Sentences with phrase «own equilibrium climate sensitivity»

Scientists call this responsiveness «equilibrium climate sensitivity» (ECS).

A leaked draft copy of the Intergovernmental Panel on Climate Change's fifth assessment report (AR5) surfaced earlier this summer and triggered a small tempest among climate bloggers, scientists and skeptics over revelations that a key metric, called the «Equilibrium Climate Sensitivity» (ECS), had been revised downward.

Does it mean that transient climate response (as expressed by ice sheet or see - ice melting among other events) to GHGs is not so far from equilibrium climate sensitivity?

Specifically, the draft report says that «equilibrium climate sensitivity» (ECS)-- eventual warming induced by a doubling of carbon dioxide in the atmosphere, which takes hundreds of years to occur — is «extremely likely» to be above 1 degree Celsius (1.8 degrees Fahrenheit), «likely» to be above 1.5 degrees Celsius (2.4 degrees Fahrenheit) and «very likely» to be below 6 degrees Celsius (10.8 Fahrenheit).

We have often made the case here that equilibrium climate sensitivity is most likely to be around 0.75 + / - 0.25 C / (W / m2)(corresponding to about a 3 °C rise for a doubling of CO2).

Beyond equilibrium climate sensitivity -LSB-...] Newer metrics relating global warming directly to the total emitted CO2 show that in order to keep warming to within 2 °C, future CO2 emissions have to remain strongly limited, irrespective of climate sensitivity being at the high or low end.»

From the article: «The most likely value of equilibrium climate sensitivity based on the energy budget of the most recent decade is 2.0 °C, with a 5 — 95 % confidence interval of 1.2 — 3.9 °C»

Forecast temperature trends for time scales of a few decades or less are not very sensitive to the model's equilibrium climate sensitivity (reference provided).

The real «equilibrium climate sensitivity,» which is the amount of global warming to be expected for a doubling of atmospheric CO2, is likely to be about 1 °C, some three times smaller than most models assumed.

Here's an interesting paper that is referenced in some of the listed publications: Meraner et al. 2013, Robust increase in equilibrium climate sensitivity under global warming, GRL https://hal.inria.fr/hal-01099395/document

There have been quite a number of papers published in recent years concerning «emergent constraints» on equilibrium climate sensitivity (ECS) in comprehensive global climate models (GCMs), of both the current (CMIP5) and previous (CMIP3) generations.

In Part 1 of this article the nature and validity of emergent constraints [1] on equilibrium climate sensitivity (ECS) in GCMs were discussed, drawing mainly on the analysis and assessment of 19 such constraints in Caldwell et al. (2018), [2] who concluded that only four of them were credible.

Yes, the discussion above is about equilibrium climate sensitivity and by picking 2100 (or 2011) we'll be measuring the transient climate sensitivity.

And further, in stating the year 2100 values, you are mixing up transient with equilibrium climate sensitivity.

In Part 1 of this article the nature and validity of emergent constraints [i] on equilibrium climate sensitivity (ECS) in GCMs were discussed, drawing mainly on the analysis and assessment of 19 such constraints in Caldwell et al (2018; henceforth Caldwell), [ii] who concluded that only four of them were credible.

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.

Then on page 9.5 we read «There is very high confidence that the primary factor contributing to the spread in equilibrium climate sensitivity continues to be the cloud feedback.

Inverse estimates of aerosol forcing from detection and attribution studies and studies estimating equilibrium climate sensitivity (see Section 9.6 and Table 9.3 for details on studies).

First let's define the «equilibrium climate sensitivity» as the «equilibrium change in global mean surface temperature following a doubling of the atmospheric (equivalent) CO2 concentration.

You can not use equilibrium climate sensitivity to estimate the response to an 11 year periodic forcing — precisely because it is not in equilibirum!

The 100 % anthropogenic attribution from climate models is derived from climate models that have an average equilibrium climate sensitivity (ECS) around 3C.

captdallas2 @ 130 — To become more impressed by the estimate of about 3 K for Charney equilibrium climate sensitivity, read papers by Annan & Hargreaves.

Your attempt to estimate equilibrium climate sensitivity from the 20th C won't work because a) the forcings are not that well known (so the error in your estimate is large), b) the climate is not in equilibrium — you need to account for the uptake of heat in the ocean at least.

It gets tricky now because the equilibrium climate sensitivity requires a timescale to be defined — barring large hysteresis, it isn't so large going out many millions of years (weathering feedback); there will be a time scale of maximum sensitivity.

The notion that the response to Pinatubo can determine equilibrium climate sensitivity is rather odd, and is not supported by evidence.

