Sentences with phrase «effective climate sensitivity»

Although below the model ECS of 2.3 C, that is very close to the GISS - E2 - R effective climate sensitivity of ~ 2 C, which is what this method would estimate if the forcing were purely from CO2.

But what I actually wrote was that in GISS - E2 - R effective climate sensitivity increases with time since the forcing was applied, as it does in many GCMs.

In particular, «[t] hese 19 tuned simple model versions have effective climate sensitivities in the range 1.9 °C to 5.9 °C.»

The IPCC's Fifth Assessment Report shows a range of figures for effective climate sensitivity — the amount of warming that can be expected from a doubling of carbon dioxide levels.

Results are shown for various models in Figure 9.20 It is evident that the models with high effective climate sensitivity also tend to have a large net heat flux into the ocean.

The evident relationship between effective climate sensitivity and ocean heat uptake leads to the transient climate response (TCR) having a smaller spread among the model results than the climate models climate sensitivity alone would suggest (see Section 9.3.1).

We can say that the GCM results (using the same input forcings and the same modeled temperature outputs) can be matched with a zero - dimensional model with low effective climate sensitivity.

While effective climate sensitivity is smaller than ECS in many GCMs, it is not known whether that is the case in the real climate system, and MEA15 has nothing to contribute on this question.

This is at least in part due to the fact that the HadCM2 effective climate sensitivity increases with time (see Section 9.3.4.1).

[8] I estimate GISS - E2 - R's effective climate sensitivity applicable to the historical period as 1.9 °C and its ERF F2xCO2 as 4.5 Wm − 2, implying a climate feedback parameter of 2.37 Wm − 2 K − 1, based on a standard Gregory plot regression of (ΔF − ΔN) on ΔT for 35 years following an abrupt quadrupling of CO2 concentration.

It is possible that effective climate sensitivity increases over time (ignoring, as for equilibrium sensitivity, ice sheet and other slow feedbacks), but there is currently no model - independent reason to think that it does so.

This is of particular interest in relation to «effective climate sensitivity» estimates that rely heavily on OHC uptake data.

My preference would be to refer to these as estimates of «effective climate sensitivity» rather than ECS.

[Response: Our interest in the «effective climate sensitivity» is very close to zero.

So there is no evidence that effective climate sensitivity is materially underestimated when using historical observations.

Although the model's ECS is underestimated, that is only because its effective climate sensitivity increases over time.

Rather, they were calculated from the GMST response of CMIP5 models, their effective climate sensitivity parameters and their radiative imbalances.

Gavin Schmidt's paraphrasing states that effective climate sensitivity is smaller than ECS.

The effective climate sensitivity is a related measure that circumvents the requirement of equilibrium.

Accordingly, the forcing estimation method relies upon a model exhibiting a fairly linear climate response, and hence having a climate feedback parameter (and an effective climate sensitivity) that does not vary with time (in addition to having a temperature response that is proportional to forcing).

That a robust behaviour in models of apparent (effective) climate sensitivity being lower in the early years after a forcing is imposed than subsequently, rather than remaining constant, requires multiplying estimates of climate sensitivity by a further factor of ~ 1.25 in order to convert what they actually estimate (effective climate sensitivity) to ECS.

The ECS values should be compared with the model's effective climate sensitivity of 1.9 — 2.0 °C.

And with ΔQ divided by 0.86 to better approximate ΔN, the ECS estimate is 2.02 °C, in line with GISS - E2 - R's effective climate sensitivity of 1.9 — 2.0 °C.

HadCM2, which has an effective climate sensitivity in the middle of the IPCC range (Table 9.1), was run with the S550 ppm and S750 ppm stabilisation profiles (S profiles; Enting et al., 1994; Schimel et al., 1997).

The effective climate sensitivities around the time of CO2 doubling (average for the years 61 to 80), when the signal is strongest, agree reasonably well with the mixed - layer equilibrium climate sensitivities given in Figure 9.20.

The relationship between the effective climate sensitivity and the oceanic heat uptake was first described by Hansen et al. (1984, 1985) using a box diffusion model.

The effective climate sensitivity and ocean heat uptake are compared by Raper et al. (2001b) using the CMIP2 data set (1 % / yr CO2 increase to doubling).

Details of the individual model s sub-grid scale parametrizations also affect both the effective climate sensitivity and the oceanic heat uptake (Weaver and Wiebe, 1999).

Values are shown for the effective climate sensitivity, the net heat flux across the ocean surface multiplied by the ocean fraction and the global mean temperature change (TCR).

They do so in many coupled GCMs; in GISS - E2 - R the effective climate sensitivity relevant to Historical forcing is ~ 85 % of the equilibrium value.

When zero - intercept regressions are used for estimation, the transient efficacy of Historical iRF is then 1.02, and the equilibrium efficacy is also 1.02 (1.09 with ΔQ divided by 0.86), based on an effective climate sensitivity of 2.0 °C for the model.