Sentences with phrase «by aerosol effects»

Not exact matches

Scientists can measure how much energy greenhouse gases now add (roughly three watts per square meter), but what eludes precise definition is how much other factors — the response of clouds to warming, the cooling role of aerosols, the heat and gas absorbed by oceans, human transformation of the landscape, even the natural variability of solar strength — diminish or strengthen that effect.

By absorbing heat, aerosols can evaporate nearby cloud droplets — making the cloud less reflective and compounding the heating effect.

Aerosols can also have a cooling effect, if they are bright, like the sulfate particles emitted by volcanoes.

Geoengineering — the intentional manipulation of the climate to counter the effect of global warming by injecting aerosols artificially into the atmosphere — has been mooted as a potential way to deal with climate change.

«It is widely understood that aerosols have a net cooling effect on climate, counteracting the warming caused by greenhouse gases.

Despite its smaller ash cloud, El Chichn emitted more than 40 times the volume of sulfur - rich gases produced by Mt. St. Helens, which revealed that the formation of atmospheric sulfur aerosols has a more substantial effect on global temperatures than simply the volume of ash produced during an eruption.

Indeed, the reduction in the emission of precursors to polluting particles (sulphur dioxide) would diminish the concealing effects of Chinese aerosols, and would speed up warming, unless this effect were to be compensated elsewhere, for instance by significantly reducing long - life greenhouse gas emissions and «black carbon.»

«By reducing the amount of coal, we reduce the cooling effect of the aerosols.»

Past calculations of the cooling effect of aerosols have been inferred from «missing» global warming predicted by climate models.

The warming commitment if we stop all human emissions (GHG and aerosol) is probably very substantial: The cooling effect of the aerosol will very quickly disappear, thereby «unmasking» the greenhouse warming, approximately half of which has been canceled by aerosol cooling up to now.

The observed amount of warming thus far has been less than this, because part of the excess energy is stored in the oceans (amounting to ~ 0.5 °C), and the remainder (~ 1.3 °C) has been masked by the cooling effect of anthropogenic aerosols.

This mission is fulfilled by operating atmospheric observatories around the world that collect massive amounts of atmospheric measurements to provide data products that help scientists study the effects and interactions of clouds and aerosols and their impact on the earth's energy balance.

Aerosols tend to have a cooling effect by scattering sunlight and by encouraging clouds to form, preventing the sun's energy reaching Earth's surface.

Sally, who was nominated by Dr. Beat Schmid, Associate Director, Atmospheric Sciences and Global Change Division, was honored for her exceptional contribution in the field of atmospheric science, particularly in her efforts to improve understanding of the radiative effect of clouds and aerosols on the Earth's atmosphere and their representation in climate models.

Fascinatingly, the book from the mid-70s said that there was one climate scientist — Wally Broecker - who predicted that the greenhouse warming was on the verge of overtaking the aerosol cooling effects and that by the year 2000 the planet would be warmer than it had been in 1000 years.

Undersea volcanoes could not produce this effect because the dust and aerosols would be absorbed by the sea before they reached the atmosphere.

Paraphrasing the text in the post, aerosols that are input into the atmosphere, due to their spatial heterogeneity, also cause regions of heating or cooling that the atmosphere can respond to by changing its circulation — and that might have further climate effects in places far away from where the aerosols are input.

Most studies consider a range of anthropogenic forcing factors, including greenhouse gases and sulphate aerosol forcing, sometimes directly including the indirect forcing effect, such as Knutti et al. (2002, 2003), and sometimes indirectly accounting for the indirect effect by using a wide range of direct forcing (e.g., Andronova and Schlesinger, 2001; Forest et al., 2002, 2006).

The potential risks around sulfate aerosol solar geoengineering include alteration of regional precipitation patterns, its effects on human health, and the potential damage to Earth's ozone layer by increased stratospheric sulfate particles.

So, is there another aerosol effect (different of the adjustment) accounted by the models, or other things?

Ironically, future reductions of particulate air pollution may exacerbate global warming by reducing the cooling effect of reflective aerosols.

The indirect aerosol effect on clouds is non-linear [1], [76] such that it has been suggested that even the modest aerosol amounts added by pre-industrial humans to an otherwise pristine atmosphere may have caused a significant climate forcing [59].

Earth's measured energy imbalance has been used to infer the climate forcing by aerosols, with two independent analyses yielding a forcing in the past decade of about − 1.5 W / m2 [64], [72], including the direct aerosol forcing and indirect effects via induced cloud changes.

Scenes allude to the band's gloomy inclinations, bass - driven melodies and innovative use of audio effects (one band member uses an aerosol spray can to form a beat), but the story of Joy Division is an afterthought in the movie, replaced instead by a much more routine study of depression and the effects of sudden success and touring on a marriage.

But, as far as I can see, the «attacks» by vested interests are not even able to make legitimate points (e.g. uncertainty about the effects of clouds or aerosols in climate models).

