Sentences with phrase «radiative forcing at»

Change radiative forcing at the tropopause or at TOA and everything in the climate system changes.

Many details have certainly some influence on the relationship between radiative forcing at the TOA (or tropopause) and the average temperature of the earth surface.

Note Collins et al. considers radiative forcing at all three levels.

Ramanthan emphasizes that it is not just the radiative forcing at the surface, but also the atmospheric warming from CO2 that amplifies the surface warming.

TerraPass on the other hand doesn't give you the option to include radiative forcing at all (though they do allow you to be more precise inasmuch as giving you different airline options).

Miller N. B., M. D. Shupe, C. J. Cox, D. Noone, P. O. G. Persson and K. Steffen (February 2017): Surface energy budget responses to radiative forcing at Summit, Greenland.

Global - annual mean adjusted radiative forcing at the top of the atmosphere is, in general, a reliable metric relating the effects of various climate perturbations to global mean surface temperature change as computed in general circulation models (GCMs).

Like the other metrics discussed above, global mean radiative forcing at the surface would not allow characterization of the regional structure of forcing.

Representative Concentration Pathway 6.0 (RCP6) is a pathway that describes trends in long - term, global emissions of greenhouse gases (GHGs), short - lived species, and land - use / land - cover change leading to a stabilisation of radiative forcing at 6.0 Watts per square meter (Wm − 2) in the year 2100 without exceeding that value in prior years.

That means the Arctic Amplification would have to come from «dynamics», not radiative forcing and it would have to occur just to catch up with the deficit in radiative forcing at the poles relative to the global mean.

As a consequence, like the RFTP: INST, the stratosphere - adjusted radiative forcing at the TOA is positive over all of Antarctica and, in the model presented herein, surface temperatures increase everywhere over that continent in response to quadrupled CO2.

This unique feature of the Antarctic atmosphere has been shown to result in a negative greenhouse effect and a negative instantaneous radiative forcing at the top of the atmosphere (RFTOA: INST), when carbon dioxide (CO2) concentrations are increased, and it has been suggested that this effect might play some role in te recent cooling trends observed over East Antarctica.

«Representative Concentration Pathway (RCP) 4.5 is a scenario of long - term, global emissions of greenhouse gases, short - lived species, and land - use - land - cover which stabilizes radiative forcing at 4.5 Watts per meter squared (W m - 2, approximately 650 ppm CO2 - equivalent) in the year 2100 without ever exceeding that value.»

It shows an ocean heat peak in the 1990's — that follows changes in cloud radiative forcing at toa.

The Clarke et al. (2007) scenario stabilized radiative forcing at approximately 4.7 W m − 2, slightly higher than RCP4.5.

Representative Concentration Pathway (RCP) 4.5 is a scenario of long - term, global emissions of greenhouse gases, short - lived species, and land - use - land - cover which stabilizes radiative forcing at 4.5 W m − 2 (approximately 650 ppm CO2 - equivalent) in the year 2100 without ever exceeding that value.

The RCP4.5 is only one possible pathway to stabilization of radiative forcing at 4.5 W / m2.

«Radiative forcing at high concentrations of well - mixed greenhouse gases,» Brendan Byrne and C. Goldblatt, Geophysical Research Letters, Jan 13 2014.

[Response # 2: The standard for comparing responses across different models is to look at the radiative forcing at the top of the atmosphere — for 2xCO2 it is around 4 W / m2 (read the new National Academies report on this for a much more detailed discussion of the concept).

I wrote: «CO2 has been shown in laboratory conditions to increase radiative forcing at the surface.»

A study released last month in the Journal of Geophysical Research: Atmospheres used three different models to run the same SSCE scenario in which sea - salt engineering was used in the low - latitude oceans to keep top - of - atmosphere radiative forcing at the 2020 level for 50 years and was then abruptly turned off for 20 years.

The DK12 feedback calculation is invalidated by focusing on noisy short - term data and failing to account for all radiative forcings at work, as well as all heat reservoirs, in particular the oceans below 700 meters.»

