Sentences with phrase «mean climate sensitivity»

If a dominance of La Nina / ocean variability, is causing a hiatus, does that mean climate sensitivity is lower?

If there was a MWP, that does nt mean that climate sensitivity is greater than 3 C.

It is encouraging that the global mean climate sensitivity parameter for cases involving lower stratospheric O3 changes and that for CO2 changes (viz., doubling) are reasonably similar in Christiansen (1999) while being within about 25 % of a central value in Hansen et al. (1997a).

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.

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).

We've had a few specific actionable proposals, like the Hansen et al. suggestion to shut down (and replace) all US coal - fired plants by 2030; a calculation shows that, even using IPCC's arguably exaggerated mean climate sensitivity of 3.2 C, this proposal would theoretically reduce global warming in 2100 by an imperceptible 0.08 C.

The current batch of models have a mean climate sensitivity of about 3 C to doubled CO2 (and range between 2.5 and 4.0 degrees)(Paris meeting of IPCC, July 2004), i.e an uncertainty of about 30 %.

If a dominance of La Nina / ocean variability, is causing a hiatus, does that mean climate sensitivity is lower?

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 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.

If half of past warming, or about.4 C is due to man, that means climate sensitivity is around 1C, exactly the no - feedback number that climate skeptics have thought it was near for years.

Variations in 20th century trends which do not correlate to c02 are routinely dismissed as either aerosols or heat going into the oceans, when it is very clear these are related to PDO cycles, which means climate sensitivity to c02 must be overstated.

(http://www.skepticalscience.com/Do-critics-of-the-hockey-stick-realise-what-theyre-arguing-for.html) If for some reason, temperatures over the Medieval Warm Period turn out to be warmer than previously thought, this means climate sensitivity is actually greater than 3 °C.

Note: this post has been incorporated into the new rebuttal to the myth «No long tail means climate sensitivity is low», as well as «global warming stopped in [insert date]» and «Trenberth can't account for the lack of warming».

Not exact matches

Its sensitivity to climatic variables means that global climate change is likely to have profound impacts on coffee growing and production.

This sensitivity to climatic variables means that global climate change is likely to have profound impacts on coffee growing and production.

[Drew T. Shindell, Inhomogeneous forcing and transient climate sensitivity] That means climate change with an increase of more than a degree Celsius compared with the last century is very likely already.

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 result is that when water vapour processes are correctly represented, the sensitivity of the climate to a doubling of carbon dioxide — which will occur in the next 50 years — means we can expect a temperature increase of at least 4 °C by 2100.

I don't care about consensus, but for what it's worth: 10 out of 17 means a 59 % consensus that climate sensitivity is likely to be 2C or lower and as such global warming is not dangerous according to UN politically agreed criteria.

The whole CAGW — GHG scare is based on the obvious fallacy of putting the effect before the cause.As a simple (not exact) analogy controlling CO2 levels to control temperature is like trying to lower the temperature of an electric hot plate under a boiling pan of water by capturing and sequestering the steam coming off the top.A corollory to this idea is that the whole idea of a simple climate sensitivity to CO2 is nonsense and the sensitivity equation has no physical meaning unless you already know what the natural controls on energy inputs are already ie the extent of the natural variability.

Does it mean that transient climate response (as expressed by ice sheet or see - ice melting among other events) to GHGs is not so far from equilibrium climate sensitivity?

Even if we could determine a «safe» level of interference in the climate system, the sensitivity of global mean temperature to increasing atmospheric CO2 is known perhaps only to a factor of three or less.

The climate sensitivity classically defined is the response of global mean temperature to a forcing once all the «fast feedbacks» have occurred (atmospheric temperatures, clouds, water vapour, winds, snow, sea ice etc.), but before any of the «slow» feedbacks have kicked in (ice sheets, vegetation, carbon cycle etc.).

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.

We propose that the remarkable quantitative stability of the climate sensitivity range has helped to hold together a variety of different social worlds relating to climate change, by continually translating and adapting the meaning of the «stable» range.

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 displacement of the platform is analogous to global mean temperature, and the stiffness of the spring is analogous to climate sensitivity.

One common measure of climate sensitivity is the amount by which global mean surface temperature would change once the system has settled into a new equilibrium following a doubling of the pre-industrial CO2 concentration.

In other words, if climate sensitivity is toward the low end, 2 K is more dangerous than we currently give it credit for, and arguments for low risk because of low sensitivity are less valid because that means that more ecological changes occur for a given temperature change than currently thought.

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.

Regarding your second comment, in point of fact temperature increase is linear with logarithmically increasing CO2: climate sensitivity, you may recall, measures global mean surface temperature increase per doubling of atmospheric concentration of CO2.

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.

I take it you mean that the Margo data is resulting in underestimates of climate sensitivity?

Abstract:» The sensitivity of global climate with respect to forcing is generally described in terms of the global climate feedback — the global radiative response per degree of global annual mean surface temperature change.

First let's define the «equilibrium climate sensitivity» as the «equilibrium change in global mean surface temperature following a doubling of the atmospheric (equivalent) CO2 concentration.

The most unfortunate thing is that the somewhat clumsy press - release obscured the true message, which is that physics alone does not rule out high sensitivities, even if you impose the requirement that the model match the present annual mean climate.

The climate sensitivity classically defined is the response of global mean temperature to a forcing once all the «fast feedbacks» have occurred (atmospheric temperatures, clouds, water vapour, winds, snow, sea ice etc.), but before any of the «slow» feedbacks have kicked in (ice sheets, vegetation, carbon cycle etc.).

Unfortunately for policymakers and the public, while the basic science pointing to a rising human influence on climate is clear, many of the most important questions will remain surrounded by deep complexity and uncertainty for a long time to come: the pace at which seas will rise, the extent of warming from a certain buildup of greenhouse gases (climate sensitivity), the impact on hurricanes, the particular effects in particular places (what global warming means for Addis Ababa or Atlanta).

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 [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.

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).

At the very least he needs to provide a pointer to «the calculations of the sensitivity of the mean climate to a doubling of CO2 concentration» that he has found are ignoring changes in non-radiative atmospheric heat transport.

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.»

[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.

I am making just another attempt to find a layman's explanation about what climate sensitivity numbers can mean about future world temperatures.

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.

Abstract:» The sensitivity of global climate with respect to forcing is generally described in terms of the global climate feedback — the global radiative response per degree of global annual mean surface temperature change.

Moreover, some have argued that a strong aerosol radiative forcing means that the climate sensitivity has to be -LSB-...]