Sentences with phrase «about climate sensitivity in»

Climate responds to many internal and external factors, and understanding how it varied 1000 years ago informs us about factors that might have operated then (and perhaps about climate sensitivity in general), but little about the current mix of factors.

Tomorrow it's a Yale University - led research group, that just published about climate sensitivity in Science.

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.

That uncertainty is represented in the latest crop of global climate models, which assume a climate sensitivity of anywhere from about 3 to 8 degrees F.

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.

First that CO2 is the main climate driver, second that in calculating climate sensitivity the GHE due to water vapour should be added to that of CO2 as a feed back effect and third that the GHE of water vapour is always positive.As to the last point the feedbacks can not be positive otherwise we wouldn't be here to talk about it.

We show how the maintained consensus about the quantitative estimate of a central scientific concept in the anthropogenic climate - change field — namely, climate sensitivity — operates as an «anchoring device» in «science for policy».

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).

Let me amplify on # 37: here's the other RealClimate link (that James» blog point to) I should have put in my comment about climate sensitivity and how uncertainty in aerosols relates to future climate projection: http://www.realclimate.org/index.php?p=115.

In 1980, Exxon assembled a team of climate modelers who investigated fundamental questions about the climate's sensitivity to the buildup of carbon dioxide in the aiIn 1980, Exxon assembled a team of climate modelers who investigated fundamental questions about the climate's sensitivity to the buildup of carbon dioxide in the aiin the air.

Hi, I don't mean to turn this into yet another sceptic thread, but I've read in another site that there apparently are doubts about current models assuming that climate sensitivity is constant.

The bottom line is that if the radiative forcing of the cosmic - ray flux / climate link is valid, then a sensitivity of Tx2 ~ 1 - 1.5 ° is obtained (and about 2 °C if there is no cosmic ray flux climate link, i.e., still relatively low — this is all explained in the linked paper I sent above: [abstract][pdf]-RRB-.

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.

29 A468 - A476 in which a number of experts were asked questions e.g about the climate sensitivity.

Some global warming «skeptics» argue that the Earth's climate sensitivity is so low that a doubling of atmospheric CO2 will result in a surface temperature change on the order of 1 °C or less, and that therefore global warming is nothing to worry about.

It is important to regard the LGM studies as just one set of points in the cloud yielded by other climate sensitivity estimates, but the LGM has been a frequent target because it was a period for which there is a lot of data from varied sources, climate was significantly different from today, and we have considerable information about the important drivers — like CO2, CH4, ice sheet extent, vegetation changes etc..

One recent study examining the Palaeocene — Eocene Thermal Maximum (about 55 million years ago), during which the planet warmed 5 - 9 °C, found that «At accepted values for the climate sensitivity to a doubling of the atmospheric CO2 concentration, this rise in CO2 can explain only between 1 and 3.5 °C of the warming inferred from proxy records» (Zeebe 2009).

Happy to learn more about the use of sensitivity calculations in climate models, if you can point me to the appropriate link.

Is that a good way of thinking about climate feedbacks in relation to climate sensitivity?..

We show how the maintained consensus about the quantitative estimate of a central scientific concept in the anthropogenic climate - change field — namely, climate sensitivity — operates as an «anchoring device» in «science for policy».

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).

And yet, Simon, you were responding to a set of comments which were about climate sensitivity, for which radiative forcing would be a much more relevant metric — and you responded in a fashion which gave no suggestion that you were changing the topic.

[Response: I suspect another common confusion here: the abrupt glacial climate events (you mention the Younger Dryas, but there's also the Dansgaard - Oeschger events and Heinrich events) are probably not big changes in global mean temperature, and therefore do not need to be forced by any global mean forcing like CO2, nor tell us anything about the climate sensitivity to such a global forcing.

Other ways that the standard or «consensus» calculations bias the climate sensitivity upward also exist and are also not negligible (or at least there is no scientific case that they are negligible), but for now it is sufficient to think about, and try to estimate, the magnitude of the increase in H2O and latent heat flow from surface to upper troposphere.

The addition says many climate models typically look at short term, rapid factors when calculating the Earth's climate sensitivity, which is defined as the average global temperature increase brought about by a doubling of CO2 in the atmosphere.

In a phone chat, he said that arguments about specific levels of climate sensitivity, or specific goals for carbon dioxide concentrations, have little meaning as long as the world is not slowing down from its accelerating path on emissions.

What about the feedbacks that are not normally well represented by ECS and normally fall into the Earth System Climate Sensitivity, stuff like the Arctic Ice cover, which now has trends over decades closer to what was seen on centuries in paleoclimate:

In the interview he mentioned the 11 degrees bit and we chatted for a while about how that was a very long term figure (such a climate sensitivity would require a very long time to come into equilibrium) and how we gave no odds at all of that being the case.

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.

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).

(If there were a bigger seasonal signal in the tropical oceans, I am pretty sure that our uncertainty about climate sensitivity would be a whole lot smaller.)

There were about twenty models used in the IPCC report and all gave different results for climate sensitivity.

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.

In regard to the sensitivity of the earths climate to forcings is it still 3C for 550 ppmv equivilent or 6C as James Hansen has postulated for new boundary conditions he has spoken about?

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.

But there are also periods in the past that were warmer than present, and these also provide valuable hints as to climate sensitivity, though the information we have about such times is not as detailed as what we have about the LGM.

Therefore we urgently need a more accurate reconstruction of climate in the pre-industrial millennium, to get rid of the large historical variance of solar forcing / sensitivity of about 1:9, depending of the chosen reconstruction.

If a doubling of CO2 resulted in a temperature increase of approximately 1 K before any non-Planck feedbacks (before water vapor, etc.), then assuming the same climate sensitivity to the total GHE, removing the whole GHE would result in about a (setting the TOA / tropopause distinction aside, as it is relatively small relative to the 155 W / m2 value) 155/3.7 * 1 K ~ = 42 K. Which is a bit more than 32 or 33 K, though I'm not surprised by the difference.

Your estimates of climate sensitivity come from the IPCC, which assumes that aerosols will continue to provide a very strong cooling effect that offsets about half of the warming from CO2, but you are talking about time frames in which we have stopped burning fossil fuels, so is it appropriate to continue to assume the presence of cooling aerosols at these future times?

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.

Note that «equilibrium» in this thread — up through response 162 — was in terms of climate sensitivity, answering the question about where the «extra heat» comes from.

I would also keep in mind the fact that we are only speaking of the short - term Charney Climate Sensitivity, and the long - term climate sensitivity is presumably going to be about twice that — due to ice sheet loss and thClimate Sensitivity, and the long - term climate sensitivity is presumably going to be about twice that — due to ice sheet loss anSensitivity, and the long - term climate sensitivity is presumably going to be about twice that — due to ice sheet loss and thclimate sensitivity is presumably going to be about twice that — due to ice sheet loss ansensitivity is presumably going to be about twice that — due to ice sheet loss and the like.

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.

PAGE09 and DICE2013 have different models of the climate - economics interface and different assumptions about social values, but they agree on what low climate sensitivity does in relative terms to the social cost of carbon.

Scientists often talk about it in terms of the equilibrium climate sensitivity (ECS), which is the long - term temperature increase that we expect from a permanent doubling of atmospheric CO2.

Scientists often talk about it in terms of the equilibrium climate sensitivity (ECS), which is the