Sentences with phrase «climate sensitivity based»

In short the PETM seems to contradict the AGW point of equilibrium climate sensitivity based on a new level of forcing through CO2 increase..

So, it's really aerosols that you have to rely on to come up with a low climate sensitivity based on temperature rise to date and present overall forcing (2.4 W / m2 less thermal inertia of 0.75 W / m2 giving 1.65 W / m2 with only 0.7 C warming, while 4 - 5 W / m2 is supposed to give 3C).

Strangelove you wrote: «Incidentally, 1C / (2x CO2) is also the no - feedback climate sensitivity based on theoretical calculations.»

Incidentally, 1 C / (2x CO2) is also the no - feedback climate sensitivity based on theoretical calculations.

Here we briefly discuss the radiative forcing estimates used for understanding climate during the last millennium, the mid-Holocene and the Last Glacial Maximum (LGM)(Section 9.3) and in estimates of climate sensitivity based on palaeoclimatic records (Section 9.6.3).

The relatively slow rate of warming over the past decade has lowered some estimates of climate sensitivity based on surface temperature records.

There is one problem with determining the climate sensitivity based on CO2 feedback forcing.

While climate contrarians like Richard Lindzen tend to treat the uncertainties associated with clouds and aerosols incorrectly, as we noted in that post, they are correct that these uncertainties preclude a precise estimate of climate sensitivity based solely on recent temperature changes and model simulations of those changes.

However, as Hansen notes, empirical estimates of climate sensitivity based on paleoclimate data are consistent with the sensitivity in climate models of approximately 3 °C for doubled atmospheric CO2.

Therefore, estimating equilibrium climate sensitivity based on measurements of a climate that's out of equilibrium requires making some significant assumptions, for example that feedbacks will remain constant over time.

Bayesian estimation of climate sensitivity based on a simple climate model fitted to observations of hemispheric temperature and global ocean heat content.

Also, FYI, there is an update to the estimated climate sensitivity based on observations in Murphy et al. (JGR, 114, D17107, doi: 10.1029 / 2009JD012105, 2009).

Think about it — if the various estimates of climate sensitivity based on the instrumental period still had such fat tails just five years ago, then why would an extra five years suddenly turn that around and allow calculations of sensitivity based on the instrumental period to now rule out high sensitivities?

I think that any assessment of climate sensitivity based on the short term temperatures record is fraught with major difficulties and the implied assumptions do not stand up.

As we discussed regarding the Norwegian paper, studies estimating climate sensitivity based on recent data may be biased low due to a failure to account for increased heat transfer to the 700 — 2000 meter ocean layer (Figure 3).

Instead, the actual climate sensitivity based on empirical measurements is approximately 0.7 °C per doubling of CO2 levels, which will not lead to any of the claimed climate disruption and / or weather disasters that alarmists rely on to frighten policymakers.

«Lewis & Crok perform their own evaluation of climate sensitivity, placing more weight on studies using «observational data» than estimates of climate sensitivity based on climate model analysis.»

6, No. 6 (June 2013), pp. 415 — 416; Magne Aldrin et al., «Bayesian Estimation of Climate Sensitivity Based on a Simple Climate Model Fitted to Observations of Hemispheric Temperatures and Global Ocean Heat Content,» Environmetrics, Vol.

[12] Magne Aldrin et al., «Bayesian Estimation of Climate Sensitivity Based on a Simple Climate Model Fitted to Observations of Hemispheric Temperatures and Global Ocean Heat Content,» Environmetrics, Vol.

If the decade plus between 1998 and 2008 isn't long enough to disprove a significant climate sensitivity, then how long do you think it would take to actually demonstrate or infer a value of climate sensitivity based on measured temperatures.

And then there's the even higher Earth System Climate Sensitivity based on slower feedbacks, hovering around 6 °C / doubling, for a rise of 24 °C with four doublings.

Bayesian estimation of climate sensitivity based on a simple climate model fitted to observations of hemispheric temperatures and global ocean heat content

One of his reasons to claim that «the risk of catastrophic anthropogenic global warming appears to be so low that it is not currently worth doing anything to try to control it» is that he uses a very low value for the climate sensitivity based on non-reviewed «studies», while ignoring the peer - reviewed work.

Bayesian estimation of climate sensitivity based on a simple climate model fitted to observations oh hemispheric temperature and global ocean heat content.

What evidence is there for the assumption that climate sensitivity based on paleo record is applicable to present day?

