Sentences with phrase «effective climate sensitivity of»

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.

The lower value — which conforms rather more closely with mainstream thinking than the higher value yields an effective climate sensitivity of ca 1.5 deg K for a doubling of CO2, which gets fairly close to ZDM estimates using historical forcing, temperature and ocean heat data.»

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.

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

Along with the corrected value of F2xCO2 being higher than the one used in the paper, and the correct comparison being with the model's effective climate sensitivity of ~ 2.0 C, this results in a higher estimate of equilibrium efficacy from Historical total forcing.

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.

Not exact matches

Where (equilibrium / effective) climate sensitivity (S) is the only parameter being estimated, and the estimation method works directly from the observed variables (e.g., by regression, as in Forster and Gregory, 2006, or mean estimation, as in Gregory et al, 2002) over the instrumental period, then the JP for S will be almost of the form 1 / S ^ 2.

They conclude, based on study of CMIP5 model output, that equilibrium climate sensitivity (ECS) is not a fixed quantity — as temperatures increase, the response is nonlinear, with a smaller effective ECS in the first decades of the experiments, increasing over time.

My main criticism of their study is that they have calculated effective climate sensitivity (their ICS) on a basis which is wrong for ICS in GCMs; their basis is also inconsistent with observationally - based estimates of ICS.

Are there simple, controlled laboratory experiments that could either shed light on climate sensitivity and / or else help demonstrate, including mostly to skeptics, how changes in trace concentrations of an IR absorber / re-radiator are so effective at changing the temp of a system?

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

A detailed reanalysis is presented of a «Bayesian» climate parameter study (Forest et al., 2006) that estimates climate sensitivity (ECS) jointly with effective ocean diffusivity and aerosol forcing, using optimal fingerprints to compare multi-decadal observations with simulations by the MIT 2D climate model at varying settings of the three climate parameters.

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

Depending on meridional heat transport, when freezing temperatures reach deep enough towards low - latitudes, the ice - albedo feedback can become so effective that climate sensitivity becomes infinite and even negative (implying unstable equilibrium for any «ice - line» (latitude marking the edge of ice) between the equator and some other latitude).

My main criticism of their study is that they have calculated effective climate sensitivity (their ICS) on a basis which is wrong for ICS in GCMs; their basis is also inconsistent with observationally - based estimates of ICS.

Hansen's paper adds in the possibility of ice sheet response in the relatively near term (centuries, if not decades), which leads to an effective doubling of the sensitivity of climate to our CO2 increase.

Are there simple, controlled laboratory experiments that could either shed light on climate sensitivity and / or else help demonstrate, including mostly to skeptics, how changes in trace concentrations of an IR absorber / re-radiator are so effective at changing the temp of a system?

Unfortunately, there are many factors that preclude an effective bound on the risks — ranging from uncertainties in downscaling to more fundamental issues such as the uncertainty of climate sensitivity.

At least with a model like the MIT one used in Forest 2006 one can (if the descriptions of it are correct) set the key climate sensitivity, effective ocean diffusivity and aerosol forcing levels independently and with some confidence (I'm not the person to ask how much) that the simulated results reflect those settings.

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.

It is described by Here, a1 is a fixed heat capacity, which we approximate as the effective heat capacity per unit area of a 75 m ocean mixed layer; a3 corresponds to a doubling of atmospheric CO2 levels causing a forcing of 3.74 W m − 2; and C0 is the pre-industrial concentration of CO2 [30]; a0 and a2 are both able to vary, and control the climate sensitivity, and rate of advection of heat through the thermocline, respectively.

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

The «flaw» of low - ECS climate model studies may not be so much in aerosols, the NASA study suggests, as the effective radiative forcing scenario (with high climate sensitivity) is accompanied with relatively low value for aerosol efficacy:

As a result, the study would provide little evidence that historical period observational estimates of ECS have been biased low in relation to effective climate sensitivity.

At any reasonable level of the latter (i.e., a plausible effective climate sensitivity value), the OHC data can't be reconciled with more than a small contribution from internal variability.

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.

Which would, of course, imply an absurdly high effective climate sensitivity.

This will clearly result in more papers trying to explain this fact on subjects such as climate sensitivity, as well as whether or not CFCs caused more warming than originally thought, radiation of heat into space as earth's effective temperature increases, and whether the saturation of absorption of EMR by CO2 in the atmosphere actually fits the logrithmic curve.

It states: ``... measures of model fidelity that are effective at narrowing the distribution of future projections... may be poor measures of the likelihood that a model will provide an accurate estimate of climate sensitivity.»

They conclude, based on study of CMIP5 model output, that equilibrium climate sensitivity (ECS) is not a fixed quantity — as temperatures increase, the response is nonlinear, with a smaller effective ECS in the first decades of the experiments, increasing over time.

Where (equilibrium / effective) climate sensitivity (S) is the only parameter being estimated, and the estimation method works directly from the observed variables (e.g., by regression, as in Forster and Gregory, 2006, or mean estimation, as in Gregory et al, 2002) over the instrumental period, then the JP for S will be almost of the form 1 / S ^ 2.

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.

Stipulating, of course, that adaptation might be a more cost - effective private policy for you, even if climate sensitivity ends up to be above the modal estimate.

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).

Estimates based on recent observations can only be of effective, not equilibrium, climate sensitivity, since the climate system has not reached equilibrium.

The central conclusion of this study is that to disregard the low values of effective climate sensitivity (≈ 1 °C) given by observations on the grounds that they do not agree with the larger values of equilibrium, or effective, climate sensitivity given by GCMs, while the GCMs themselves do not properly represent the observed value of the tropical radiative response coefficient, is a standpoint that needs to be reconsidered.

Estimates of effective climate sensitivity (EfCS) are the corresponding quantities obtained using transient GCM output or observations.

I have to admit, having not initially read the paper, I took Bates» EfCS to be the equivalent of TCR, taking my cue from his description «Estimates of effective climate sensitivity (EfCS) are the corresponding quantities obtained using TRANSIENT GCM output or observations».

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.

I have, incidentally, found using a multilayer diffusive ocean model that there is a near complete identity in the path of the model surface temperature response to a step forcing, for the better part of a century, over a wide range of equilibrium climate sensitivities if effective ocean diffusivity is varied to compensate.

[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.

For equilibrium efficacies, I show estimates both from the raw data (save for iRF), and with the ocean heat uptake ΔQ divided by 0.86 to estimate the full TOA imbalance ΔN and the GISS - E2 - R equilibrium climate sensitivity of 2.3 °C replaced by its effective climate sensitivity, taken as 2.0 °C.