Sentences with phrase «because aerosol cooling»

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.

The observed temperature hasn't risen that much because aerosol cooling parameters are postulated by climate modellers which alledgedly mask the «real effect».

Not exact matches

Forest fires in the lower latitudes, however, are actually beneficial sources of black carbon because it is coupled with organic aerosols and ends up reflecting light and heat, causing the surrounding area to cool.

Indeed, conventional wisdom held that higher levels of aerosol pollution in the atmosphere should cool the earth's climate because aerosols can increase cloudiness; they not only reduce precipitation, which raises the water content in clouds, but they also increase the size of the individual water droplets, which in turn causes more warming sunlight to be reflected back into space.

One could also argue that the stratosphere isn't being loaded with all sorts of aerosols right now because of «social interia» and that the «correct interpretation of climate science» is therefore that there's a strong cooling commitment.

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.

Further, during volcanic eruptions the ocean cools but for another reason: because volcanic aerosols shade the sun and thus the oceans are heated less than normal.

The changes seen in the MSU 4 data (as even Roy Spencer has pointed out), are mainly due to ozone depletion (cooling) and volcanic eruptions (which warm the stratopshere because the extra aerosols absorb more heat locally).

«A rapid cutback in greenhouse gas emissions could speed up global warming... because current global warming is offset by global dimming — the 2 - 3ºC of cooling cause by industrial pollution, known to scientists as aerosol particles, in the atmosphere.»

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.

So, in the beginning there was cooling from aerosols and warming from CO2, and the cooling won out because there was so much aerosols.

The second aerosol indirect effect is more likely to cause cooling than warming because, to the best current knowledge, high clouds are more likely to warm climate, whereas low clouds are more likely to cool.

... 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.

Sulphate aerosols have a cooling effect on the climate because they scatter light from the Sun, reflecting its energy back out into space.

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.

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.

While the aerosol influence last less than a decade, the influence on surface temperatures continues because of the slow mixing of cooled waters on the ocean surface.

It's because both land and ocean surfaces are heated by shortwave solar radiation and where aerosols reflect SWR equally well over land or water and where greenhouse gases work by retarding the rate of radiative cooling which is not equal over land and water.

Because sunlight affects the maximum day - time temperature, aerosols should have a noticeable cooling impact on it.

The models do not accurately reproduce the change from sloping to flat during mid-century, but that is very possibly because they underparametrize mid-century negative aerosol cooling.

Christy is correct to note that the model average warming trend (0.23 °C / decade for 1978 - 2011) is a bit higher than observations (0.17 °C / decade over the same timeframe), but that is because over the past decade virtually every natural influence on global temperatures has acted in the cooling direction (i.e. an extended solar minimum, rising aerosols emissions, and increased heat storage in the deep oceans).

Other influences: aerosols, likely cooling, though the temporal variation is key (eg, they are net cooling overall, but their trend in the past 20 years may actually be net warming because of sulfate pollution control in the industrialized nations).

The input of assumed anthropogenic aerosol cooling is needed because the model «ran hot»; i.e. it showed an amount and a rate of global warming which was greater than was observed over the twentieth century.

The approximate stand - still of global temperature during 1940 - 1975 is generally attributed to an approximate balance of aerosol cooling and greenhouse gas warming during a period of rapid growth of fossil fuel use with little control on particulate air pollution, but quantitative interpretation has been impossible because of the absence of adequate aerosol measurements.

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.

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.

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)

Because the cloud effect is self limiting, it's instantly reversible as ice cover stops fauna and flora from producing aerosols in the cooling World, so allows the IA.

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

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.

«About» ought to be in italics because we really don't know how much cooling is caused by other emissions, like particulate aerosols that go up the smokestack along with the carbon dioxide.

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.

The other side of the coin is that for long term warming, the cumulative emissions of CO2 are dominant, even if in the short term changes in its emission are relatively ineffectual, even more so because they are often combined with emissions of cooling aerosols.

The approximate stand - still of global temperature during 1940 - 1975 is generally attributed to an approximate balance of aerosol cooling and greenhouse gas warming during a period of rapid growth of fossil fuel use with little control on particulate air pollution, but satisfactory quantitative interpretation has been impossible because of the absence of adequate aerosol measurements.

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.

Because no - one believes it presents any contradiction to the idea of aerosol cooling?

Among the issues discussed: solar energy variations that could contribute to the ebb and flow of ice ages, new understanding of ice ages and the possibility of cooling because of aerosol pollution, but also the possible confounding factor of increasing greenhouse gases:

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.

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

Because predictions of a cooling planet made during the 1970s — a number of researchers then believed that increases in the emission of aerosols, such as dust and smog, could put the planet on a path of sustained cooling — turned out to be wrong, climate deniers argue that the current projections could prove to be just as fallacious.

Overall, the evidence suggests that the aerosol buildup is causing a net cooling both because aerosols reflect incoming sunlight back to space (a direct effect) and because they «seed» cloud droplets, causing clouds to become brighter and more reflective (an indirect effect).

The GCMs appear to be wrong not only because they assume too much aerosol cooling, but also because, a) most of them arrive at a too - high temperature change between the 1880 - 1890 and 2000 - 2010 time frames, and b) because they generally predict too much ocean heat uptake, particularly in the Southern Hemisphere.

Their model found that the unprecedented increase in monsoon activity over the past 30 years is «due possibly in part to» the rise of CO2 in the atmosphere, but they said the result could be an overestimate because the authors didn't consider the impacts of aerosols, which cool the atmosphere.

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.

Then because the cooling periods could not be emulated, they turned up the aerosol knob.