Sentences with phrase «c climate sensitivity»

21st century warming using the 1.2 C climate sensitivity they have to use to replicate 20th century warming, then they will show only about a third as much 21st century warming as they actually do.

See my blog entry, it works out perfectly when including thermal inertia and the generally accepted range for aerosol forcing, ie it's in agreement with the 1.5C - 4.5 C climate sensitivity consensus.

I would expect that, if Lewis really thinks that his estimate of 1.6 C climate sensitivity is relevant, that he would at least write a decent scientific paper on that and get it reviewed and published.

It doesn't make a great difference, but I'll try again: the missing words in my first comment before «1 ° C «were: `... less than 2 ° C climate sensitivity.

As this is directly on topic here, I'd be curious to hear your source for confidence on < 2 ° C climate sensitivity.

Where I wrote PDA's question (first comment on this post): «As this is directly on topic here, I'd be curious to hear your source for confidence on 1 ° C climate sensitivity.»

C climate sensitivity if the observed history of ENSO was included, which was shown from CERES satellite measurements to modulate the Earth's radiative budget naturally (what we called «internal radiative forcing» of the climate system).

The IPCC gets its 2 - 4.5 C climate sensitivity range from Table 8.2 of the AR4, which lists 19 climate model - derived equilibrium sensitivity estimates that have a mean of 3.2 C and a standard deviation of 0.7 C.

If the 3 C climate sensitivity value were to prove correct, then that would imply global warming of between 1.5 and 3 degrees Celsius.

Please show me where I have stated that I «don't believe Nic Lewis's conclusion of 1.6C - 1.7 C climate sensitivity after - all» as I do not recall ever having said that.

Not exact matches

From this, they could estimate the climate sensitivity and the result was that where it was about 4.5 degrees C before the PETM, the temperature rose to about 5.1 degrees during the PETM.

Let us hope that a lower climate sensitivity of 2.5 degrees C turns out to be correct.

The conclusion that limiting CO2 below 450 ppm will prevent warming beyond two degrees C is based on a conservative definition of climate sensitivity that considers only the so - called fast feedbacks in the climate system, such as changes in clouds, water vapor and melting sea ice.

The upper limit of the range remains the same in both reports — 4.5 C (8.1 F)-- he noted, while most mainstream scientists put their «best guess» for climate sensitivity somewhere in the middle of the range, between 2.5 and 3.5 C.

«If the true climate sensitivity really is as high as 5 degrees C -LSB-(9 degrees F)-RSB-, the only way our descendants will find that out is if they stubbornly hold greenhouse gas concentrations constant for centuries at our target stabilization level.»

The IPCC wishes to destroy the world economy and starve the world of energy and food at a cost of $ 76 trillion over the next 40 year's (UN estimate), to keep global temps below 2C, when even their wildly pessimistic and disconfirmed projections (formally known as predictions) now suggest that climate sensitivity could be as low as 1.5 C, without spending a dime.

In international assessments of the climate issue, the consensus - estimate of 1.5 degrees C to 4.5 degrees C for climate sensitivity has remained unchanged for two decades.

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).

[Response: The ECHO - G model has a climate sensitivity that is within the standard range of the models considered by IPCC (around 2.6 deg C for 2xCO2 I think).

Such studies can reasonably account for the observed variations as a response to solar and volcanic forcing (and a few secondary things) with energy balance climate models tuned to have a climate sensitivity equivalent to 2.5 C per doubling of CO2.

This version of the model had a climate sensitivity was around 4 deg C for a doubling of CO2.

Therefore climate sensitivity would have to be much smaller than 4.2 C, say 1.5 to 2 C, in order for us to modify our conclusions significantly.

(where T = temperature, f = feedback factor and F a Flux or Forcing and C is the baseline climate sensitivity i.e. for a clear atmosphere)

The rest of the climate sensitivity above the about 1 degree C is tied to the obvious questions: where does the CO2 come from, and where does it go, and over what time period.

IPCC finds it essentially impossible (yeah, I know, highly unlikely or whatever) that the climate sensitivity could be less than 1.5 degrees C for doubling CO2, and 3 degrees C is a best - guess value.

Then, if you scale the Antarctic temperature change to a global temperature change, then the global climate sensitivity to a doubling of CO2 becomes 2 - 3 degrees C, perfectly in line with the climate sensitivity given by IPCC (and known from Arrhenius's calculations more than 100 years ago).

