Sentences with phrase «about climate sensitivity with»

However, it's very clear that The Economist does * not * «equate» uncertainty about climate sensitivity with uncertainty about emission levels.

Not exact matches

They used two different climate models, each with a different sensitivity to carbon dioxide, to project California's future under two scenarios: an optimistic one, in which we only double the level of carbon dioxide in the atmosphere — since the 19th century we've already increased it by about a third — and a pessimistic scenario, in which we more than triple CO2.

Isaac Held, a National Oceanic and Atmospheric Administration climate scientist, said he agreed with the researchers about the «the importance of getting the ice - liquid ratio in mixed - phase clouds right,» but he doesn't agree that global climate models generally underestimate climate sensitivity.

When Otto calculated the climate sensitivity from his data, he found it was about 2 °C — with a range of 0.9 to 5 °C — well below the IPCC's best estimate of 3 °C.

The Hansen et al study (2004) on target atmospheric CO2 and climate sensitivity is quite clear on this topic: equilibrium responses would double the GCM - based estimates, with very little to be said about transient effects.

If they would use a more realistic climate transfer sensitivity of 0.11 K / Wm -2, or even somewhat higher (0.12 or 0.13) for the long - term, and use trends instead of smooth curve points, they would end up with solar contributions of 10 % or less for 1950 - 2000 and near 0 % and about 10 % in 1980 - 2000 using the PMOD and ACRIM data, respectively.

On the face of it the range of the IPCC models is centrally within the A&H 90 % range, but visual inspection of Figure 1 suggests that A&H find that there is about a 45 % probability that climate sensitivity is below the lower end of the range quoted by Meehl in August 2004 (Of course the IPCC draft report, which I have not seen, may include models with lower sensitivity than 2.6 ºC).

As for the points Ferdinand makes in his (large) comment, I still contend that Ferdinand is misinterpreting the work on climate sensitivity to various forcings, and the need to make the sensitivity inference consistent with what we know about the physics of the system.

While I'm posting (I can see how you guys get into this) I'm also very uncomfortable with your notion of «tacit knowledge:» it certainly seems to be tacit knowledge in the blogosphere that the chances of the climate sensitivity (equilibrium warming on indefinite stabilization at 560ppm CO2, for the non-enthusiasts) being greater than or equal to 6 degrees are too small to be worth worrying about (meaning down at the level of an asteroid strike).

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.

It is important to realize that the nature of CO2's lead / lag relationship with Antarctica is insightful for our understanding of carbon cycle dynamics and the sequence of events that occur during a deglaciation, but it yields very little information about climate sensitivity.

«The closest match, with a much lower degree of uncertainty than most other studies, suggests climate sensitivity is about 2.4 degrees.»

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).

I don't know about Nature and real climatologists, but I was interested in Efficiently constraining climate sensitivity with paleoclimate simulations.

During the first 3 days of March 2005, balmy downtown Honolulu in Hawaii was buzzing with agile scientists conversing, chatting, announcing, briefing and informing about IPCC assessment reports, climate models, model evaluations, climate sensitivities and feedbacks.

Regardless of what we think about D - O events, I am in complete agreement with Stefan that there is no evidence of any kind at present that the present climate suffers any kind of initial - condition sensitivity that would compromise the value of projections of response of statistical quantities to increases in GHG's.

This gives a climate sensitivity of about 3 degrees for a doubling, consistent with the widely used «Charney sensitivity».

With an honest appraisal of the full uncertainty, also in the forcing, one must come to the conclusion that such a short period is not sufficient to draw conclusions about the climate sensitivity.

I sincerely hope that you are not serious in maintaining the following: The peak warming is linearly proportional to the cumulative carbon emitted It doesn't matter much how rapidly the carbon is emitted The warming you get when you stop emitting carbon is what you are stuck with for the next thousand years The climate recovers only slightly over the next ten thousand years At the mid-range of IPCC climate sensitivity, a trillion tonnes cumulative carbon gives you about 2C global mean warming above the pre-industrial temperature.

Over very long time periods such that the carbon cycle is in equilibrium with the climate, one gets a sensitivity to global temperature of about 20 ppm CO2 / deg C, or 75 ppb CH4 / deg C. On shorter timescales, the sensitivity for CO2 must be less (since there is no time for the deep ocean to come into balance), and variations over the last 1000 years or so (which are less than 10 ppm), indicate that even if Moberg is correct, the maximum sensitivity is around 15 ppm CO2 / deg C. CH4 reacts faster, but even for short term excursions (such as the 8.2 kyr event) has a similar sensitivity.

Duster, you can experiment with CO2 in a chamber until the cows come home and it will never give you a clue about climate sensitivity.

We can study ice ages to approximate climate sensitivity, which indicate a value consistent with the accepted value of about 2 - 4 °C per doubling of CO2.

Surely we can agree about the basics (radiative physics; likelihood that climate sensitivity is above 2C; impacts will likely increase with increased warming).

Steve: Willis, I've posted late in 2007 about Kiehl's report that GCMs with high climate sensitivity adopted aerosol histories with relative low variability and conversely; thus there is more coherence in the GCM ensembles than in the underlying data — suggesting a certain shall - we - say opportunism in the aerosol history selection.

Armour's findings were about time - varying climate sensitivity and have nothing at all to do with forcing efficacies.

The author's points on non-linearity and time delays are actually more relevant to the discussion in other presentations when I talked about whether the climate models that show high future sensitivities to CO2 are consistent with past history, particularly if warming in the surface temperature record is exaggerated by urban biases.

If you've read Lindzen's talk at the House of Commons, you'll have seen where the IPCC completely agrees with his opening remarks about climate sensitivity.

