Sentences with phrase «estimates of the climate sensitivity as»

I again used the variance in our estimate of climate sensitivity as an indicator of uncertainty — if you are unclear about what that means, refresh your memory here.

Not exact matches

By studying the relationship between CO2 levels and climate change during a warmer period in Earth's history, the scientists have been able to estimate how the climate will respond to increasing levels of carbon dioxide, a parameter known as «climate sensitivity».

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.

In the figure in this article below, 10 out of 17 recent climate sensitivity estimates are 2C or lower (3 IPCC estimates counted as 1): http://www.cato.org/blog/current-wisdom-even-more-low-climate-sensitivity-estimates

We show how the maintained consensus about the quantitative estimate of a central scientific concept in the anthropogenic climate - change field — namely, climate sensitivity — operates as an «anchoring device» in «science for policy».

Dr. Benestad states: «They take the ratios of the amplitude of band - passed filtered global temperatures to similarly band - passed filtered solar signal as the estimate for the «climate sensitivity».

They take the ratios of the amplitude of band - passed filtered global temperatures to similarly band - passed filtered solar signal as the estimate for the «climate sensitivity».

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.

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.

If you want to estimate climate sensitivity to doubling CO2, don't you need to estimate as precisely as possible the direct and indirect effects of each forcing on temperature trends?

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.

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.

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.

It is important to regard the LGM studies as just one set of points in the cloud yielded by other climate sensitivity estimates, but the LGM has been a frequent target because it was a period for which there is a lot of data from varied sources, climate was significantly different from today, and we have considerable information about the important drivers — like CO2, CH4, ice sheet extent, vegetation changes etc..

Whether the observed solar cycle in surface temperature is as large as.17 K (as in Camp and Tung) or more like.1 K (many previous estimates) is somewhat more in doubt, as is their interpretation in terms of low thermal inertia and high climate sensitivity in energy balance models.

We show how the maintained consensus about the quantitative estimate of a central scientific concept in the anthropogenic climate - change field — namely, climate sensitivity — operates as an «anchoring device» in «science for policy».

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.

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).

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).

The IPCC range, on the other hand, encompasses the overall uncertainty across a very large number of studies, using different methods all with their own potential biases and problems (e.g., resulting from biases in proxy data used as constraints on past temperature changes, etc.) There is a number of single studies on climate sensitivity that have statistical uncertainties as small as Cox et al., yet different best estimates — some higher than the classic 3 °C, some lower.

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.

As noted earlier, our main conclusions are insensitive to the precise details of the forcing estimates used, the volcanic scaling assumptions made, and the precise assumed climate sensitivity.

My preference would be to refer to these as estimates of «effective climate sensitivity» rather than ECS.

[T] here have now been several recent papers showing much the same — numerous factors including: the increase in positive forcing (CO2 and the recent work on black carbon), decrease in estimated negative forcing (aerosols), combined with the stubborn refusal of the planet to warm as had been predicted over the last decade, all makes a high climate sensitivity increasingly untenable.

As the comment from Covey et al makes clear, he is calculating a sensitivity to surface energy fluxes that is almost 100x larger than standard estimates of the climate sensitivity.

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.

Now comes a new entry in the effort to specify the value known as «climate sensitivity,» and it falls on the low side of the existing estimates.

However, studies as far back as the 1960s have shown that an estimated Charney climate sensitivity of about 3 C seems about right, so I guess you could say that there has been no progress.

So, as far I as (try to slowly) understand, XXth century (even the last 1000 years) is unuseful to estimate empirically climate sensitivity because of the too slight variations involved.

The innocent layperson may have thought that looming climate change damages would be enough, but that isn't the case for the lower range of sensitivity estimates, again as EPA's own table shows.

Using the IPCC model - based estimate for climate sensitivity and the same logarithmic calculation as for the UK alone, we will have averted 1.2 °C of warming by 2100 by shutting down the world carbon - based economy.

Using the business - as - usual scenario for GHG radiative forcing (RCP8.5) and their novel estimate of Earth's warm - phase climate sensitivity the authors find that the resulting warming during the 21st century overlaps with the upper range of the Coupled Model Intercomparison Project Phase 5 (CMIP5) climate simulations.

It's NOT a matter of me being «stubborn», it is a matter of you failing to cite studies providing empirical evidence to support the Myhre et al. estimates of 2xCO2 climate sensitivity (upon which the whole IPCC CAGW house of cards rests), as requested by Jim Cripwell and myself.

There are hypothetical estimates of climate sensitivity; so far as I am aware no - one has measured a value for climate sensitivity.

My estimate that, since there is no CO2 signal in any modern temperature / time graph, the value of climate sensitivity is probably indistinguishable from zero, is a much simpler way of doing the estimations, and is probably as good as any other guess.

However as we document in the Lewis / Crok report, the IPCC was well aware of these recently published lower estimates of climate sensitivity.

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.

The most popular observationally - constrained method of estimating climate sensitivity involves comparing data whose relation to S is too complex to permit direct estimation, such as temperatures over a spatio - temporal grid, with simulations thereof by a simplified climate model that has adjustable parameters for setting S and other key climate properties.

Based on these sensitivities and observed climate trends, we estimate that warming since 1981 has resulted in annual combined losses of these three crops representing roughly 40 Mt or $ 5 billion per year, as of 2002.

I find Nic Lewis's estimate of 1.6 C for climate sensitivity as a strong indication that previous estimates by the IPCC were exaggerated.

Please address the issue as to whether previous IPCC estimates of climate sensitivity have been exaggerated.

As the name suggests, climate sensitivity is an estimate of how sensitive the climate is to an increase in a radiative forcing.

(The «I think» was because I was hoping to extricate myself from CE for a while to finish off a paper explaining why climate sensitivity as currently defined can neither be measured nor estimated with an error bar less than 1 C per doubling, and proposing a different definition that shrinks the error bar by an order of magnitude.

As these figures show, estimates from both models and observational data consistently find that the most likely climate sensitivity value is approximately 3 °C for a doubling of CO2.

Traditionally, only fast feedbacks have been considered (with the other feedbacks either ignored or treated as forcing), which has led to estimates of the climate sensitivity for doubled CO2 concentrations of about 3 ◦ C.

But when data contains a weaker «message» — as when estimating climate sensitivity — the choice of prior can greatly influence the final answer, and therefore be very contentious.

Their Summary for Policymakers includes an expanded range of climate sensitivity estimates, compared to the IPCC's 2007 assessment, of 1.5 ° -4.5 °C with a likelihood defined as 66 - 100 % probability.

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).

A method of dealing with the lack of mass balance measurements is to estimate the changes in mass balance as a function of climate, using mass balance sensitivities (see Box 11.2 for definition) and observed or modelled climate change for glacier covered regions.

But arguments over the precise value of climate sensitivity duck the wider point, which is that even if we're lucky and climate sensitivity is on the low side of scientists» estimates, we're still heading for a substantial level of warming by the end of the century if greenhouse gas emissions aren't addressed, as the IPCC has highlighted.