Sentences with phrase «global radiative forcing»

Trapp, R.J., N.S. Diffenbaugh, H.E. Brooks, M.E. Baldwin, E.D. Robinson, and J.S. Pal, 2007: Severe thunderstorm environment frequency during the 21st century caused by anthropogenically enhanced global radiative forcing, PNAS 104 no. 50, 19719 - 19723, Dec. 11, 2007.

What was new and only briefly mentioned was that «many gases produce indirect effects on the global radiative forcing».

Our findings regarding global radiative forcing by contrail cirrus will allow their effects to be included in studies assessing the impacts of aviation on climate and appropriate mitigation options.

Regional radiative forcing may provide a better measure of regional climate response than global radiative forcing, but further work is needed to quantify the links of regional radiative forcing to regional and global climate response.

[12] R.J. Trapp, N.S. Diffenbaugh, H.E. Brooks, M.E. Baldwin, E.D. Robinson, and J.S. Pal, «Changes in severe thunderstorm environment frequency during the 21st century caused by anthropogenically enhanced global radiative forcing,» Proc.

A simple method for estimating the global radiative forcing caused by the sea - ice - albedo feedback in the Arctic is presented.

So the 3.7 W m - 2 calculation for global radiative forcing could be refined perhaps by an improved experimental design (not necessarily by improved radiative transfer models) running RT models at each grid cell over the globe, over the diurnal cycle and the annual cycle for say 30 years, for the two different CO2 concentrations, such a detailed calculation would refine the 3.7 value.

Prevdi and Polvani (2014) suggest quite convincingly that this is a significant constraint in the use of external mean global radiative forcing.

That is global radiative feedback < global radiative forcing.

Trapp, R. J., N. S. Diffenbaugh, H. E. Brooks, M. E. Baldwin, E. D. Robinson, and J. S. Pal, 2007: Changes in severe thunderstorm environment frequency during the 21st century caused by anthropogenically enhanced global radiative forcing.

Even if the graphic in question depicted responses to the total global radiative forcing, to cherrypick a single model run and ignore the fact that it displays an anomalous spike in 2011 reveals exceptionally poor data analysis on Easterbrook's part.

You are welcome to try something similar with global radiative forcing fluctuation, but if you do it will be rather tricky to isolate the cloud effect, since you have the snow and ice albedo effect to deal with then, which are largely temperature - related feedbacks.

Some other forcings have a very small global radiative forcing and yet lead to large impacts (orbital changes for instance) through components of the climate that aren't included in the default set - up.

They thereby estimated that China contributes an average of 10 % to current, global radiative forcing.

This mostly reflects the response to global radiative forcings, which are dominated by anthropogenic forcing over the 20th Century.

It is also important to recognize that changes in the global radiative forcings (global warming or cooling) represent only a subset of climate change.

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).

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.

China's stated aim of improving air quality over the coming years would change this radiative forcing, leading to a rather counter-intuitive consequence; the increase in China's contribution to global warming.

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.

Near - global satellite aerosol data imply a negative radiative forcing due to stratospheric aerosol changes over this period of about — 0.1 W / m2, reducing the recent global warming that would otherwise have occurred.

James A. Edmonds • Member, IPCC Steering Committee on «New Integrated Scenarios» (2006 - present) • Lead Author, Working Group III, «Framing Issues,» IPCC Fourth Assessment Report (2007) • Lead Author, Working Group III, «Global, Regional, and National Costs and Ancillary Benefits of Mitigation,» IPCC Third Assessment Report (2001) • Lead Author, Working Group III, «Decision - Making Frameworks,» IPCC Third Assessment Report (2001) • Lead Author, Working Group III, Summary for Policy Makers, IPCC Third Assessment Report (2001) • Lead Author, Working Group II, «Energy Supply Mitigation Options,» IPCC Second Assessment Report (1996) • Lead Author, Working Group II, «Mitigation: Cross-Sectoral and Other Issues,» IPCC Second Assessment Report (1996) • Lead Author, Working Group III, «Estimating the Costs of Mitigating Greenhouse Gases,» IPCC Second Assessment Report (1996) • Lead Author, Working Group III, «A Review of Mitigation Cost Studies,» IPCC Second Assessment Report (1996) • Lead Author, Working Group III, «Integrated Assessment of Climate Change: An Overview and Comparison of Approaches and Results,» IPCC Second Assessment Report (1996) • Lead Author, IPCC Special Report, Climate Change 1994: Radiative Forcing of Climate Change and An Evaluation of the IPCC IS92 Emission Scenarios (1994) • Lead Author, IPCC Special Report, Climate Change 1992: The Supplementary Report to the IPCC Scientific Assessment (1992) • Major contributor, IPCC First Assessment Report, Working Group III, Response Strategies Working Group (1991).

