Sentences with phrase «for higher climate sensitivity»

Finally, there is no good reason to widen the range, even though some studies have pointed to the possibility of higher climate sensitivity — but as we have discussed here, they did not provide positive evidence for a higher climate sensitivity, they merely showed that the data constraints used were weak.

With the models being the main «evidence» for high climate sensitivities and a net positive feedback to CO2 forcing, they do not need yet another correlated diagnostic failure.

It seems clear that temperature increases seen so far do not provide any evidence for a high climate sensitivity.

Not exact matches

«If the true climate sensitivity really is as high as 5 degrees C -LSB-(9 degrees F)-RSB-, the only way our descendants will find that out is if they stubbornly hold greenhouse gas concentrations constant for centuries at our target stabilization level.»

«Thus it appears that the Pinatubo cooling favours high climate sensitivity,» say Hansen and his colleagues in a study for a forthcoming issue of the journal National Geographic Research and Exploration.

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.

-- Climate probably has a higher sensitivity for solar than for CO2, for the same change in forcing.

Just for the sake of illustration, though, here's one scenario where higher Holocene variability could go along with lower climate sensitivity: Suppose that some unknown stabilizing mechanism makes the real world less sensitive to radiative forcing than our current models.

Thus it is very important to know what the real impact of historical solar changes is, as 0.1 K in the past, results in climate sensitivity for anthropogenic at the high end, while 0.9 K results in a very low effect of anthropogenic, if the instrumental temperature trend of the last 1.5 century is used as reference.

Note that 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) and as stated in previous years, the actual forcings that occurred are not the same as those used in the different scenarios.

Hansen's model assumed a rather high climate sensitivity of 4.2 °C for a doubling of CO2.

For example, we know the past CO2 radiative forcing to very high accuracy, but there are more uncertainties in the aerosol forcing; applying a consistent climate sensitivity to both CO2 and aerosols, you can get a match to the observed record for a range of different supposed aerosol forcings, but you can't take it too fFor example, we know the past CO2 radiative forcing to very high accuracy, but there are more uncertainties in the aerosol forcing; applying a consistent climate sensitivity to both CO2 and aerosols, you can get a match to the observed record for a range of different supposed aerosol forcings, but you can't take it too ffor a range of different supposed aerosol forcings, but you can't take it too far.

Rather, their analysis shows that if you compare the LGM land cooling with the model land cooling, then the model that fits the land best has much higher GLOBAL climate sensitivity than you get for best fit if you use ocean data.

It seems to me we should use the higher values for climate sensitivity, including the slower feedbacks, for a complete assessment of risks upto the seventh generation, so to speak.

«We indicated 23 years ago — in our 1994 Nature article — that climate models had the atmosphere's sensitivity to CO2 much too high,» said Christy, the lead author in the study, which has been accepted for publication in the 2017 fourth quarter edition of the Asia - Pacific Journal of Atmospheric Sciences and is available online.

(in general, whether for future projections or historical reconstructions or estimates of climate sensitivity, I tend to be sympathetic to arguments of more rather than less uncertainty because I feel like in general, models and statistical approaches are not exhaustive and it is «plausible» that additional factors could lead to either higher or lower estimates than seen with a single approach.

Given the number of ways that things can go wrong with continued CO2 emissions (from ocean acidfication and sea level rise to simple warming, shifting precipitation patterns, release of buried carbon in perma - frost, and the possibility of higher climate sensitivities — which seem to be needed to account for glacial / inter-glacial transitions), crossing our fingers and carrying on with BAU seems nothing short of crazy to me.

The need for prompt (urgent) action implied by these realities may not be a surprise to the relevant scientific community, because paleoclimate data revealed high climate sensitivity and the dominance of amplifying feedbacks.

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.

The possibility of there existing a plausible model with such a high sensitivity is of such overarching importance, I would have liked to have seen one such model chosen, and to have available all of the standard runs being provided for the IPCC Fourth Assessment by the major modeling centers, in the same format used by those models, so that the climate community could judge for itself the plausibility of this model's climate simulation.

Because high latitudes are thought to be most sensitive to greenhouse gas forcing owing to, for example, ice - albedo feedbacks, we focus on the tropical Pacific Ocean to derive a minimum value for long - term climate sensitivity.

My complaint concerns the putative conclusions that the narrator makes concerning climate sensitivity and the implications for the high end IPCC scenarios.

This gives a range of climate sensitivity that is much larger than the IPCC range (1.5 to 4.5 deg C for a doubling of CO2), and which therefore translates to wider bounds on possible climate projections both at the high end and low end.

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).

Analysis of the Pliocene (c.f. the Nature geoscience article by Lunt et al) would tend to support total climate sensitivities at or even beyond the high end of the IPCC range (I make that about 4.5 C for a doubling, extrapolating from Lunt's Pliocene warming).

The low sensitivity you quote is just as incredible as the high numbers discussed above (think about what it would imply for the glacial 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.

I've heard that sensitivity for current conditions is probably higher, but regardless, isn't that the first thing one would want answered about climate sensitivity?

