Sentences with phrase «effects of aerosols because»

Then, after giving a talk to the Bush - Cheney White House, he agonized about whether he should have ignored the cooling effects of aerosols because it gave Cheney an «out,» enabling him and others to make the specious argument that aerosols somehow balance out the trillions of tons of CO2 emitted every year.

Not exact matches

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.

An adjustment is necessary because as climate models are continually evaluated against observations evidence has become emerged that the strength of their aerosol - cloud interactions are too strong (i.e. the models» «aerosol indirect effect» is larger than inferred from observations).

From the Physical Science Basis: «Shindell et al. (2009) estimated the impact of reactive species emissions on both gaseous and aerosol forcing species and found that ozone precursors, including methane, had an additional substantial climate effect because they increased or decreased the rate of oxidation of SO2 to sulphate aerosol.

There is very high confidence that the net 20th C aerosol effect was a cooling — mostly because estimates of tropospheric sulphate aerosols dominate the changes, and because BC and OC changes for many sources almost balance out.

[Of course, this experiment is faulty b / c the thermal mass of the water is acting like a hot water bottle...] Conceptually, however, you can show your students the diffusion effect associated with CO2 and H2O, that the heat will eventually work its way out of the water into its surroundings [like heat trapped in a hot rock], and that climate science is a complex endeavor because the CO2 signal is not the sole factor out there [although one of the only man - made ones — others: water, aerosols, sun, et aOf course, this experiment is faulty b / c the thermal mass of the water is acting like a hot water bottle...] Conceptually, however, you can show your students the diffusion effect associated with CO2 and H2O, that the heat will eventually work its way out of the water into its surroundings [like heat trapped in a hot rock], and that climate science is a complex endeavor because the CO2 signal is not the sole factor out there [although one of the only man - made ones — others: water, aerosols, sun, et aof the water is acting like a hot water bottle...] Conceptually, however, you can show your students the diffusion effect associated with CO2 and H2O, that the heat will eventually work its way out of the water into its surroundings [like heat trapped in a hot rock], and that climate science is a complex endeavor because the CO2 signal is not the sole factor out there [although one of the only man - made ones — others: water, aerosols, sun, et aof the water into its surroundings [like heat trapped in a hot rock], and that climate science is a complex endeavor because the CO2 signal is not the sole factor out there [although one of the only man - made ones — others: water, aerosols, sun, et aof the only man - made ones — others: water, aerosols, sun, et al]

... 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...

In other words, if we are after a cause (or causes) for the temperature increase during the period in question, the presence or absence of aerosols from volcanic eruptions is beside the point, because they can not explain any increase in temperatures that occurred prior to any cooling effect they might have had.

But aren't these way too low, since LOTI shows we are — as of 2017 — already around 0.95 C warmer than the 1951 - 1980 average, and there is more warming «in the pipeline» because of the time lag, and another (estimated) 0.5 C warming when the anthropogenic aerosols dimming effect is removed?

The picture is complicated because different kinds of aerosols can have different effects: black carbon or soot has warming rather than a cooling effect, for instance.

First, for changing just CO2 forcing (or CH4, etc, or for a non-GHE forcing, such as a change in incident solar radiation, volcanic aerosols, etc.), there will be other GHE radiative «forcings» (feedbacks, though in the context of measuring their radiative effect, they can be described as having radiative forcings of x W / m2 per change in surface T), such as water vapor feedback, LW cloud feedback, and also, because GHE depends on the vertical temperature distribution, the lapse rate feedback (this generally refers to the tropospheric lapse rate, though changes in the position of the tropopause and changes in the stratospheric temperature could also be considered lapse - rate feedbacks for forcing at TOA; forcing at the tropopause with stratospheric adjustment takes some of that into account; sensitivity to forcing at the tropopause with stratospheric adjustment will generally be different from sensitivity to forcing without stratospheric adjustment and both will generally be different from forcing at TOA before stratospheric adjustment; forcing at TOA after stratospehric adjustment is identical to forcing at the tropopause after stratospheric adjustment).

From sheer thermal inertia of the oceans, but also because if you close down all coal power stations etc., aerosol pollution in the atmosphere, which has a sizeable cooling effect, will go way down, while CO2 stays high.

The contribution of greenhouse gases is greater than the observed warming, while the total anthropogenic contribution is thought to be around 0.7 °C because of the cooling effect of aerosols.

In their calculations, the direct tropo - spheric aerosol effect does not play a large net role, because the moderately absorbing aerosol assumption leads to an offset between its sunlight reflecting and absorbing properties insofar as the top of the atmosphere irradiance change is concerned.

If he means from latitude 70N (he doesn't say) at 6 % of Earth surface that would be +0.20 w / m ** 2 of aerosol forcing which I would have thought deserved its own line because of its contrary effect to aerosols elsewhere.

