Sentences with phrase «sensitivity than estimated»

The absolute truth will not be known for a century, if ever, but we may get some good indications if the coming decades see stabilization of temperatures despite what seems inevitable CO2 increases, which will argue for a much lower level of CO2 sensitivity than estimated by the official climate Team.

This implies a greater value of climate sensitivity than estimated in the 2006 paper.

Not exact matches

Since changes in interest rates impact bond funds differently than bonds and CDs, estimates of price sensitivity may be less accurate the larger the shift in interest rates.

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.

From at least Lorius et al (1991)-- when we first had reasonable estimates of the greenhouse gases from the ice cores, to an upcoming paper by Schneider von Deimling et al, where they test a multi-model ensemble (1000 members) against LGM data to conclude that models with sensitivities greater than about 4.3 ºC can't match the data.

About the transfer sensitivity to 22 years, Z22y = 0.17 + / -0.06 K / W / m ^ 2, we have clearly explained in our paper that this is approximately 1.5 times larger than Z11y and this is in agreement with theoretical energy balance model estimates such as Wigley (1988) or Foukal et al (2004).

In this commentary, I will discuss the question «If somebody were to discover that climate variations in the past were stronger than previously thought, what would be the implications for estimates of climate sensitivity?»

Note that the old GISS model had a climate sensitivity that was a little higher (4.2 ºC for a doubling of CO2) than the best estimate (~ 3ºC) and as stated in previous years, the actual forcings that occurred are not the same as those used in the different scenarios.

Only a few estimates account for uncertainty in forcings other than from aerosols (e.g., Gregory et al., 2002a; Knutti et al., 2002, 2003); some other studies perform some sensitivity testing to assess the effect of forcing uncertainty not accounted for, for example, in natural forcing (e.g., Forest et al., 2006; see Table 9.1 for an overview).

Using Mg / Ca paleothermometry from the planktonic foraminifera Globigerinoides ruber from the past 500 k.y. at Ocean Drilling Program (ODP) Site 871 in the western Pacific warm pool, we estimate the tropical Pacific climate sensitivity parameter (λ) to be 0.94 — 1.06 °C (W m − 2) − 1, higher than that predicted by model simulations of the Last Glacial Maximum or by models of doubled greenhouse gas concentration forcing.

You may not be able to «prove» such an honest estimate, but it is more likely to be correct than a value based on some estimate of short term climate sensitivity.

collectively explore reasonable bounds on estimates of climate sensitivities (TCR, ECS), i.e., what we might call extreme sensitivities in the sense that they are «more than likely» not to be exceeded.

Forest et al. (2006) demonstrate that the inclusion of natural forcing affects the estimated PDF of climate sensitivity since net negative natural forcing in the second half of the 20th century favours higher sensitivities than earlier results that disregarded natural forcing (Forest et al., 2002; see Figure 9.20), particularly if the same ocean warming estimates were used.

According to Dr. Alessio Fasano, director for Celiac Research and the chief of pediatric gastroenterology and nutrition at Massachusetts General Hospital, gluten sensitivity may be far more prevalent than previously suspected.13 He estimates virtually all of us are affected to some degree, because we all create something called zonulin in the intestine in response to gluten.

Today, an estimated 3 million Americans have Celiac disease, and gluten sensitivity — thought to be on the rise due to GMO consumption — affects more than 18 million people.

There has been an unusual surge of interest in the climate sensitivity based on the last decade's worth of temperature measurements, and a lengthy story in the Economist tries to argue that the climate sensitivity may be lower than previously estimated.

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.

(in general, whether for future projections or historical reconstructions or estimates of climate sensitivity, I tend to be sympathetic to arguments of more rather than less uncertainty because I feel like in general, models and statistical approaches are not exhaustive and it is «plausible» that additional factors could lead to either higher or lower estimates than seen with a single approach.

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.»

The obvious answer (from someone who is indeed receptive to arguments for lower - than - consensus climate sensitivities) is that it was on a par with recent hot years because temperatures at US latitudes of the globe really weren't as much cooler in the 1930s / 1940s (compared to the present) than GISS / Hadley's best estimates (from often sketchy global coverage) suggest.

Using Mg / Ca paleothermometry from the planktonic foraminifera Globigerinoides ruber from the past 500 k.y. at Ocean Drilling Program (ODP) Site 871 in the western Pacific warm pool, we estimate the tropical Pacific climate sensitivity parameter (λ) to be 0.94 — 1.06 °C (W m − 2) − 1, higher than that predicted by model simulations of the Last Glacial Maximum or by models of doubled greenhouse gas concentration forcing.

This figure is of more relevance to risk management than raw climate sensitivity estimates (essential though they are for doing the calculations).