-- Climate probably has a higher sensitivity for solar than for CO2, for the same change in forcing.

The high end of current estimates for climate sensitivity are already in very negative and serious terratory.

If aerosol forcing is high, then reconciling with recent warming demands very high climate sensitivity (which you see realized after the aerosols go away)-- and that would indeed mean we may have already passed the threshold for 2C warming.

also suggsts a higher climate sensitivity than 3C as do a multitude of papers looking at the past climates and there must be a lag in temperature rise and tree invasion of regions which might well mean that Northern areas are actually hotter than they have been for a long time, it just taking time for the proxies to catch up by growing.

Just for the sake of illustration, though, here's one scenario where higher Holocene variability could go along with lower climate sensitivity: Suppose that some unknown stabilizing mechanism makes the real world less sensitive to radiative forcing than our current models.

Conversely, if «climate sensitivity» for a doubling of CO2 is based on recent measurements and CO rates, and past natural variability is underestimated — as you've shown here — then this implies our estimates of sensitivity per CO2 doubling is too high, not too low.

What's new is that several recent papers have offered best estimates for climate sensitivity that are below four degrees Fahrenheit, rather than the previous best estimate of just above five degrees, and they have also suggested that the highest estimates are pretty implausible.

Even with almost no chance of the high end of climate sensitivity estimates being right, the odds of substantial, prolonged and disruptive climate change (and changes in ocean chemistry) are still plenty high enough to justify a sustained push toward an energy menu that works for the long haul.

Since 1990, observed sea level has followed the uppermost uncertainty limit of the Intergovernmental Panel on Climate Change (IPCC) Third Assessment Report (TAR), which was constructed by assuming the highest emission scenario combined with the highest climate sensitivity and adding an ad hoc amount of sea - level rise for «ice sheet uncertainty&raquClimate Change (IPCC) Third Assessment Report (TAR), which was constructed by assuming the highest emission scenario combined with the highest climate sensitivity and adding an ad hoc amount of sea - level rise for «ice sheet uncertainty&raquclimate sensitivity and adding an ad hoc amount of sea - level rise for «ice sheet uncertainty» (1).

«Our results indicate that the [divergence problem]-- including high - frequency loss in climate sensitivity and / or low - frequency trend offset — must be addressed at the local to regional level, before conclusions can be drawn for larger scales.

This sensitivity is often represented by the equilibrium climate sensitivity, but this quantity is poorly constrained with significant probabilities for high values.

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.

When the reseachers at the Center for International Climate and Environmental Research — Oslo (CICERO) applied their computer «model and statistics to analyse temperature readings from the air and ocean for the period ending in 2000, they found that climate sensitivity to a doubling of atmospheric CO2 concentration will most likely be 3.7 °C, which is somewhat higher than the IPCC prognosis.Climate and Environmental Research — Oslo (CICERO) applied their computer «model and statistics to analyse temperature readings from the air and ocean for the period ending in 2000, they found that climate sensitivity to a doubling of atmospheric CO2 concentration will most likely be 3.7 °C, which is somewhat higher than the IPCC prognosis.climate sensitivity to a doubling of atmospheric CO2 concentration will most likely be 3.7 °C, which is somewhat higher than the IPCC prognosis.»

There appears to be plenty of evidence for some places being warmer than today in the MWP, and whilst most studies say that globally it wasn't warmer it seems that scientists still want more data to be sure (and if it was warmer, that might suggest higher climate sensitivity).

Moreover, and significantly, the fact that they are already doing so is strong evidence that the overall sensitivity of the climate system is quite high, and that stabilization concentrations that were even recently considered to be manageably safe — 450 ppmCO2eq for example — are in fact quite dangerous.

In this light paleo research is very important too — as indeed when one looks at high - CO2 warm periods (for instance in the Tertiary) some data seems to suggest a climate sensitivity that would be somewhat higher than the IPCC range.

When I looked at historic temperature and CO2 levels, it was impossible for me to see how they could be in any way consistent with the high climate sensitivities that were coming out of the IPCC models.

And with high climate sensitivity, a risk - averse target for 2 ˚C is around 350ppm CO2e — and all this is necessary just to meet a 2 ˚C target that is actually dangerous.

He takes it as a proven given that temperature sensitivity to CO2 will be high, over ten degrees F for the likely CO2 increases we will see in the next century, which puts his «proven» climate sensitivity number higher than the range even in the last IPCC report.

As components of the global cryosphere, mountain glaciers are known for their high sensitivity to climate change.

Finally, we have not yet taken note here of Shindell»14 «Inhomogeneous forcing and transient climate sensitivity» which makes a very strong case not only for the unexpected aerosol loading from China being the culprit for the divergence, but also, unfortunately, for the case that a rather high sensitivity is a logical consequence of that explanation.

This assumption is based on climate model results that gave high climate sensitivity for doubling of CO2 by smoothing out all the oscillation in GMST before the 1970s and leaving untouched the warming phase of the oscillation since then and calling it man - made global warming as shown below.