At equilibrium, T» is constant and equal to Teq», so G * Teq» = For», thus Teq» = For» / G, so that equilibrium climate sensitivity = 1 / G (perhaps G could be called the climate «insensitivity»).

The true equilibrium climate sensitivity for the climate models used in this demonstration is in the range 2.1 — 4.4, and the transient climate sensitivity is 1.2 — 2.6 (IPCC AR5, Table 8.2).

Annan said equilibrium climate sensitivity is unlikely to be higher than 4.5 °C — there are few if any mainstream climate scientists who would disagree with this.

Nonetheless, there is a tendency for similar equilibrium climate sensitivity ECS, especially using a Charney ECS defined as equilibrium global time average surface temperature change per unit tropopause - level forcing with stratospheric adjustment, for different types of forcings (CO2, CH4, solar) if the forcings are not too idiosyncratic.

DDS 1: «The claim of reduced uncertainty for equilibrium climate sensitivity is premature» This is what many climate skeptics have been saying for years and they have been called deniers for their efforts.

Equilibrium climate sensitivity describes how much the planet will warm if carbon dioxide levels were to double, and the Earth goes on to cope and stabilize to the new atmosphere.

That forcing is just under 4W / m ^ 2, so put differently, equilibrium climate sensitivity is the equilibrium expected surface warming for a radiative forcing of 1W / m ^ 2, divided by 4.

If it is correct, then the term Equilibrium Climate Sensitivity would surely be a misnomer, in that no predictable equilibrium is achieved.

Regarding ECS («equilibrium climate sensitivity»), I think there are difficulties estimating anything truly resembling a Charney - type ECS from data involving OHC uptake and forcing estimates, because these estimates are fraught with so many uncertainties, and because the values that are calculated, even if accurate, bear an uncertain relationship to how the climate would behave at equilibrium.

In this case the CO2 concentration is instantaneously quadrupled and kept constant for 150 years of simulation, and both equilibrium climate sensitivity and RF are diagnosed from a linear fit of perturbations in global mean surface temperature to the instantaneous radiative imbalance at the TOA.

What could hypothetically happen if a very large change in GHG amount / type is made, is that the forcing could increase beyond a point where it becomes saturated at the tropopause level at all wavelengths — what can happen then is that the equilibrium climate sensitivity to the nearly zero forcing from additional GHGs may approach infinity, because in equilibrium the tropopause has to shift upward enough to reach a level where there can be some net LW flux up through it.

Each climate model has its own equilibrium climate sensitivity.

Cox et al.'s calculations of the equilibrium climate sensitivity used a key metric which was derived from the Hasselmann model and assumed a constant C:.

Is there some simple intuitive explanation of how this pipeline warming is estimated with respect to an equilibrium climate sensitivity at a doubling of CO2 equivalent (thus including methane, ozone, aerosols, CFCs...)?

The feedback can become zero — or to avoid confusion regarding what is and is not a feedback — the equilibrium climate sensitivity can become infinite (or negative) in some conditions.

«Forecast temperature trends for time scales of a few decades or less are not very sensitive to the model's equilibrium climate sensitivity (reference provided).

Climate reconstructions for the warm periods of the Cenozoic also provide an opportunity to assess Earth - system and equilibrium climate sensitivities.

part of the utility is that Charney sensitivity, using only relatively rapid feedbacks, describes the climate response to an externally imposed forcing change on a particular timescale related to the heat capacity of the system (if the feedbacks were sufficiniently rapid and the heat capacity independent of time scale (it's not largely because of oceanic circulation), an imbalance would exponentially decay on the time scale of heat capacity * Charney equilibrium climate sensitivity.

But I would suppose that equilibrium climate sensitivity [background] and even global mean surface temperature on a decadal scale could be better nailed down by model pruning and better ocean data.

But so does the equilibrium climate sensitivity, only after the forcing ceases, e.g., we quite raising CO2 concentrations with our emissions.

But 3,2 °C is the best estimate for equilibrium climate sensitivity (that is when the runs of models consider all the feedbacks).

By focusing soley on the equilibrium climate sensitivity, the authors do miss a lot of features important to people about the overall climate system — for example, what's the equilibrium sensitivity of the carbon cycle to the temperature change brought about by 2X CO2?

(Actually, I believe what you are refering to, is as your link pointed out, the IPCC definition of equilibrium climate sensitivity, and not simple solar radiative equilibrium, as we have been discussing in these last few posts.)

These additional feedbacks are not still accounted by GCM models, at least those used in IPCC 2007 for equilibrium climate sensitivity.

If I am right, then correct processing of the data used in Forest 2006 would lead to the conclusion that equilibrium climate sensitivity (to a doubling of CO2 in the atmosphere) is close to 1 °C, not 3 °C, implying that likely future warming has been grossly overestimated by the IPCC.