The mechanism for reducing anthropogenic global warming, initiated through radiative forcing of greenhouse gases, is to stop emissions and reduce their concentration in the atmosphere to levels which do not stimulate carbon feedbacks.

Takemura, T., et al., 2002: Single scattering albedo and radiative forcing of various aerosol species with a global three - dimensional model.

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).

The regional climate feedbacks formulation reveals fundamental biases in a widely - used method for diagnosing climate sensitivity, feedbacks and radiative forcing — the regression of the global top - of - atmosphere radiation flux on global surface temperature.

«They're pretty evenly distributed across the atmosphere,» said Stephen Montzka, a NOAA scientist who monitors global changes in HFCs and studies their radiative forcing effects over time.

We note, however, that Mount Pinatubo does not provide a perfect proxy for global warming, because the nature of the external radiative forcing obviously differs between the two.

Abstract:» The sensitivity of global climate with respect to forcing is generally described in terms of the global climate feedback — the global radiative response per degree of global annual mean surface temperature change.

Therefore, the total annual and global mean radiative forcing during the LGM is likely to have been approximately — 8 W m — 2 relative to 1750, with large seasonal and geographical variations and significant uncertainties (see Section 6.4.1).

Ice sheet albedo forcing is estimated to have caused a global mean forcing of about — 3.2 W m — 2 (based on a range of several LGM simulations) and radiative forcing from increased atmospheric aerosols (primarily dust and vegetation) is estimated to have been about — 1 W m — 2 each.

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., 2006c).

A clear explanation of radiative forcing, CO2 infrared opacity and how additional atmospheric CO2 will contribute to significant warming would be important to many of trying to explain the physics of global warming.

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.

While the local, seasonal climate forcing by the Milankovitch cycles is large (of the order 30 W / m2), the net forcing provided by Milankovitch is close to zero in the global mean, requiring other radiative terms (like albedo or greenhouse gas anomalies) to force global - mean temperature change.

On the possibility of a changing cloud cover «forcing» global warming in recent times (assuming we can just ignore the CO2 physics and current literature on feedbacks, since I don't see a contradiction between an internal radiative forcing and positive feedbacks), one would have to explain a few things, like why the diurnal temperature gradient would decrease with a planet being warmed by decreased albedo... why the stratosphere should cool... why winters should warm faster than summers... essentially the same questions that come with the cosmic ray hypothesis.

Changes in the planetary and tropical TOA radiative fluxes are consistent with independent global ocean heat - storage data, and are expected to be dominated by changes in cloud radiative forcing.

/ /» This study indicates that the IPCC models are overpredicting global warming in response to positive radiative forcing.»

Gavin disputes that the main driver of the sea ice retreat is the albedo flip, but we are seeing not only polar amplification of global warming but positive feedback, which would not be explained simply by radiative forces and ocean currents.

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.»

Mike's work, like that of previous award winners, is diverse, and includes pioneering and highly cited work in time series analysis (an elegant use of Thomson's multitaper spectral analysis approach to detect spatiotemporal oscillations in the climate record and methods for smoothing temporal data), decadal climate variability (the term «Atlantic Multidecadal Oscillation» or «AMO» was coined by Mike in an interview with Science's Richard Kerr about a paper he had published with Tom Delworth of GFDL showing evidence in both climate model simulations and observational data for a 50 - 70 year oscillation in the climate system; significantly Mike also published work with Kerry Emanuel in 2006 showing that the AMO concept has been overstated as regards its role in 20th century tropical Atlantic SST changes, a finding recently reaffirmed by a study published in Nature), in showing how changes in radiative forcing from volcanoes can affect ENSO, in examining the role of solar variations in explaining the pattern of the Medieval Climate Anomaly and Little Ice Age, the relationship between the climate changes of past centuries and phenomena such as Atlantic tropical cyclones and global sea level, and even a bit of work in atmospheric chemistry (an analysis of beryllium - 7 measurements).

It actually has something like 100x the global warming impact (radiative forcing) of CO2.

The global mean aerosol radiative forcing caused by the ship emissions ranges from -12.5 to -23 mW / m ^ 2, depending on whether the mixing between black carbon and sulfate is included in the model.

Abstract:» The sensitivity of global climate with respect to forcing is generally described in terms of the global climate feedback — the global radiative response per degree of global annual mean surface temperature change.

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.

It's painfully easy to paint oneself logically into a corner by arguing that either (i) vigorous natural variability caused 20th century climate change, but the climate is insensitive to radiative forcing by greenhouse gases; or (ii) the climate is very sensitive to greenhouse gases, but we still are able to attribute details of inter-decadal wiggles in the global mean temperature to a specific forcing cause.

Jain, A.K., et al., Radiative forcings and global warming potentials of 39 greenhouse gases.