As stated last year, the Scenario B in that paper is running a little high compared with the actual forcings growth (by about 10 %)(and high compared to A1B), and the old GISS model had a climate sensitivity that was a little higher (4.2 ºC for a doubling of CO2) than the best estimate (~ 3ºC).

David's comments reminded me of something that Suki Manabe and I wrote more than 25 years ago in a paper that used CLIMAP data in a comparative evaluation of two versions of the 1980s - vintage GFDL model: «Until this disparity in the estimates of LGM paleoclimate is resolved, it is difficult to use data from the LGM to evaluate differences in low latitude sensitivity between climate models.»

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.

This is enough to matter, but it's no more scary than the uncertainty in cloud feedbacks for example, and whether they could put us on the high end of typical climate sensitivity estimates.

In particular, Annan and Hargreaves (2006) used a Bayesian statistical approach that combines information from both 20th century observations and from last glacial maximum data to produce an estimate of climate sensitivity that is much better constrained than by either set of observations alone (see our post on this, here).

As we discussed at the time, those results were used to conclude that the Earth System Sensitivity (the total response to a doubling of CO2 after the short and long - term feedbacks have kicked in) was around 9ºC — much larger than any previous estimate (which is ~ 4.5 ºC)-- and inferred that the committed climate change with constant concentrations was 3 - 7ºC (again much larger than any other estimate — most are around 0.5 - 1ºC).

The IPCC range, on the other hand, encompasses the overall uncertainty across a very large number of studies, using different methods all with their own potential biases and problems (e.g., resulting from biases in proxy data used as constraints on past temperature changes, etc.) There is a number of single studies on climate sensitivity that have statistical uncertainties as small as Cox et al., yet different best estimates — some higher than the classic 3 °C, some lower.

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.

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

As the comment from Covey et al makes clear, he is calculating a sensitivity to surface energy fluxes that is almost 100x larger than standard estimates of the climate sensitivity.

In this commentary, I will discuss the question «If somebody were to discover that climate variations in the past were stronger than previously thought, what would be the implications for estimates of climate sensitivity?»

What's new is that several recent papers have offered best estimates for climate sensitivity that are below four degrees Fahrenheit, rather than the previous best estimate of just above five degrees, and they have also suggested that the highest estimates are pretty implausible.

If they were, wouldn't there be trends in, for example, sensitivity estimates increasing over time rather than staying fairly stable?

Could some aspect of our situation, e.g. the extreme rapidity of the forcing change, be sufficiently novel to make Earth's climate respond differently than it has in the past, and could this cause divergence from models based on paleoclimate sensitivity estimates?

They do cite a study by Lindzen and Choi, which has shown, based on ERBE satellite observations, that the net impact of a doubling of CO2 including all feedbacks is likely to be significantly lower than the model - based estimates by Myhre for sensitivity without feedbacks.

Here is another interesting comment: https://judithcurry.com/2012/06/25/questioning-the-forest-et-al-2006-sensitivity-study/#comment-212952 This gives information on other work that suggests climate sensitivity may be significantly lower than the IPCC AR4 consensus estimate.

So the two estimates (with and without solar forcing) give me a range of 0.7 C to 1.4 C for the 2xCO2 climate sensitivity, based on actually observed CO2 and temperature records, rather than model simulations and assumptions.

Correcting for this factor alone would more than double his «climate sensitivity» estimate.

Rather than engaging in endlessly nitpicking, unproductive arguments over unknowns such as the logarithmic exponent describing the almost nonexistent / nonexistent effect of carbon dioxide on temperature, and the «estimate» of CO2 sensitivity, let's look at empirical evidence, and the big picture: CO2 is rising, and the planet's temperature is falling.

Kenneth, I really think it is all about reducing the credibility of any empirical estimate which yields other than high sensitivity.

Is there any indication of acknowledgement climate sensitivity may be closer to the Forster / Gregory06 estimate (not the IPCC replot) than the IPCC AR4 concluded?

Anyone reading our paper may or may not agree with our choice of parameters and hence with our revised estimates of climate sensitivity, which are very much lower and very much closer to observed reality than those of the more complex models.

Another example would be someone who insists on ignoring forcing from GHG's other than CO2 when they estimating climate sensitivity; again, quite disconnected from reality.

Notice, for instance, that one account of the consensus (more accurate than Grimes's) holds that «most of the warming in the second half of the twentieth century has been caused by man», and does not exclude the majority of climate sceptics, who typically argue that the IPCC over estimates climate sensitivity.

Using models that don't do what you need to say sensitivity is even higher than models estimate, so that warmunists can ignore all the observational effective sensitivity estimates, smacks of illogical desperation.

An updated estimate of the equilibrium climate sensitivity distribution (ECS)-- a measure of CO2's temperature impact — reduces the 2020 estimate of SCC by more than 40 percent; and