 4.4 K. Over the last three decades, a lot of attention has been given to ΔT2x but it is still relatively poorly constrained.

In the Working Group 1: The Physical Science Basis Report of AR4 («AR4: WG1»), various studies deriving estimates of equilibrium climate sensitivity from observational data are cited, and a comparison of the results of many of these studies is shown in Figure 9.20, reproduced below.

Junkink: What you've said is not quite right for while a particular value of the equilibrium climate sensitivity possesses a probability density, under the IPCC's model, it does not possess a probability.

In summary, paleoclimate studies provide one line of evidence that supports an equilibrium climate sensitivity between about 2 and 4.5 °C, and the GWPF justification for dismissing these estimates is weak.

MAGICC gives the average of the GCM used by the IPCC, and assumes a 3 C equilibrium climate sensitivity (ECS).

However, the GWPF report only references the «main results» of Aldrin et al. (2012), whose study actually estimated equilibrium climate sensitivity of about 2.5 or 3.3 °C when accounting for cloud and indirect aerosol effects.

But, nevertheless, Lewis and Curry have generated a very robust observation - based estimate of the equilibrium climate sensitivity.

In summary, GCMs provide another line of evidence that generally supports an equilibrium climate sensitivity between about 2 and 4.5 °C, and the GWPF justification for dismissing these estimates is incorrect.

Because this is a fascinating subject, and equilibrium climate sensitivity (ECS) is contentious, I thought I'd summarize my impressions from the discussion so far.

''... had the IPCC FAR correctly projected the changes in atmospheric GHG from 1990 to 2011, their «best estimate» model with a 2.5 °C equilibrium climate sensitivity would have projected the ensuing global warming very accurately»

The flat prior PDF is an example of a non-informative prior; it is non-informative about the numerical value of the equilibrium climate sensitivity within the range of equilibrium climate sensitivities in which the probability density is constant and not nil.

However, Curry has no publications or expertise in this area, and once said that the global equilibrium climate sensitivity could fall anywhere between 0 and 10 °C for doubled CO2.

Therefore, estimating equilibrium climate sensitivity based on measurements of a climate that's out of equilibrium requires making some significant assumptions, for example that feedbacks will remain constant over time.

The success of the Hall and Qu study paved the way for a number of studies seeking emergent constraints for equilibrium climate sensitivity (ECS).

No: that is the beauty of using top of atmosphere radiative balance data — it automatically reflects the flow of heat into the ocean, so thermal inertia of the oceans is irrelevant to the estimate of equilibrium climate sensitivity that it provides, unlike with virtally all other instrumental methods.

seems to make any analysis with a linear dependence on global mean surface temperature suspect I suppose I should also add, for the purpose of analyzing equilibrium climate sensitivity — there may be other questions relating to short timescale processes where it may still be useful..

Compared with our prior, theirs emphasizes the higher values of equilibrium climate sensitivity.

It follows from the above proof that the problem of determination of the prior and posterior probability density functions belonging to the equilibrium climate sensitivity lacks a solution.

On the contrary, the authors stated that to show the robustness of the main conclusion of the paper — a relatively small equilibrium climate sensitivity — they deliberately adopted the regression model that gave the highest climate sensitivity.

Various paleoclimate - based equilibrium climate sensitivity estimates from a range of geologic time periods.

Thus, a prior is a possibility for which the probability is high of a low equilibrium climate sensitivity.

The study estimated with 68 percent probability that the equivalent equilibrium climate sensitivity is between 2.2 and 4.8 °C for a doubling of CO2, generally consistent with IPCC estimates, and inconsistent with the lower estimates preferred by GWPF.

«The equilibrium climate sensitivity ΔT2x = F2x / a is the warming in a steady state under 2xCO2, as discussed in section 1.

The entity that possesses a probability is an interval in the equilibrium climate sensitivity, e.g., the interval that is bounded by 2 and 3.

However, observable properties of the climate system do not necessarily scale with equilibrium climate sensitivity (Frame et al., 2005).

Speculations about the magnitude of the equilibrium climate sensitivity are useless for the purpose of making policy decisions.

Imposing a flat prior on an observable property, such as the climate feedback or transient climate response, is equivalent to imposing a highly skewed prior on the equilibrium climate sensitivity, and therefore results in narrower posterior likelihood ranges on the climate sensitivity that exclude very high sensitivities.

As I have just shown, the IPCC's procedure for extraction of a probability density function over the equilibrium climate sensitivity is illogical.

The IPCC AR5 stated that the equilibrium climate sensitivity is likely in the range 1.5 °C to 4.5 °C, in the First Order Draft it stated that «mostly likely value» being 3.0 °C.

And it should be possible to measure zero feedback equilibrium climate sensitivity on a small scale if not on a planetary one.

«Climate sensitivity estimates are greatly impacted by such variability especially when the observed record is used to try to place limits on equilibrium climate sensitivity [Otto et al., 2013], and simply using the ORAS - 4 estimates of OHC changes in the 2000s instead of those used by Otto... changes their computed equilibrium climate sensitivity from 2.0 °C to 2.5 °C, for instance.

The only meaning in a genuine change in the rate of warming is that the longer term trend provides a slight change in evidence for equilibrium climate sensitivity — perhaps there was more «internal variability» associated with some of the late C20 temperature rise...

In contrast, a probability density function over the equilibrium climate sensitivity conveys no information to a maker of public policy regarding the outcomes from his / her policy decisions.