Sentences with phrase «more on climate sensitivity»

more on climate sensitivity here: http://www.ukweatherworld.co.uk/forum/forums/thread-view.asp?tid=25003&start=1

For more on climate sensitivity, you can read this pdf.

Not exact matches

When the scientists compared the output of climate models with a decade of satellite measurements of relative humidity, they found that the models that best reproduced observed conditions were built on the premise that climate sensitivity is relatively high — 7 degrees F or more.

The group hopes other scientists will conduct similar experiments using different models to help hone in on a more reliable measure of climate sensitivity.

Based on past observations, Held, who was not involved with the study, said the climate sensitivity of 5 °C or more shown by the new research may be implausible.

«My view on this is that the research needs to broaden out to have more of a focus on variability more generally so that a) we can predict the next few years better b) we can refine our estimates of the sensitivity of the climate system to increases in greenhouse gas concentrations.»

The metric they have developed, the Vegetation Sensitivity Index (VSI), allows a more quantifiable response to climate change challenges and how sensitive different ecosystems are to short - term climate anomalies; e.g. a warmer June than on average, a cold December, a cloudy September, etc..

Note that the last remark can go either way, as the solar signal can even be more enhanced at the cost of the sensitivity for the greenhouse signal... And from Hansen ea.: «Solar irradiance change has a strong spectral dependence [Lean, 2000], and resulting climate changes may include indirect effects of induced ozone change [RFCR; Haigh, 1999; Shindell et al., 1999a] and conceivably even cosmic ray effects on clouds [Dickinson, 1975].

Each and every scientist you've heard on Radio Ecoshock this fall has brought out another feed - back, a greater climate sensitivity, more reasons why we have to cut carbon emission drastically, ideally starting 20 years ago.

They find a climate feedback parameter of 2.3 ± 1.4 W m — 2 °C — 1, which corresponds to a 5 to 95 % ECS range of 1.0 °C to 4.1 °C if using a prior distribution that puts more emphasis on lower sensitivities as discussed above, and a wider range if the prior distribution is reformulated so that it is uniform in sensitivity (Table 9.3).

To get in the mood, there have many climate sensitivity pieces on RC over the years, the most relevant are On Sensitivity: Part I and Part II, and more recently Climate response estimates from Lewis and Curry and a useful counterpoint from Drew Shclimate sensitivity pieces on RC over the years, the most relevant are On Sensitivity: Part I and Part II, and more recently Climate response estimates from Lewis and Curry and a useful counterpoint from Dresensitivity pieces on RC over the years, the most relevant are On Sensitivity: Part I and Part II, and more recently Climate response estimates from Lewis and Curry and a useful counterpoint from Drew Shindelon RC over the years, the most relevant are On Sensitivity: Part I and Part II, and more recently Climate response estimates from Lewis and Curry and a useful counterpoint from Drew ShindelOn Sensitivity: Part I and Part II, and more recently Climate response estimates from Lewis and Curry and a useful counterpoint from DreSensitivity: Part I and Part II, and more recently Climate response estimates from Lewis and Curry and a useful counterpoint from Drew ShClimate response estimates from Lewis and Curry and a useful counterpoint from Drew Shindell.

Pinning a number on how much global temperature rises in response to a doubling of carbon dioxide — known as the climate sensitivity — is a big question in climate science as it helps more accurately predict how much warming we'll see in future.

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.

Now, forgetting entirely the more complex issue of «climate sensitivity» and focusing only on how tiny, minute concentrations of CO2 can make a difference to global temps — one of the oft - repeated and simplistic denialist memes — is there a simple desktop experiment to demonstrate how that can work?

A few things are unequivocal, perhaps (doubling from the present concentration of CO2 will take 140 years [give or take]; the idea that the changes in climate since 1880 have been in the aggregate beneficial; it takes more energy to vaporize a kg of water than to raise its temperature by 1K; ignoring the energy cost of water and latent heat transport [in the hydrologic cycle] leads to equilibrium calculations overestimating the climate sensitivity), but most are propositions that I think need more research, but can't be refuted on present evidence.

