Sentences with phrase «as radiative forcing»

You, Girma and many others in the skeptic community seem to have a problem discerning when CO2 increase acts as a radiative forcing and when it acts as a feedback.

With radiosonde data, both the composition and temperature profile of the atmosphere have both changed, so the change in OLR is not the same as radiative forcing.

In my reply to comment # 22, I assumed that the commenter was responding to previous comments # 14 and # 16 which deal with the issue of CO2 as a radiative forcing of climate.

Decades of research by hundreds of independent scientific and academic institutions around the globe have discovered that human - caused climate change involves forcings such as the radiative forcing of well - mixed greenhouse gases, as well as land cover changes.

Such a scaling of the land surface forcing provides a metric that can be expressed in the same units as radiative forcing.

The recent cooling in Antarctica has been put down to SAM, but «the surface warming amplifies as the radiative forcing increases, implying that the recent local cooling over the Antarctic will reverse at some point in the future.»

For this fit, we find that the contributions to the GMAST rise are in almost the same ratios as the radiative forcing changes over the interval.

These impact the overall energy balance of the planet, known as radiative forcing, which is what causes the global temperature to rise.

Due to the important role of ozone in driving temperature changes in the stratosphere as well as radiative forcing of surface climate, several different groups have provided databases characterizing the time - varying concentrations of this key gas that can be used to force global climate change simulations (particularly for those models that do not calculate ozone from photochemical principles).

With climate change of course, we have no such confidence, because of the enormous and rapid increase in GHGs, whose physical basis as a radiative forcing agent is well understand, and quantified.

And note that for this to be as important as the radiative forcing associated with anthropogenic CO2, you'd still need to multiply it by 20.

A large class of climate forcings can be translated into a common currency, known as radiative forcing.

As an example of the possible extreme change in radiative forcing in a 50 - year time horizon for Isaken et al (2011)'s 4 x CH4 (i.e. quadrupling the current atmospheric methane burden) case of additional emission of 0.80 GtCH4 / yr is 2.2 Wm - 2, and as the radiative forcing for the current methane emissions of 0.54 GtCH4 / yr is 0.48 Wm - 2, this give an updated GWP for methane, assuming the occurrence of Isaksen et al's 4 x CH4 case in 2040, would be: 33 (per Shindell et al 2009, note that AR5 gives a value of 34) times (2.2 / [0.8 + 0.48]-RRB- divided by (0.54 / 0.48) = 50.

[Response: You can't take any value that has the same units as the radiative forcing and multiply it by the sensitivity and expect to get anything sensible.

Given that there is continual heating of the planet, referred to as radiative forcing, by accelerating increases of carbon dioxide (Figure 1) and other greenhouses due to human activities, why is the temperature not continuing to go up?

A large class of climate forcings can be translated into a common currency, known as radiative forcing.

[Response: You can't take any value that has the same units as the radiative forcing and multiply it by the sensitivity and expect to get anything sensible.

Dynamical effects (changes in the winds and ocean circulation) can have just as large an impact, locally as the radiative forcing from greenhouse gases.

Several explanations for this widening have been proposed, such as radiative forcing due to greenhouse gas increase and stratospheric ozone depletion.

Radiative feedbacks act the same way as radiative forcings, except that they themselves are dependent on temperature changes (the distinction depends on timescale and context; also, in some contexts the feedbacks» effects are described as radiative forcings — for example, the radiative forcing of the increase in water vapor that would occur for a given temperature increase).

Not exact matches

The researchers [3] quantified China's current contribution to global «radiative forcing» (the imbalance, of human origin, of our planet's radiation budget), by differentiating between the contributions of long - life greenhouse gases, the ozone and its precursors, as well as aerosols.

Radiative forcing, especially that due to aerosols, is highly uncertain for the period 1750 - 1850 as there is little modeling and even less data to constrain those models.

As we explain in our glossary item, climatologists use the concept of radiative forcing and climate sensitivity because it provides a very robust predictive tool for knowing what model results will be, given a change of forcing.

This change in radiative forcing is described as «idealized» by the CMIP group [2].

, there is a lot of interesting stuff going on in Antarctica: the complexities of different forcings (ozone in particular), the importance of dynamical as well as radiative processes, and the difficulties of dealing with very inhomogeneous and insufficiently long data series.

Suppose also that — DESPITE THIS STABILIZING MECHANISM some as - yet unknown ocean circulation cycle operates that is the sole cause of the Holocene centennial scale fluctuations, and that this cycle has reversed and is operating today, yielding a temperature change that happens to mimic what models give in response to radiative forcing changes.

Stuber, N., M. Ponater, and R. Sausen, 2005: Why radiative forcing might fail as a predictor of climate change.

He then uses what information is available to quantify (in Watts per square meter) what radiative terms drive that temperature change (for the LGM this is primarily increased surface albedo from more ice / snow cover, and also changes in greenhouse gases... the former is treated as a forcing, not a feedback; also, the orbital variations which technically drive the process are rather small in the global mean).

His current research involves using WRF - chem as a tool to better understand the evolution of particulates and radiative forcing during recent DOE Atmospheric Sciences Program (ASP) field experiments.

