Sentences with phrase «if aerosol cooling»

Not exact matches

China «could cause some decreases [in stratospheric aerosols] if that is the source,» Neely says, adding that growing SO2 emissions from India could also increase cooling if humans are the dominant cause of injecting aerosols into the atmosphere.

On the other hand, «if some volcanoes that are large enough go off and if they are the dominant cause [of increasing aerosols], then we will probably see some increases» in cooling.

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

If the aerosols are dispersed primarily in the Northern Hemisphere, the greater cooling in this hemisphere can also diminish the summertime heating that drives the northward migration of monsoon winds over Africa up to the Ethiopian highlands where the Blue Nile is supplied with its summer floodwaters.

I don't understand how temperatures will not rise if we clean out the troposphere and remove the aerosols which are now cooling.

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.

Now if this was the 1980s they might have had a point, but the fact that aerosols are an important climate forcing, have a net cooling effect on climate and, in part, arise from the same industrial activities that produce greenhouse gases, has been part of mainstream science for 30 years.

If you set the aerosol forcing to zero you don't get the mid-century interruption of warming, and if the aerosol forcing were allowed to get as big as, say, 10 W / m ** 2 you would get excessive cooling unless you imposed a very low climate sensitivity — which would then make it impossible to reproduce the post-1970's warminIf you set the aerosol forcing to zero you don't get the mid-century interruption of warming, and if the aerosol forcing were allowed to get as big as, say, 10 W / m ** 2 you would get excessive cooling unless you imposed a very low climate sensitivity — which would then make it impossible to reproduce the post-1970's warminif the aerosol forcing were allowed to get as big as, say, 10 W / m ** 2 you would get excessive cooling unless you imposed a very low climate sensitivity — which would then make it impossible to reproduce the post-1970's warming.

I'm sorry if it's boring — only as boring perhaps as unscientific guesswork about the extent of aerosol - induced cooling post-1940s perhaps, which many are more than happy to indulge in.

You can, of course, argue that other factors were at work in the early 20th century warming phase, but if you want to argue that the mid-century cooling was largely due to the neutralizing effect of industrial aerosol pollutants, then you can not, as did Rodgers, claim that any part of that earlier warmup was due to the burning of fossil fuels.

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.

Anyway, if soot aerosols are to blame, then a reduction of them would have a cooling effect, not a warming effect...

If you want to assume that aerosols resulting from pollution produced by the burning of fossil fuels were responsible for the cooling evident from 1940 through the late 70's, then you have no reason to claim ANY degree of warming due to CO2 forcing during any earlier period.

If sulfate aerosols nucleate cloud drops, resulting in a greater number of smaller droplets rather than a few large ones, this will further increase scattering and cooling.

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.

Furthermore, if aerosols did have such a dramatic cancelling effect at the onset of WWII and during the following decades, is aerosol cooling part of the temperature models?

If the influence of aerosols is less than expected, then the influence of CO2 must be decreased too, or it is impossible to explain the cooling period 1945 - 1975 with increasing CO2 levels.

The (GCM) models don't reflect reality anywhere if the direct and indirect cooling by (mostly) sulfate aerosols are not taken into account (see the IPCC graph.

It is conceivable that aerosol effects (which includes «smoke») could also affect the lapse rate, but the aerosols tend to warm where they are located and depending on the composition, cool below — this gives an impact that — if it was a large factor in the tropical mean — would produce changes even larger than predicted from the moist adiabatic theory.

The one slightly fortuitous aspect to this is that the forcing from CO2 alone is around 1.5 W / m2, while if you add up all of the forcings, including warming factors (like CO2 and CH4) and cooling factors (like aerosols), you end up with a total around 1.6 W / m2 — i.e. all of the extra stuff we've put in over the years pretty much cancels out in the global mean.

Rough calculations show if you drill about a dozen mine shafts as deep as possible into the thing, and plunk megaton nuclear bombs down there, and then fire them off simultaneously, you'll get a repeat of the Long Valley Caldera explosion of about 800,000 years ago — which coated everything east of it with miles of ash and injected a giant aerosol cloud into the stratosphere — the ash layer alone formed a triangle stretching from the caldera to Louisiana to North Dakota, including all of Arizona and most of Idaho and everything in between — I bet that would have a cooling factor of at least -30 W / m ^ 2 — and you could go and do the Yellowstone Plateau at the same time — geoengineering at its finest.

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.

I'm pretty sure you can get the grey version of that into a strat - cooling / trop - warming situation if you pick the strat absorbers right, but Andy is certainly right that non-grey effects play a crucial role in explaining quantitatively what is going on in the real atmosphere (that's connected with the non-grey explanation for the anomalously cold tropopause which I have in Chapter 4, and also with the reason that aerosols do not produce stratospheric cooling, and everything depends a lot on what level you are looking at).

If industry - generated aerosols have a more limited cooling effect than originally thought, we can clean up and scale down dirty coal plants without worrying too much about consequent sudden jumps in global temperatures of up to 2 degrees C (if I remember the upper limits of earlier studies correctlyIf industry - generated aerosols have a more limited cooling effect than originally thought, we can clean up and scale down dirty coal plants without worrying too much about consequent sudden jumps in global temperatures of up to 2 degrees C (if I remember the upper limits of earlier studies correctlyif I remember the upper limits of earlier studies correctly).