More on the lines of a total climate sensitivity of 4.0 degrees.

Model results don't depend critically on resolution — the climate sensitivity of the models is not a function of this in any obvious way, and the patterns of warming seen in coarse resolution models from the 1980s are very similar to those from AR4 or the upcoming AR5 (~ 50 times more horizontal grid points).

My experience is that most groups do not «precisely» tune their models to 20th Century trends or climate sensitivity, but given this example and the Hourdin results, more clarity on exactly what is done (whether explicitly or implicitly) is needed.

On a more serious note, the problem for journalists (if they know what they are doing) in reporting a range of results for climate sensitivity is that the low end is ho - hum, but the higher end is more interesting.

Rather than saying that Judith is wrong, it would be more accurate to say that you disagree with Judith and for that matter Nic Lewis on the scientific validity of AOGCM's for predicting climate patterns or for that matter climate sensitivity.

In # 78 Chris wrote:... «But with every year that the global temperature fails to break new ground (say +0.50 on the Hadley measure) the more receptive I will be to arguments for lower - than - consensus climate sensitivities».

Based on many studies covering a wide range of regions and crops, negative impacts of climate change on crop yields have been more common than positive impacts (high confidence)... Since AR4, several periods of rapid food and cereal price increases following climate extremes in key producing regions indicate a sensitivity of current markets to climate extremes among other factors (medium confidence).

It is my understanding that the uncertainties regarding climate sensitivity to a nominal 2XCO2 forcing is primarily a function of the uncertainties in (1) future atmospheric aerosol concentrations; both sulfate - type (cooling) and black carbon - type (warming), (2) feedbacks associated with aerosol effects on the properties of clouds (e.g. will cloud droplets become more reflective?)

As interesting as how the media latched on to the 11 K climate sensitivity in Stainforth et al. is their total lack of interest in a much more robust (but equally frightening) result.

The differences among proxy reconstructions are still an obstacle when attempting to constrain climate sensitivity more tightly solely on the basis of LGM climate.

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.

Interestingly, our results are actually pretty consistent with a lot of the recent literature on sensitivity: All studies comparing simple models with recent climate change (from Andronova and Schlesinger, 2001, onwards) find high sensitivities (more than 8K, say) are consistent (at the few - percent level) with the observed record unless they are ruled out a priori.

That is a more complex matter as it will depend on the elusive value of climate sensitivity.

Given the last 30 years there is no reason to believe, from a policy perspective, that spending more money on climate change will lead to any more certainty about climate sensitivity.

In terms of advocacy, this is tricky; people in the fossil fuel sector will doubtless claim that lower climate sensitivity means rapid reductions in fossil fuel use are not necessary, so they can go on with their plans for more gas and oil development without breaching the Paris Agreements, etc..

Now, forgetting entirely the more complex issue of «climate sensitivity» and focusing only on how tiny, minute concentrations of CO2 can make a difference to global temps — one of the oft - repeated and simplistic denialist memes — is there a simple desktop experiment to demonstrate how that can work?

Given that our best bet of climate sensitivity has remained the same (1.5 — 4.5 C) for over 30 years with all new information «pretty much cancelling out», at one point do we begin to focus this investment more on mitigation or another approaches to climate change in general?

Unfortunately, there are many factors that preclude an effective bound on the risks — ranging from uncertainties in downscaling to more fundamental issues such as the uncertainty of climate sensitivity.

I agree with her that there is plenty to debate, both on the science in tough areas like attribution and climate sensitivity and on what mix of incentives, investments, policies, communication efforts and other actions can build a more durable human relationship with the climate system.