In circunstances where these factors combine — planting trees as carbon offsets above the lcal tree line at high latitudes, modeling indicates that the radiative forcing impact can outwigh the benefits of carbon sequestration = cf

Similarly, many studies that attempt to examine the co-variability between Earth's energy budget and temperature (such as in many of the pieces here at RC concerning the Spencer and Lindzen literature) are only as good as the assumptions made about base state of the atmosphere relative to which changes are measured, the «forcing» that is supposedly driving the changes (which are often just things like ENSO, and are irrelevant to radiative - induced changes that will be important for the future), and are limited by short and discontinuous data records.

Let's set the stage by noting that, as a significant competitor to anthropogenic greenhouse forcing of recent climate change, the direct radiative forcing by solar irradiance variations is dead on arrival.

M2009 use a simplified carbon cycle and climate model to make a large ensemble of simulations in which principal uncertainties in the carbon cycle, radiative forcings, and climate response are allowed to vary, thus yielding a probability distribution for global warming as a function of time throughout the 21st century.

As long as the temporal pattern of variation in aerosol forcing is approximately correct, the need to achieve a reasonable fit to the temporal variation in global mean temperature and the difference between Northern and Southern Hemisphere temperatures can provide a useful constraint on the net aerosol radiative forcing (as demonstrated, e.g., by Harvey and Kaufmann, 2002; Stott et al., 2006cAs long as the temporal pattern of variation in aerosol forcing is approximately correct, the need to achieve a reasonable fit to the temporal variation in global mean temperature and the difference between Northern and Southern Hemisphere temperatures can provide a useful constraint on the net aerosol radiative forcing (as demonstrated, e.g., by Harvey and Kaufmann, 2002; Stott et al., 2006cas the temporal pattern of variation in aerosol forcing is approximately correct, the need to achieve a reasonable fit to the temporal variation in global mean temperature and the difference between Northern and Southern Hemisphere temperatures can provide a useful constraint on the net aerosol radiative forcing (as demonstrated, e.g., by Harvey and Kaufmann, 2002; Stott et al., 2006cas demonstrated, e.g., by Harvey and Kaufmann, 2002; Stott et al., 2006c).

Increased solar irradiance is an easy radiative forcing to calculate, as is the value for well - mixed greenhouse gases.

Could the climate forcing itself, such as increasing GHGs, affect parameterizations independently of the larger scale climate changes (for example, by changing thermal damping of various kinds of waves, or by changing the differences of radiative effects between different amounts and kinds of clouds)?

Maybe it was due to changes in CO2 radiative forcing (in part) since historical CO2 levels weren't as stable as assumed by the IPCC, at least that's what van Hoof et al. conclude from CO2 data derived from stomatal frequency analysis.

Despite your insistence otherwise, you evince at best a shallow understanding of basic principles of climate science (hint: while radiative forcing is known to be at least partially controlled by atmospheric CO2, no «natural», i.e. internal source of variability has been demonstrated that could drive a global temperature trend for half a century), as well as an inability to recognize genuine expertise.

Since OHC uptake efficiency associated with surface warming is low compared with the rate of radiative restoring (increase in energy loss to space as specified by the climate feedback parameter), an important internal contribution must lead to a loss rather than a gain of ocean heat; thus the observation of OHC increase requires a dominant role for external forcing.

Reliable data on decadal variability of the Earth's radiation budget are hard to come by, but to provide some reality check I based my setting of the scaling factor between radiative forcing and the SOI / PDOI index on the tropical data of Wielecki et al 2002 (as corrected in response to Trenberth's criticism here.)

Earth's energy balance In response to a positive radiative forcing F (see Appendix A), such as characterizes the present - day anthropogenic perturbation (Forsteret al., 2007), the planet must increase its net energy loss to space in order to re-establish energy balance (with net energy loss being the difference between the outgoing long - wave (LW) radiation and net incoming shortwave (SW) radiation at the top - of - atmosphere (TOA)-RRB-.

He goes so far as to say that the IPCC is biased against «internal radiative forcing,» in favor of treating cloud effects as feedback.

A lot of the remaining variability you see averages out over the annual cycle, and as I said, if you just take the part that actually correlates with PDO and SOI, you'd get an even smaller radiative forcing coefficient.

I certainly read the «internal radiative forcing» idea as something like this (actually I didn't see any other way to interpret it).

Calculations of «Cloud radiative forcing» (which is a specific kind of diagnostic — Cess et al definition) are not the same as the «radiative forcing» in the sense of CO2.

Gerald Marsh offered this opinion in «A Global Warming Primer» (page 4 - excerpt) «Radiative forcing is defined as the change in net downward radiative flux at the tropopause resulting from any process that acts as an external agent to the climate system; it is generally measured iRadiative forcing is defined as the change in net downward radiative flux at the tropopause resulting from any process that acts as an external agent to the climate system; it is generally measured iradiative flux at the tropopause resulting from any process that acts as an external agent to the climate system; it is generally measured in W / m2.

Consequently, as they say slightly earlier in the abstract: «At present, it is not known whether changes in cloudiness will exacerbate, mitigate, or have little effect on the increasing global surface temperature caused by anthropogenic greenhouse radiative forcing.»

It's what enables him to wipe out the unrealistically large interannual short - term fluctuations you would get by assuming a fluctuation in the radiative forcing as large as he assumed.

In Spencer and Braswell (2008), and to an even greater extent in his blog article, Spencer tries to introduce the rather peculiar notion of «internal radiative forcing» as distinct from cloud or water vapor feedback.

The difference in TSI between Shapiro et al and most other recent reconstructions (between Maunder minimum and the present) is about a factor of 10, but the difference in radiative forcing as quoted in this post (see the paragraph below) is only a factor of 2.