Not exact matches

A past study that Kravitz helped run at GeoMIP found that the abrupt termination of radiative forcing would cause global warming to effectively speed up to make up for all the time it lost, cramming five decades of warming into five or 10 years (ClimateWire, Nov. 27).

I am all for addressing CO2 and long - term change, but it makes no sense at all to be having continued positive radiative forcing from methane, for example, while we are waiting to get CO2 under control.

Climate model projections neglecting these changes would continue to overestimate the radiative forcing and global warming in coming decades if these aerosols remain present at current values or increase.

Pierre, could you comment on what, exactly, is new in the recent Philipona paper, compared with the two similar papers they published last year («Greenhouse forcing outweighs decreasing solar radiation driving rapid temperature rise over land», «Radiative forcing — measured at Earth's surface — corroborate the increasing greenhouse effect»)?

For this new idea to have merit, it had better have heat fluxes at least on par with the radiative forcing from CO2.

They, too, assume an equivalence in radiative forcing between GHG and aerosol, What they do is add different estimates of the aerosol radiative forcing to the GHG forcing, while keeping the temperature response fixed at the observed recent warming.

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.

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.

Your earlier # 182 was equally disconcerting where you quoted Norris and Slingo (2009) saying «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.»

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.

Now, for some purposes if you were looking at the very long term response to a very slowly varying radiative forcing, you might get away with treating the ocean with a deeper equivalent mixed layer.

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-.

However, some forcings in the general sense defined above don't have an easy - to - caclulate «radiative forcing» at all.

Shapiro et al estimate the total solar irradiance (TSI) during the Maunder minimum to be about 6 W / m2 less than at present, and hence the solar radiative forcing difference of about 1 W / m2.

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.

In other words, the same natural forcings that appear responsible for the modest large - scale cooling of the LIA should have lead to a cooling trend during the 20th century (some warming during the early 20th century arises from a modest apparent increase in solar irradiance at that time, but the increase in explosive volcanism during the late 20th century leads to a net negative 20th century trend in natural radiative forcing).

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.»

As for Wielecki, I'm not sure which red graph you are referring to, but if you mean the one at the top of the three - panel graph from the corrected version of the Science article, that is labeled «LW,» which, as I said in my response to Spencer Weart that is the TOA longwave radiative forcing.

rise is flawed & suggests one based on net (radiative) energy forcing — what do you at realclimate think about this?

Conclusion: Or result show indelibly that the pdf and cdf for Î?T2x very strongly depend on which radiative forcing factors have actually been at work during the period of instrumental temperature measurements»

It is found that a radiative forcing from non-CO2 gases of approximately 0.6 W m -LRB--2) results in a near balance of CO2 emissions from the terrestrial biosphere and uptake of CO2 by the oceans, resulting in near - constant atmospheric CO2 concentrations for at least a century after emissions are eliminated.»

As an aside, the radiative forcing by aerosols (in both long wave and solar radiation at the tropopause) is not the same as global dimming (which is a solar radiation effect at the surface) though they are related.

We at RC think that some of the Keenlyside results «predicting» an interruption of warming were overstated and misinterpreted, but for me personally the take - away message from Keenlyside is that ocean dynamics is capable of producing a temporary warming interruption, even in the face of growing radiative forcing.

Yes of course — the main variation is that, at any one moment in time, each unit increase of atmospheric CO2 has less radiative forcing than the last, following the logarithmic proportionality discussed earlier.

In fact, all climate models do predict that the change in globally - averaged steady state temperature, at least, is almost exactly proportional to the change in net radiative forcing, indicating a near - linear response of the climate, at least on the broadest scales.

but to reach more than 2 °C at the end of the century, there must be undoubtedly a detectable acceleration at some moment — and it is somewhat surprising that no hint for any acceleration is detectable after 30 years of continuous increase of radiative forcing, isn't it?

Given those assumptions, looking at the forcing over a long - enough multi-decadal period and seeing the temperature response gives an estimate of the transient climate response (TCR) and, additionally if an estimate of the ocean heat content change is incorporated (which is a measure of the unrealised radiative imbalance), the ECS can be estimated too.