Sentences with phrase «sensitivity estimate means»

The latest example comes in an article in today's Times, which claims a new low climate sensitivity estimate means «Climate change could be slower than forecast».

Not exact matches

If you check out the study, you will see that the results of the sensitivity analysis did move some estimates that favored water birth to the null — which means that there was no difference between water birth and conventional delivery.

In a sensitivity analysis, inclusion in the meta - analysis of the assumed zero estimates from the five studies (table 1) with no published mean differences attenuated the overall summary estimate for systolic blood pressure (mean difference: — 1.0 mmHg, 95 percent CI: — 1.6; — 0.4; p = 0.002), but there was still strong evidence of an inverse association.

This new research takes away the lower end of climate sensitivity estimates, meaning that global average temperatures will increase by 3 °C to 5 °C with a doubling of carbon dioxide.»

The NGN article itself gives a good explanation of climate sensitivity and the various studies and estimates of it, and does quote Michael Schlesinger of the University of Illinois saying that Hegerl's result «means climate sensitivity is larger than we thought for 30 years, so the problem is worse than we thought.

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.

Using an estimate of the mean tropical cooling based on geochemical proxies of 2.5 - 3 deg would yield a sensitivity closer to 3.5 deg (but perhaps Julia will comment).

Aldrin et al produce a number of (explicitly Bayesian) estimates, their «main» one with a range of 1.2 ºC to 3.5 ºC (mean 2.0 ºC) which assumes exactly zero indirect aerosol effects, and possibly a more realistic sensitivity test including a small Aerosol Indirect Effect of 1.2 - 4.8 ºC (mean 2.5 ºC).

Here we have shown that the degree to which semicircular canals approach orthogonality is correlated with mean estimated sensitivity to angular accelerations, and that mean sensitivity in turn is solely determined by canal radius of curvature.

It bears noting that even if the SEA mean estimate were correct, it still lies well above the ever - more implausible estimates of those that wish the climate sensitivity were negligible.

Indeed, if one accepts a very liberal risk level of 50 % for mean global warming of 2 °C (the guiderail widely adopted) since the start of the industrial age, then under midrange IPCC climate sensitivity estimates, then we have around 30 years before the risk level is exceeded.

More recently Köhler et al (2010)(KEA), used estimates of all the LGM forcings, and an estimate of the global mean temperature change, to constrain the sensitivity to 1.4 - 5.2 ºC (5 — 95 %), with a mean value of 2.4 ºC.

To further examine whether psychophysiological interactions predicted behavioural performance, we additionally correlated the mean difference in beta estimates of each significant PPI cluster with participants» overall sensitivity in detecting grammatical violations.

The sensitivity measure gives an estimate of the mean area under the ROC curve, and the dissociation of sensitivity and bias avoids a misrepresentation of performance due to conflated hit rates.

Environmetrics http://onlinelibrary.wiley.com/doi/10.1002/env.2140/abstract;jsessionid=38E88DBEDFC0F5214703FE5877A722A3.d03t03?systemMessage=Wiley+Online+Library+will+be+disrupted+17+March+from+10-14+GMT+%2806-10+EDT%29+for+essential+maintenance&userIsAuthenticated=false&deniedAccessCustomisedMessage= [from the Knappenberger piece: «The [climate sensitivity] mean is 2.0 °C... which is lower than the IPCC estimate from the IPCC Fourth Assessment Report (IPCC, 2007), but this estimate increases if an extra forcing component is added, see the following text.

Bottom line, you can't estimate sensitivity from the mean conditions today — you need to look at a climate change.

The NGN article itself gives a good explanation of climate sensitivity and the various studies and estimates of it, and does quote Michael Schlesinger of the University of Illinois saying that Hegerl's result «means climate sensitivity is larger than we thought for 30 years, so the problem is worse than we thought.

«The [climate sensitivity] mean is 2.0 °C... which is lower than the IPCC estimate from the IPCC Fourth Assessment Report (IPCC, 2007), but this estimate increases if an extra forcing component is added, see the following text.

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.»

Using an estimate of the mean tropical cooling based on geochemical proxies of 2.5 - 3 deg would yield a sensitivity closer to 3.5 deg (but perhaps Julia will comment).

Since the sensitivity estimates using the Otto et al method in the model world are biased low, using the estimated efficacies in the real world means that the sensitivities from the adjusted methodologies are going to be increased, and indeed that's exactly what happens.

However, it is important to keep in mind that we might easily more than double it if we really don't make much effort to cut back (I think the current estimated reserves of fossil fuels would increase CO2 by a factor of like 5 or 10, which would mean a warming of roughly 2 - 3 times the climate sensitivity for doubling CO2 [because of the logarithmic dependence of the resulting warming to CO2 levels]-RRB-... and CO2 levels may be able to fall short of doubling if we really make a very strong effort to reduce emissions.