Not it is not similar because one event injected sulfate aerosols into the stratosphere where they stayed for years and affected the globe while the other («human particulates and aerosol pollution») were produced in the troposphere and have a residency time in the atmosphere of about 4 days and had only a regional effect.

I write it off as a very real effect that is not well characterized by the models, probably because these models don't model with enough accuracy the effect of the additional aerosol particles on cloud production to properly account for it's full effect on temperature.

The layer has been declining since the 1970s because of the effect of man - made chemicals, chiefly chlorofluorocarbons (CFCs) and similar gases, used mainly in refrigerants and aerosols.

Well it's even more complex than that because the net warming from humans doesn't just involve CO2, but other greenhouse gases and it factors in the cooling effect of aerosols being dwarfed by the CO2 forcing.

This is because of the warming effect of non-CO2 greenhouse gases usually equalling or exceeding the cooling effect of aerosols.

(PS — I don't remember my entire comment, but part of it had to do with the fact that in dividing up attribution for the forcings responsible for post-1950 warming, uncertainties regarding anthropogenic sulfate aerosols are not particularly important, because their net cooling effect wouldn't influence the percentage apportionment among the warming factors)

The second issue raised in our Science paper (now available free, see bottom of this post) is that perhaps there shouldn't yet have been substantial long - term trends in hurricane intensity — whether we would be able detect them above the natural variability or not — because until the last couple of decades, aerosol cooling effects on hurricanes have been counteracting the effects of greenhouse gas warming.

There is a fairly large degree of uncertainty in these figures, primarily because the magnitude of the cooling effect from human aerosol emissions is not well known.

If the direct effect of the aerosol increase is considered, surface temperatures will not get as warm because the aerosols reflect solar radiation.

«There is nothing inherently wrong with defining aerosol changes to be a forcing, but it is practically impossible to accurately determine the aerosol forcing because it depends sensitively on the geographical and altitude distribution of aerosols, aerosol absorption, and aerosol cloud effects for each of several aerosol compositions.

They get > 100 % because they argue that the anthropogenic warming effects have to overcome the aerosol cooling (and therefore give the same net warming as the total warming since 1950), though most people count aerosols as part of the anthropogenic effect, which causes the confusion.

So far, the initial effect is still relatively small for two reasons: (i) part of that effect has been canceled temporarily by increases in sulfate aerosol, and (ii) the warming has been delayed because it takes a long time for the vast mass of the ocean to heat up.

Karsten: So the take - home message would then be that 1) In the mid-century the NH cooled because of anthropogenic aerosols (especially the most polluted areas) 2) Now anthropogenic aerosols have a larger content of absorptive elements so directly observing this cooling in the most polluted areas is very complicated but we can nevertheless be sure that the global effect of these aerosols is markedly negative.

In this and other articles dealing with global warming, there is a disturbing tendency to view atmospheric aerosols, as beneficial because of their cooling effect.

In any event, all of these calcs are B S because we don't really understand the sum total of past / present and future aerosol effects nor of CO2 feedbacks nor of the combo of CO2 feedbacks with changing aerosols nor of natural low frequency climatic variation.

This is because the net warming it reports includes the cooling effects of aerosols which partly masks the warming caused by greenhouse gases.

Read more: Stanford University Aerosols Also Implicated in Glacier Melting, Changing Weather Patterns Other research examining the effects of soot on melting glaciers and changing weather pattens in South Asia has reached similar conclusions: Beyond increasing atmospheric warming, because the soot coats the surface of the snow and ice it changes the albedo of the surface, allowing it to absorb more sunlight and thereby accelerating melting.

Bryan, well aerosols and cloud albedo may be having an effect too, but the effects of CO2 aren't really being debated because they are understood very well.

But mainly because of uncertainty in the aerosol effect, the overall net forcing is quite uncertain, but still indicated to be positive.

On one hand, the reduction in global SO2 emissions reduces the role of sulfate aerosols in determining future climate toward the end of the 21st century and therefore reduces one aspect of uncertainty about future climate change (because the precise forcing effect of sulfate aerosols is highly uncertain).

Because of the too - high sensitivity they also over-predict volcanic cooling effects, but the AR5 assumed forcings minimize that problem by halving volcanic aerosol forcing over previously used (and in the case of Pinatubo, observed) values.

Quantifying the net human influence on the climate is a more difficult task, because the magnitude of the cooling effect from aerosols remains highly uncertain.

If we add in the warming effects of the other long - lived greenhouse gases, the best estimate rises to 1.22 °C surface warming caused by human emissions (we've only observed ~ 0.8 °C warming because much of that has been offset by human aerosol emissions).

(By the way, for those of you who already know about global cooling / dimming and aerosols, I will just say for now that these effects can not be making the blue line go down because the IPCC considers these anthropogenic effects, and therefore in the pink band.