If you want to argue with people about the «accuracy» of global temps, present day and in the past, I think that you should take that up with someone like Judith, who thinks that the records are accurate enough to determine that there has been a trend of rising global SATs that has «paused,» and that the measurements are accurate enough to determine a «wave,» and to determine a range of the climate's sensitivity to ACO2.

Traditionally, only fast feedbacks have been considered (with the other feedbacks either ignored or treated as forcing), which has led to estimates of the climate sensitivity for doubled CO2 concentrations of about 3 ◦ C.

Plugging in our possible climate sensitivity values, this gives us an expected surface temperature change of about 1 — 2.2 °C of global warming, with a most likely value of 1.4 °C.

He paid no attention to my points, made strawman arguments based on putting words in my mouth that I had not said, made blatantly false claims about my climate analyses, failed to distinguish the different notions of climate sensitivity, and misrepresented Arrhenius, Let me illustrate with the following dozen -LRB-!)

[¶]... Basing our assessment on a combination of several independent lines of evidence, as summarised in Box 10.2 Figures 1 and 2, including observed climate change and the strength of known feedbacks simulated in GCMs, we conclude that the global mean equilibrium warming for doubling CO2, or «equilibrium climate sensitivity», is likely to lie in the range 2 °C to 4.5 °C, with a most likely value of about 3 °C.

The frontpage implies that climate science to date has not been «real,» while the many errors made by the speakers as well as their serious credibility issues (Willie Soon's infamous paper, another paper more recently with Noah Robinson that made up data, Spencer's flawed book on climate sensitivity, Singer's history since about 1990, Schmitt's uncorrected error in a NASA paper, Bast and Taylor's lies in defense of Schmitt, and so on) suggest the opposite — the speakers at the ICCC are the ones attempting to falsify the science.

James Annan, of Frontier Research For Global Change, a prominent «warmist», recently said high estimates for climate sensitivity now look «increasingly untenable», with the true figure likely to be about half of the IPCC prediction in its last report in 2007.

The vast majority of the public knows a lot less about climate sensitivity, the link between hurricanes and CO2 or analogues with past climates than either you or I do, but the link between these issues and actual policy is quite convoluted.

Equilibrium climate sensitivity is likely to be in the range 2 °C to 4.5 °C with a most likely value of about 3 °C, based upon multiple observational and modelling constraints.

It could be that an improved understanding of the dynamical transport mechanisms associated with the DALR and convection might help place limits on the climate sensitivity to GH forcing, and that people on this list could be thinking about things like that instead of trying to pretend that the GHE isn't real.

Any student of climate can say with confidence that the IPCC Fourth Assessment was wrong about either attribution or climate sensitivity or both.

Thinking about the problem in terms of temperature increase for a doubling of atmospheric CO2 (which we will probably exceed with current policies and energy trends), even studies that reinforce the skeptical narrative of low mean climate sensitivity leaves some chance of warming greatly exceeding international goals and historical boundaries (say a 5 percent chance of warming exceeding 4 °C).

With «climate» science we have the advocates messaging both the data and the models to get what they believe will happen — e.g. with CO2 sensitivity about twice reality eWith «climate» science we have the advocates messaging both the data and the models to get what they believe will happen — e.g. with CO2 sensitivity about twice reality ewith CO2 sensitivity about twice reality etc..

You could go further and talk about tuning to «emergent constraints» for climate sensitivity, observational metrics that are correlated with climate sensitivity when looking across model ensembles.

Dolphinhead @ 12:36, Richard Betts had a cautious but basically positive comment about Nic Lewis's derivation of climate sensitivity here on the post with Nic's calculations.

The IPCC in its Fourth Assessment Report (AR4) concluded that climate sensitivity is likely to be in the range 2 to 4.5 °C with a best estimate of about 3 °C, and is very unlikely to be less than 1.5 °C.

In most cases, these range from about 2 to 4.5 C per doubled CO2 within the context of our current climate — with a most likely value between 2 and 3 C. On the other hand, chapter 9 describes attempts ranging far back into paleoclimatology to relate forcings to temperature change, sometimes directly (with all the attendant uncertainties), and more often by adjusting model parameters to determine the climate sensitivity ranges that allow the models to best simulate data from the past — e.g., the Last Glacial Maximum (LGM).

The problem catastrophists have with defending their higher climate sensitivities is that these sensitivities imply that we should have seen much more warming over the past 100 years, as much as 1.5 C or more instead of about 0.6 C.

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.

The problem with JA's argument about bounding climate sensitivity is that even with a Cauchy prior, the result depends critically on the location of the prior.

This fits in pretty nicely, in a rough sort of way, with the idea that climate sensitivity is about half what the IPCC thinks, e.g., you might get 1.25 to 1.5 degrees C for a doubling of CO2 and equivalents.

Transient Climate Sensitivity (TCS) is a more realistic way to evaluate the actual global warming effects of CO2 that can be validated with actual data, but TCS is rarely reported in peer - reviewed paper or media articles, because the sensitivity is about half the ECS value and is not sSensitivity (TCS) is a more realistic way to evaluate the actual global warming effects of CO2 that can be validated with actual data, but TCS is rarely reported in peer - reviewed paper or media articles, because the sensitivity is about half the ECS value and is not ssensitivity is about half the ECS value and is not so alarming.

This figure indicates 3 things: (1) the time lag between emitting greenhouse gases and when we see the principle effect is about 30 years, due mostly to the time required to heat the oceans, (2) the rate of temperature increase predicted by a climate sensitivity of 3 °C tracks well with the observed rate of temperature increase, and (3) we have already locked in more than 1.5 °C warming.