Sentences with phrase «estimate of climate sensitivity at»

It appears that the Hansen Scenario B performed fairly well, with an overestimated trend consistent with its estimate of climate sensitivity at what is now considered to be toward the high end of the likely range (although of course, Hansen continues to estimate climate sensitivity at higher levels than most other observers).

I would also bet that Hansen's estimate of climate sensitivity at 3 degrees Centigrade is too high.

I have discussed the estimates of climate sensitivity at more length in connection to the climateprediction.net results in another post.

Not exact matches

The IPCC wishes to destroy the world economy and starve the world of energy and food at a cost of $ 76 trillion over the next 40 year's (UN estimate), to keep global temps below 2C, when even their wildly pessimistic and disconfirmed projections (formally known as predictions) now suggest that climate sensitivity could be as low as 1.5 C, without spending a dime.

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.

About our estimates of the climate transfer sensitivity to solar variations at 11 years and 22 years, Dr. Benestad makes again a great confusion by misquoting and misunderstanding our paper.

In your sixth last line, you've put the Annan and Hargreaves (A&H) estimate of the lower bound of the 95 % confidence limits for climate sensitivity at 1.9 ºC.

In fact, scientists have long recognized the importance of solar variability as one of the factors governing climate (see the very scholarly review of the subject by Bard and Frank, available here at EPSL or here as pdf) An understanding of solar variability needs to be (and is) taken into account in attribution of climate change of the past century, and in attempts to estimate climate sensitivity from recent climate variations.

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.

«note that what is done with these estimates of climate sensitivity for LGM climate is to use the state of the climate already in place at the LGM — including the ice albedo.»

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.

Using Mg / Ca paleothermometry from the planktonic foraminifera Globigerinoides ruber from the past 500 k.y. at Ocean Drilling Program (ODP) Site 871 in the western Pacific warm pool, we estimate the tropical Pacific climate sensitivity parameter (λ) to be 0.94 — 1.06 °C (W m − 2) − 1, higher than that predicted by model simulations of the Last Glacial Maximum or by models of doubled greenhouse gas concentration forcing.

In your sixth last line, you've put the Annan and Hargreaves (A&H) estimate of the lower bound of the 95 % confidence limits for climate sensitivity at 1.9 ºC.

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 obvious answer (from someone who is indeed receptive to arguments for lower - than - consensus climate sensitivities) is that it was on a par with recent hot years because temperatures at US latitudes of the globe really weren't as much cooler in the 1930s / 1940s (compared to the present) than GISS / Hadley's best estimates (from often sketchy global coverage) suggest.

Your attempt to estimate equilibrium climate sensitivity from the 20th C won't work because a) the forcings are not that well known (so the error in your estimate is large), b) the climate is not in equilibrium — you need to account for the uptake of heat in the ocean at least.

Using Mg / Ca paleothermometry from the planktonic foraminifera Globigerinoides ruber from the past 500 k.y. at Ocean Drilling Program (ODP) Site 871 in the western Pacific warm pool, we estimate the tropical Pacific climate sensitivity parameter (λ) to be 0.94 — 1.06 °C (W m − 2) − 1, higher than that predicted by model simulations of the Last Glacial Maximum or by models of doubled greenhouse gas concentration forcing.

As we discussed at the time, those results were used to conclude that the Earth System Sensitivity (the total response to a doubling of CO2 after the short and long - term feedbacks have kicked in) was around 9ºC — much larger than any previous estimate (which is ~ 4.5 ºC)-- and inferred that the committed climate change with constant concentrations was 3 - 7ºC (again much larger than any other estimate — most are around 0.5 - 1ºC).

Maybe the word «equilibrium» should be omitted from all climate sensitivity estimates, from the shortest term values (TCR) to the longest and most comprehensive (Earth System), since all the different forms of sensitivity estimation seem, in my view, to be looking at somewhat different phenomena and should not necessarily yield the same values.

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.

One earlier comment tangentially alluded to this, but there are a lot of gaps that need to be filled in to say what such a result might mean for attempts at estimating climate sensitivity.

A detailed reanalysis is presented of a «Bayesian» climate parameter study (Forest et al., 2006) that estimates climate sensitivity (ECS) jointly with effective ocean diffusivity and aerosol forcing, using optimal fingerprints to compare multi-decadal observations with simulations by the MIT 2D climate model at varying settings of the three climate parameters.

Is there some simple intuitive explanation of how this pipeline warming is estimated with respect to an equilibrium climate sensitivity at a doubling of CO2 equivalent (thus including methane, ozone, aerosols, CFCs...)?

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?

What I still miss is, for climate sensitivity at 2xCO2 (540 ppm) we're discussing here, how you «jump» from a best estimate of 3 °C to 6 °C.

In essence Tung & Zhou are dining at the denialist's last - chance saloon by invoking a 60 - year natural cycle (their cycle of choice being AMO) resulting in a reduced anthropogenic influence on climate, although they make sure to not directly challenge climate sensitivity by asserting that their findings will impact on assessment of net anthropogenic forcing and leave climate sensitivity estimates unchallenged.

