Sentences with phrase «much aerosol cooling»

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.

Not exact matches

Exactly how much natural aerosols from volcanoes and sea spray cool the climate remains an elusive question

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.

That leaves a gap as much as 5 km thick in the lower stratosphere where climate - cooling aerosols can persist, yet not show up, in satellite data.

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.

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

While it is true that, holding everything else equal, an increase in how much cooling was associated with aerosols would lead to an increase in the estimate of climate sensitivity, the error bars are too large for this to be much of a constraint.

But the cooling effect of aerosols incorporated in current models is much larger.

Neither is there much change in (cooling aerosol) SO2 emissions in the past years around the equator (China, India), compared to the previous period.

This imbalance is really an important quantity — estimates of how much warming is in the «pipeline», the size of the aerosol cooling effect etc. all depend on knowing what this number is.

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.

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 correctly).

The Echam4 model overestimates temperatures with GHGs alone, and gives too much cooling when including aerosols.

Since aerosols last much longer in the stratosphere than they do in the rainy troposphere, the amount of aerosol - forming substance that would need to be injected into the stratosphere annually is far less than what would be needed to give a similar cooling effect in the troposphere, though so far as the stratospheric aerosol burden goes, it would still be a bit like making the Earth a permanently volcanic planet (think of a Pinatubo or two a year, forever).

The Nature commentary by Penner et al. on which this argument is based actually says that on top of the global warming caused by carbon dioxide, other short - lived pollutants (such as methane and black carbon) cause an additional warming approximately 65 % as much as CO2, and other short - lived pollutants (such as aerosols) also cause some cooling.

But aerosol cooling is more immediate, while greenhouse gases accumulate slowly and take much longer to leave the atmosphere.

The sensitivity of the earth's climate vs. GHG depends on how much GHG warming has been offset by cooling from aerosols.

That makes it quite doubtfull that the same aerosols would have had much impact in the previous period of temperature standstill / cooling.

The anthropogenic forcing on the climate is multifaceted, with both warming and cooling sides — cooling from aerosols over shorter time frames but warming from GH's over much longer time frames.

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

I'm still struggling to see why a permament cloud of aerosols from a nearby volcano is unable to measurably cool the surface but much less powerful chimney stacks are able to cool sorrounding regions to the extent that this cancels GHG warming.globally.

«Modelers defend this situation... by arguing that aerosols have cancelled [sic] much of the warming (viz Schwartz et al, 2010)... However, a recent paper (Ramanathan, 2007) points out that aerosols can warm as well as cool»

My own reading of the evidence is that much of the fluctuation during that interval was due to natural unforced variability from internal climate dynamics, with aerosols perhaps adding some cooling after 1950 but not necessarily a major player before 1950 nor necessarily an exclusive player from 1950 to the mid 1950s.

If the presence of aerosols has been causing unnatural cooling for thirty years how much of any subsequent warming is due to their removal.

And the reason is ostensibly that cooling aerosol production prior to 1950 negated much or all of the warming effect of GHG production.

«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.

He also found that much of the effect was due to natural aerosols which would not be affected by human activities, so the cooling effect of changes in industrial pollution would be much less than he had calculated.

Matt Ridley writes, «Mr. Lewis tells me that... aerosols (such as sulfurous particles from coal smoke)... have much less cooling effect than thought when the last IPCC report was written.

This means that volcanic aerosols have minimal long - term cooling effects and therefore, the warming effect of CO2 has to be much lower than assumed in Hansen's climate models and thus climate sensitivity estimates must be lowered even further.

Hi Karsten, If you're still reading this, I'm still trying to get my head around the notion that we don't need to see much cooling under the most aerosol - laden areas for the direct effect to be strongly negative at the global level.

In fact, I don't think I have much to argue about your initial post but it does relate directly to the famous issue of the 40s - 70s global cooling, and the alleged aerosols explanation.

perseus @ 2 - the pre-1975 ocean data in this paper look similar to the surface data, in that they did not warm much during mid-century, likely due to aerosol cooling offsetting greenhouse gas warming.

This thinning, which can decrease the ozone concentration by as much as 70 percent, was caused by the rampant use of human - made chlorofluorocarbons (CFCs), organic compounds that were once widely used in cooling systems and aerosols.

If the global models are correct in this respect, the implication is that much of the observed recent excess warming of the Atlantic is due either to internal mechanisms (variability in the Atlantic Overturning circulation, for example) or non-greenhouse gas external forcing (e.g. recovery from strong aerosol cooling).

If there's much less mid-century cooling, that will conflict with an assumed strong aerosol cooling effect in the models, and by implication, a strong CO2 warming effect.

I also predict it will be accompanied by studies showing either: a) The quantity of atmospheric aerosol from the 40's -70's is much less than previously thought b) The cooling effect of aerosols is much less significant than previously thought

Although previous research had seemed to indicate that aerosols could create a general cooling effect in the atmosphere — thus helping mitigate the effect of global warming — a new study has revealed that they may in fact warm it just as much as greenhouse gases.

In fact, since as you can see, most of these aerosols are in the norther hemisphere, one would expect that, if cooling were a big deal, the northern hemisphere would have cooled vs. the southern, but in fact as we will see in a minute exactly the opposite is true — the northern hemisphere is heating much faster than the south.