«Climate sensitivity» remains a subject of intense investigation, and what counts as hellish is a matter of judgment, but United Nations climate negotiators have settled on a goal to limit atmospheric carbon dioxide to 450 parts per million, which would cause the global mean temperature to peak no more than 3.6 °F above preindustrial Climate sensitivity» remains a subject of intense investigation, and what counts as hellish is a matter of judgment, but United Nations climate negotiators have settled on a goal to limit atmospheric carbon dioxide to 450 parts per million, which would cause the global mean temperature to peak no more than 3.6 °F above preindustrial climate negotiators have settled on a goal to limit atmospheric carbon dioxide to 450 parts per million, which would cause the global mean temperature to peak no more than 3.6 °F above preindustrial levels.

More complex metrics have also been developed based on multiple observables in present day climate, and have been shown to have the potential to narrow the uncertainty in climate sensitivity across a given model ensemble (Murphy et al., 2004; Piani et al., 2005).

Read more «Constraints on Climate Sensitivity From Space - Based Measurements of Low - Cloud Reflection»»

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.

Huybers (2010) went on to say: «More recently reported values of climate sensitivity have not deviated substantially.

I have concentrated on the Bayesian inference involved in such studies, since they seem to me in many cases to use inappropriate prior distributions that heavily fatten the upper tail of the estimated PDF for S. I may write a future post concerning that issue, but in this post I want to deal with more basic statistical issues arising in what is, probably, the most important of the Bayesian studies whose PDFs for climate sensitivity were featured in AR4.

On the question of hurricanes, the theoretical arguments that more energy and water vapor in the atmosphere should lead to stronger storms are really sound (after all, storm intensity increases going from pole toward equator), but determining precisely how human influences (so including GHGs [greenhouse gases] and aerosols, and land cover change) should be changing hurricanes in a system where there are natural external (solar and volcanoes) and internal (e.g., ENSO, NAO [El Nino - Southern Oscillation, North Atlantic Oscillation]-RRB- influences is quite problematic — our climate models are just not good enough yet to carry out the types of sensitivity tests that have been done using limited area hurricane models run for relatively short times.

In order to calculate further, the ppm's of CO2 increase in the atmosphere is brought into the game and they simply invent the «climate sensitivity» of 380 ppm of more CO2 (doubling 2000) «is» equal to 3.7 W / sqm on the Earth's surface.

It simply raises serious doubts concerning CAGW based on high climate sensitivity (as outlined by IPCC in its AR4 and, more recently, AR5 reports).

Your comments demonstrate you haven't even the most basic understanding of either economics, electricity systems, electricity generation costing methods or energy more generally, I'd suggest you spend some time trying to get some background to these issues before wasting more time on climate sensitivity.

The discussion of climate sensitivity in the recently released Fifth Assessment Review of the Intergovernmental Panel on Climate Change (IPCC) sheds more light on this parameter, which turns out not to be known with cerclimate sensitivity in the recently released Fifth Assessment Review of the Intergovernmental Panel on Climate Change (IPCC) sheds more light on this parameter, which turns out not to be known with cerClimate Change (IPCC) sheds more light on this parameter, which turns out not to be known with certainty.

Chance that increased GHGs are expected to lead to warming on the scale of the observed warming: this requires estimates of climate sensitivity, ocean heat uptake, etc., but I would think that basic theory suggests that increased GHGs could be responsible for much more than the observed warming.

If the recent papers on climate sensitivity are correct, the KXL maximum theoretical contribution to global warming is even more miniscule.

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.

For a method for that, may I encourage you to look at Roy Spencer's recent model on thermal diffusion in the ocean: More Evidence that Global Warming is a False Alarm: A Model Simulation of the last 40 Years of Deep Ocean Warming June 25th, 2011 See especially his Figure Forcing Feedback Diffusion Model Explains Weak Warming in 0 - 700 m layer as Consistent with Low Climate Sensitivity His model appears to be more accurate than the IPCMore Evidence that Global Warming is a False Alarm: A Model Simulation of the last 40 Years of Deep Ocean Warming June 25th, 2011 See especially his Figure Forcing Feedback Diffusion Model Explains Weak Warming in 0 - 700 m layer as Consistent with Low Climate Sensitivity His model appears to be more accurate than the IPCmore accurate than the IPCC's.