(ppm) Year of Peak Emissions Percent Change in global emissions Global average temperature increase above pre-industrial at equilibrium, using «best estimate» climate sensitivity CO 2 concentration at stabilization (2010 = 388 ppm) CO 2 - eq.

We already looked at how climate skeptics rely on a selective reading of the literature to highlight low estimates of climate sensitivity and use the divergence between climate models and measured temperatures to make conjectural statements about climate models being too sensitive to CO2, without considering other factors that could account for such divergence.

Since we can not do controlled experiments, climate science is an OBSERVATIONAL science we can't put the climate in a beaker, we can only look at past temperatures and past forcings to CONSTRAIN our estimate of sensitivity.

The right - hand panel shows ranges of global average temperature change above pre-industrial, using (i) «best estimate» climate sensitivity of 3 °C (black line in middle of shaded area), (ii) upper bound of likely range of climate sensitivity of 4.5 °C (red line at top of shaded area)(iii) lower bound of likely range of climate sensitivity of 2 °C (blue line at bottom of shaded area).

However, because climate scientists at the time believed a doubling of atmospheric CO2 would cause a larger global heat imbalance than today's estimates, the actual climate sensitivities were approximatly 18 % lower (for example, the «Best» model sensitivity was actually closer to 2.1 °C for doubled CO2).

However, as in the FAR, because climate scientists at the time believed a doubling of atmospheric CO2 would cause a larger global heat imbalance than current estimates, the actual «best estimate» model sensitivity was closer to 2.1 °C for doubled CO2.

Using the IPCC climate sensitivity of 3.2 C, the CO2 level by 2100 would need to double by 2100, from today's 392 to 784 ppmv, to reach this warming (the high side IPCC «scenario and storyline» A2 is at this level, with estimated warming of 3.4 C above the 1980 - 1999 average, or ~ 3.2 C above today's temperature).

(By this I mean could one show a perceptible impact on our planet's future climate at a reasonable cost per degree C global warming averted a) at an estimated 2xCO2 climate sensitivity of 3C or b) at a CS of 1C?)

Assuming the same climate sensitivity, Lindzen's estimate of a 2.5 °C drop for a -30 W / m2 forcing would imply that currently doubling CO2 would warm the planet by only a third of a degree at equilibrium, which is well outside the bounds of IPCC estimates and even very low by most skeptical standards.

If however you're referring to the two - year - long process by which I arrived at the poster, in order to see the pre-1970 oscillations more clearly I detrended HadCRUT3 with an estimate of CO2 - induced global warming, without however committing to any particular climate sensitivity.

-- I believe the estimates of climate sensitivity can be improved to the point of usefulness — we should at least try.

As a result, the climate sensitivity for a doubling of CO2 is estimated to be 0.7 K (with the confidence interval 0.5 K − 1.3 K at 99 % levels).

NOTE 1: It is interesting that the IPCC mimics also think they can successfully ignore the evolving research showing the threshold estimates of climate sensitivities to 2XCO2 are now at more moderate to low levels.

At that point, we either have to hope climate sensitivity is on the very low end of the range that scientists have estimated, or we're busting through the 2 °C limit.

The Lewis and Curry paper said the best estimate for equilibrium climate sensitivity — the change in global mean surface temperature at equilibrium that is caused by a doubling of the atmospheric CO2 concentration — was 1.64 degrees.

As a result, the Cess climate sensitivity parameter should not be interpreted at its face value for estimates of model equilibrium climate sensitivity.

If the Earth's true emission temperature (which occurs somewhere at altitude in the troposphere) is less than the 255 K predicted by theory (assuming an albedo 0.306), then the Planck parameter may well be considerably less than the IPCC's value, in which event on this ground alone climate sensitivity may be well below its central estimate of 3.26 K per CO2 doubling.

I am amazed at how estimates of climate sensitivity keep moving down towards the views of Professor Richard Lindzen.

Your last point, however, about Schwartz revising his estimate of climate sensitivity is not relevant at all to my first posting.

The fact that others have created pdfs from sensitivity estimates and that economists uses these pdfs is not a justification; rather, climate researchers and statisticians need to take a close look at this to see whether this line of reasoning is flawed.

Girma, the equilibrium climate sensitivity (estimated at about 3C per CO2 doubling; or about 0.8 C per W / m ^ 2) is not related to the rate of increase, but to how far the increase goes until the Earth is back in energy balance.

Perhaps The Economist should take a look at the best of the best among climate scientists — notably James Hansen who warns that Equilibrium Climate Sensitivity is at least 3 degrees Celsius and that this estimate is probably conserclimate scientists — notably James Hansen who warns that Equilibrium Climate Sensitivity is at least 3 degrees Celsius and that this estimate is probably conserClimate Sensitivity is at least 3 degrees Celsius and that this estimate is probably conservative.

In the report, they find reasons to dismiss the many studies and varying approaches that arrive at higher climate sensitivity estimates, and fail to discuss the shortcomings of the lower sensitivity studies that they prefer.

If one attributes half of the observed warming (instead of only 7 %) to natural forcing, this would put the 2xCO2 climate sensitivity at 0.8 °C, or very close to the Lindzen and Spencer estimates.