One wonders what we would do if injecting sulphate aerosols in the stratosphere were to cause a planet - wide cooling event far beyond the original intentions

For GHGs + aerosols, the low - to - mid latitudes in recent decades are too cold and the 1930 - 1940 period is even cooling further... If a model isn't able to reproduce reality (i.e. not validated), it is inapropriate to make any conclusions from the results... And the researchers clearly underplayed the solar cycles in these matters.

Multi-signal detection and attribution analyses, which quantify the contributions of different natural and anthropogenic forcings to observed changes, show that greenhouse gas forcing alone during the past half century would likely have resulted in greater than the observed warming if there had not been an offsetting cooling effect from aerosol and other forcings.

If we would pump aerosols in the stratosphere to artificially cool the Earth and thereby compensate (part of) the current climate warming, we would be permanently living under a slight sunshade.

If all of the cooling in the usa from 1950 to 1975 is caused by increasing aerosols (Schneider et al) then all of the warming since 1975 is caused by decreasing aerosols.

It is not clear from the text, if they already included the new AR5 reduced aerosol cooling which would further decrease sensitivity by 25 %.

In fact, the major effect of significant volcanic eruptions is cooling due to the sulfate aerosols that they release (although in order to have a significant cooling effect, the eruption has to be large enough that it injects the aerosols into the stratosphere where they can stay around longer... and it apparently helps if the eruption is reasonably near to the equator).

Second, if this is so (and it seems unreasonably large), why have we never observed this cooling effect in the regions with high concentrations of manmade aerosols.

If only GHG forcing is used, without aerosols, the surface temperature in the last decade or so is about 0.3 - 0.4 C higher than observations; adding in aerosols has a cooling effect of about 0.3 - 0.4 C (and so cancelling out a portion of the GHG warming), providing a fairly good match between the climate model simulations and the observations.

If the cooling from 1940 to 1975 was due (mainly) to aerosols, I would expect then that we would still be experiencing cooling, roughly equal to the 1960s, but certainly not warming faster than the pre-1940 era (when there was less volcanic activity, more active sun etc).

First, if significant aerosol concentrations only cover, say, 10 % of the globe, doesn't that mean that to get a 0.5 degree cooling effect for the whole Earth, there must be a 5 degree cooling effect in the affected area.

If one were to model the temperature rise in the years 1974 - 1999 it would be very easy to overestimate aerosol cooling and so to overestimate the value of CO2 climate sensitivity.

Aerosol cooling from volcanoes becomes irrelevant, etc. (ii) But even if I had based it on the point that averaging n times as many samples reduces the expected error by sqrt (n), what is «erroneous» about that?

How would the answer to this change if the pause was either A. an offset of GHG's and aerosols and other anthro cooling forcings, or B. an offset of GHG's by primarily (> 50 %) natural cooling trends?

To make a long story short, and this is really a WAGNER (wild assed guess, no explanation required) what if the large amounts of SO2 injected into the northern hemisphere atmosphere by WWII and the unrestrained coal burning (see London, smog) produced huge amounts of sulfate aerosol which shadowed and cooled downwind rural measurement sites.

However in John's recent weekly news (28 Dec) the 3rd article (Climate change 2013: Where we are now - not what you think) contained - «The new IPCC report tells us that half of warming (57 %) that should have already occurred has been masked by aerosols mostly emitted since the turn of the century in rapidly developing Asian nations (yes, warming would double if cooling smog pollutants were suddenly cleaned up in Asia).»

It's been a while, but we have an update in our Today's Paradox series: If aerosol climate cooling is underestimated, that means the trend line of the global temperature graph would lie higher than the one you get by... Continue reading →

None of the models — not one of them — could match the change in mean global temperature over the past century if it did not utilise a unique value of assumed cooling from aerosols.

If the alternative to losing power were attempting a rapid cooling of the planet through a sulfate aerosol shield, how would it play out?

If the aerosol hypothesis were correct then the global distribution of warming and cooling over the twentieth century would be matched by the model which was adjusted with the aerosol cooling.

If the maximum cooling ability of aerosols is only 1.0 Wm2, as Stevens suggests, the particles would offset only a third of warming caused by greenhouse gases.

If anthropogenic warming factors (mainly GHGs) are balanced out by anthropogenic cooling factors (mainly aerosols) then there should be only a very small.man - made trend.

One would think that, if this hypothesis were true, and if the rate of increase of aerosols is greater than the rate of increase in CO2 (which appears to be the case), and if aerosols do tend to cool, that there would have been net cooling over the 20 year period instead of a net plateau in temp increases.

It's a subtle argument, because aerosol cooling has clearly been less than greenhouse warming — if not, the planet wouldn't have gotten warmer over the last century.

If China spiits out more aerosols than anyone thought they would and the planet cools because of that — so be it.

Similarly, atmospheric aerosols, generally human - caused, can increase albedo and cool the planet — especially if they also increase cloudiness by providing condensation nuclei for WV.