One earlier comment tangentially alluded to this, but there are a lot of gaps that need to be filled in to say what such a result might mean for attempts at estimating climate sensitivity.

The climate sensitivity is closest associated with, for which the mean estimate was 1.11, with a 5 -95-percentile interval of 0.74 - 1.62.

As we only have one instrumental temperature trend, the difference between the two estimates for solar sensitivities means that a larger influence must be compensated by a smaller influence of the GHG / aerosol tandem, to fit the temperature trend in the past century...

The results of the analysis demonstrate that relative to the reference case, projected atmospheric CO2 concentrations are estimated by 2100 to be reduced by 3.29 to 3.68 part per million by volume (ppmv), global mean temperature is estimated to be reduced by 0.0076 to 0.0184 °C, and sea - level rise is projected to be reduced by approximately 0.074 — 0.166 cm, based on a range of climate sensitivities.

To translate this into 2xCO2 temperature impact (equilibrium climate sensitivity) means that this would be around 0.6 deg C including all feedbacks, compared to the Myhre et al. estimate before feedbacks of around 1.0 degC and the IPCC mid-range estimate including all feedbacks of 3.2 degC.

The implications are still that a lower estimate of climate sensitivity means «there is a reason to act».

This means that approaches that use the first order approximation to estimate climate sensitivity from the instrumental period (such as Lewis) will underestimate climate sensitivity and approaches that use the first order to estimate climate sensitivity using paleoclimate data (Hansen and others) will overestimate climate sensitivity.

It means dynamic approaches need to be taken to estimate sensitivity.

(By this I mean could one show a perceptible impact on our planet's future climate at a reasonable cost per degree C global warming averted a) at an estimated 2xCO2 climate sensitivity of 3C or b) at a CS of 1C?)

Recall that my comment was meant to point out that one can estimate a sensitivity of temperature to CO2 without recourse to models.

Because clouds affect sunlight absorbed at the Earth's surface, excluding them means «the range that we estimate for climate sensitivity may be too narrow,» he said.

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.

The Lewis and Curry paper said the best estimate for equilibrium climate sensitivity — the change in global mean surface temperature at equilibrium that is caused by a doubling of the atmospheric CO2 concentration — was 1.64 degrees.

His work would then have meaning within a framework that people accept: «we need to estimate sensitivity»

Does this mean you don't actually believe in these sensitivity estimates?

I again used the variance in our estimate of climate sensitivity as an indicator of uncertainty — if you are unclear about what that means, refresh your memory here.

Similar, less noticeable, events have probably occurred within the last million years or so, meaning that any estimates of «sensitivity» from before that time are highly questionable.

The equilibrium climate sensitivity will be about 50 % greater than this due to the ocean acting as a heat sink, so the ECS will be about 3C, in line with the mean estimate from the models.

For example, the mean estimate for sensitivity is 3C.

Constraining the LGM cooling from proxy data yields a most likely climate sensitivity around 2.5 K, which is lower than ECS estimates based on present - day variability and / or the mean state.

To be precise, it is closest to the mean climate sensitivity estimate from the IPCC AR5, which there is good reason to think lies somewhere between 3 and 3.1 oC.

PS to my 4:48 AM post: The non-linearity of the TCR estimate to aerosol forcing also means that a 0.49 W / m2 total adjustment would bring the TCR estimate down to about 1.4 °C, not 1.26 °C (which was based on a simple scaling of Shindell's sensitivity analysis).

This means that volcanic aerosols have minimal long - term cooling effects and therefore, the warming effect of CO2 has to be much lower than assumed in Hansen's climate models and thus climate sensitivity estimates must be lowered even further.

Their estimates of CO2 sensitivity (the increase in global mean temperature due to a doubling of CO2) are, IMHO, at least four times too big.

Aldrin's use of a uniform prior for ECS will have biased up his mean and 95 % / 97.5 % bound estimates for sensitivity, but probably doesn't make much difference to his aerosol forcing estimates.

Based on the climate sensitivity we have estimated, the amount of greenhouse gases presently in the atmosphere will cause an eventual global mean warming of about 1 °C making the global temperature at least comparable to that of the Altithermal, the warmest period in the past 100,000 years.

It means that the current method of estimating climate sensitivity would return a value greater than 3 C.

That means that if in the past the climate responded stronger to a certain (natural) forcing, this will increase the respective estimate of climate sensitivity (which applies to both natural and anthropogenic forcings).