Let me try to be more explicit: if you want to assume (or, if you prefer, conclude) that aerosols produced by the increased burning of fossil fuels after WWII had a cooling effect that essentially cancelled out the warming that would be expected as a result of the release of CO2 produced by that burning, then it's only logical to conclude that there exists a certain ratio between the warming and cooling effects produced by that same burning.

The ignoring of the effect of the aerosols by Victor shows a complete lack of interest in understanding the truth of the science or a purposeful desire to deflect reality.

With the cosmic ray effect we have ~ 0.3 C of solar warming combined with ~ 0.2 of CO2 warming, which is then offset by human - produced aerosols to yield ~ 0.3 of waring.

Fairly well characterized by aerosol index, with short term, very large effects, easily removed from a steady underlying trend

Subsequent work (for instance by Drew Shindell) has shown that the simplified EBMs are missing important transient effects associated with aerosols, and so the divergence is very likely less than AR5 assessed.

Research by an international team of scientists recently published in the journal Geophysical Research Letters says that the cooling effect of aerosols is so large that it has masked as much as half of the warming effect from greenhouse gases.

But models are not tuned to the trends in surface temperature, and as Gavin noted before (at least for the GISS model), the aerosol amounts are derived from simulations using emissions data and direct effects determined by changes in concentrations.

So, is there another aerosol effect (different of the adjustment) accounted by the models, or other things?

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.

They are therefore unaffected by a re-evaluation of the aerosol indirect effect.

This is a peer reviewed paper by respected scientists who are saying that aerosol forcing means that the majority of the warming caused by existing co2 emission has effectively been masked thus far, and that as aerosols remain in the atmosphere for far shorter a duration of time than co2, we will have already most likely crossed the 2 degree threshold that the G8 politicians have been discussing this week once the cooling effect of aerosols dissipate.

My question is: does the retroreflectivity of the larger droplets, i.e. back towards the light source, play into the sulfur aerosol issue or is it simply averaged out by the bulk effect of all the aerosol particles present in the apparently white haze?

I was thinking instead perhaps more easily controlled polar - orbit satellites might be used, which would rotate with some fixed ratio to their orbital period, casting greater shadows at higher latitudes... or some other arrangment... for a targetted offset polar amplification of AGW especially and in particular perhaps avoiding the reduction in precipitation that can be caused by SW - radiation - based «GE» (although aerosols that actually absorb some SW in the troposphere while shielding the surface would have the worst effect in that way, I'd think)... strategic distribution of solar shading has been suggested with precipitation effects in mind, such as here... sorry, I don't have the link (I'm sure I saved it, just as Steve Fish would suggest — but where?).

Let's see... many models show that aerosols could have been artificially keeping the world's average surface temperature cooler by about 3 - 5 degrees C from 1900 - 2000 --(sulfate aerosols certainly have some certifiable cooling effects cancelling out the warming effects of CO2).

What are you thinking about a fight against this effect by, for example, the injection in the higher tropsphere of very tiny (1 to 5 microns) aerosols?

... and all by itself... woops... a possible isolated, independent temperature rise of 3 - 5 degrees C average world surface temperatures by 2100, not even including any other positive forcings, because the forcing is already there waiting for the cancelling aerosol cooling effect to be removed...

However, under a climate mitigation scenario for the twenty - first century in which sulphate aerosols decline before atmospheric CO2 is stabilized, this «diffuse - radiation» fertilization effect declines rapidly to near zero by the end of the twenty - first century.»

The GCM's I know of (and as described by the IPCC 2001) do include a large cooling effect from aerosols.

And for those of you who want to insist that aerosols produced by the uncontrolled burning of coal neutralized the effects of AGW from 1940 to 1979, please explain how the same argument could not be made for the effects of coal - induced aerosols during this earlier period, when no constraints on the polluting effects of coal combustion were present at all.

Probably this effect is usually masked by variations in anthropogenic, volcanic or biogenic aerosols, and is revealed only in Antarctica where other signals are quiet.

The effect of both CO2 and aerosols by mass in the atmosphere are not linear and do not follow each other in lock step, hence to claim that aerosols would have a cancelling effect no matter what the rate of fossil fuel combustion would be a false assumption.

The bottom two panels demonstrate that this weakening is due entirely to the anthropogenic forcings — greenhouse gas increases offset by sulfate aerosol effects.

It might make sense to take a small portion of the aerosol that would have been dumped into the troposphere by retired dirty coal plants, and inject that directly into the stratosphere where it will restore the lost cooling effect while (hopefully) doing less harm than the old stuff dumped into the lower atmosphere.

Steve 440 says: «A recent paper by Douglas and Christy seems to claim that either 2C02 would lead to less than 1C or if 2C02 leads to greater than 1C then some forcing other than aerosols must be «masking» CO2's effect....»

The spotlight is on the effect of aerosol - particles released by industrial activity - on the Earth's climate.