In 1987 and again in 1997 (referred to here), Michaels claimed that climate sensitivity was between 1.0 and 1.5 deg C (for a doubling of CO2), thus projected increases of GHGs would only lead to a small change.

Olympus Mons, What it would take is a new model that explained climate better than the current one and a) had a CO2 sensitivity lower than 1 degree per doubling; or b) had a large negative feedback that somehow kicked in right at the current terrestrial temperature range; or c) had a mechanism whereby CO2 suddenly stopped being a greenhouse gas at 280 ppmv

(c) Our current climate models can not replicate the relatively high climate sensitivities, and Arctic Amplifications, of Super Interglacial periods, which are most relevant to our future in 2100;

[Response: Your correspondent can't possibly believe that climate sensitivity is zero (due to some magical stabilisation mechanism) and also claim that the sensitivity to solar is enough to explain the 20th C trend.

Assuming a climate sensitivity of 0.7 K / W / m ^ 2, this would contribute less than 0.06 C of the estimated 0.6 C mean global warming between the Maunder Minimum and the middle of last century, before significant anthropogenic contributions could be involved.»

First, how do you reconcile a high climate sensitivity (say 3 - 5 C / doubling) with the fact that there is very low correlation between CO2 and climate in the 500 million time scale?

They state that addition of 3000 Gt C to an atmosphere of 2000 Gt C would lead to warming of 5 degrees C, but I don't believe it unless the climate sensitivity is much higher than today.

Cloud responses are more uncertain and that feeds in to the uncertainty in overall climate sensitivity — but the range in the AR4 models (2.1 to 4.5 deg C for 2xCO2) can't yet be constrained by paleo - climate results which have their own uncertainties.

We show that observed global warming is consistent with knowledge of changing climate forcings, Earth's measured energy imbalance, and the canon - ical estimate of climate sensitivity, i.e., about 3 ◦ C global warming for doubled atmospheric CO2.

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.

C has too high a climate sensitivity and a cutoff on use of fossil fuels.

This gives a range of climate sensitivity that is much larger than the IPCC range (1.5 to 4.5 deg C for a doubling of CO2), and which therefore translates to wider bounds on possible climate projections both at the high end and low end.

Global temperature change is about half that in Antarctica, so this equilibrium global climate sensitivity is 1.5 C (Wm ^ -2) ^ -1, double the fast - feedback (Charney) sensitivity.

OK, AJC and others (climateprediction.net) are claiming there is some possibility of a large climate sensitivity above what is generally accepted by the climate modelling community, 6 degrees C perhaps as opposed to a more standard range of 2.5 C to 4C.

Analysis of the Pliocene (c.f. the Nature geoscience article by Lunt et al) would tend to support total climate sensitivities at or even beyond the high end of the IPCC range (I make that about 4.5 C for a doubling, extrapolating from Lunt's Pliocene warming).

Climate sensitivity with surface properties free to change (but with GHG specified as a forcing, a choice relevant to the twenty - first century) is defined in figure 1, which reveals Antarctic temperature increase of 3 C (Wm ^ -2) ^ -1.

In these experiments the climate sensitivity was 2.7 deg C for a doubling of CO2, the net aerosol forcing from 1940 to 2000 was around -0.7 W / m2 (55 % of the total forcing, -1.27, from 1850 to 2000), and the ocean uptake of heat was well - matched to recent observations.

You confuse the IPCC climate sensitivity range (1.5 - 4.5 C) with the estimates of temperatures in 2100 (1.4 to 5.8 C).

This version of the model had a climate sensitivity was around 4 deg C for a doubling of CO2.

Hegerl et al (2006) for example used comparisons during the pre-industrial of EBM simulations and proxy temperature reconstructions based entirely or partially on tree - ring data to estimate the equilibrium 2xCO2 climate sensitivity, arguing for a substantially lower 5 % -95 % range of 1.5 — 6.2 C than found in several previous studies.

The sensitivity of the climate system to human activity (ie how much fossil C we emit, etc.) can be a bit different — especially in the more distant future trajectory.

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:.

The Kerr (2004) Science «Three Degrees of Consensus» summary (cited in the paper but not online) gives the current range across models for climate sensitivity as 2.5 c to 4.0 c.

New paper finds cloud feedback is strongly positive, projects that climate sensitivity is > 3 degrees C per CO2 doubling.