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.

One of his reasons to claim that «the risk of catastrophic anthropogenic global warming appears to be so low that it is not currently worth doing anything to try to control it» is that he uses a very low value for the climate sensitivity based on non-reviewed «studies», while ignoring the peer - reviewed work.

Climate scientists have also attempted to estimate climate sensitivity based on the response to recent large volcanic eruptions, such as Mount Pinatubo in 1991.

From the article: «The most likely value of equilibrium climate sensitivity based on the energy budget of the most recent decade is 2.0 °C, with a 5 — 95 % confidence interval of 1.2 — 3.9 °C»

Not exact matches

The conclusion that limiting CO2 below 450 ppm will prevent warming beyond two degrees C is based on a conservative definition of climate sensitivity that considers only the so - called fast feedbacks in the climate system, such as changes in clouds, water vapor and melting sea ice.

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.

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.

You can always count on the weather... to ruin a perfectly good game === Dr Norman Page says: September 14, 2013 at 8:12 am This new sensitivity estimate is merely a minimum tweak to a hopelessly faulty process.The climate models are incorrectly structured because they are based on three irrational and false assumptions.

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.

«Based on the satellite data gathered, we can identify areas that, over the past 14 years, have shown high sensitivity to climate variability,» says researcher Alistair Seddon at the Department of Biology at the University of Bergen (UiB).

The data is only 33 years in length, but based on that data, there is no first order correlation between temperature and CO2 during its 33 year period and this suggests that then signal to CO2 (ie., Climate Sensitivity) is so low that it can not be measured within the sensitivity, resolution and errors of our best current temperature meSensitivity) is so low that it can not be measured within the sensitivity, resolution and errors of our best current temperature mesensitivity, resolution and errors of our best current temperature measurements.

Therefore studies based on observed warming have underestimated climate sensitivity as they did not account for the greater response to aerosol forcing, and multiple lines of evidence are now consistent in showing that climate sensitivity is in fact very unlikely to be at the low end of the range in recent estimates.

The «equilibrium» sensitivity of the global surface temperature to solar irradiance variations, which is calculated simply by dividing the absolute temperature on the earth's surface (288K) by the solar constant (1365Wm - 2), is based on the assumption that the climate response is linear in the whole temperature band starting at the zero point.

From the paper...» These results provide enhanced confidence in the range of climate sensitivity in climate simulations, which are based on a positive uppertropospheric water vapor feedback.

The calculations of prospective warming in the OXONIA lecture and the accompanying discussion papers are based on the new climate sensitivity estimates by Murphy et al which were published in Nature, 12 August 2004, vol.

I agree (as does IPCC) that there is uncertainty, as stated, in the climate sensitivity, but you are completely unjustified in your claim that the cosmic - ray correlation (for which there is still no sound physical basis or quantified mechanism) supports the lower end of the sensitivity range.

This changing climate sensitivity may be the result of other environmental factors that have, since the 1950s, increasingly acted to reduce tree - ring density below the level expected on the basis of summer temperature changes.

A 2008 study led by James Hansen found that climate sensitivity to «fast feedback processes» is 3 °C, but when accounting for longer - term feedbacks (such as ice sheet disintegration, vegetation migration, and greenhouse gas release from soils, tundra or ocean), if atmospheric CO2 remains at the doubled level, the sensitivity increases to 6 °C based on paleoclimatic (historical climate) data.

Most of the non-model estimates of climate sensitivity are based on the analyses using other forcings such as solar and aerosols, and the assumption that sensitivity to CO2 will be the same, despite the differences in way these forcings couple to the climate system.

Using these much smaller, observationally based climate sensitivities, the projected warming from continued use of fossil fuels will be moderate and benign for the foreseeable future.

So the reference system climate sensitivity parameter is based on a negative feedback due to Stefan's law.

I think that some comment on my energy balance based climate sensitivity estimate of 1.6 - 1.7 °C (details at http://www.webcitation.org/6DNLRIeJH), which underpinned Matt Ridley's WSJ op - ed, would have been relevant and of interest.

Given that clouds are known to be the primary source of uncertainty in climate sensitivity, how much confidence can you place in a study based on a model that doesn't even attempt to simulate clouds?

A combination of circumstances makes model - based sensitivity estimates of distant times and different climates hard to do, but at least we are getting a good education about it.

The risk assessment must be based on every tipping point being breached, so for all intents and purposes, climate sensitivity is unconstrained.