Sentences with phrase «volcanic aerosols only»

Not exact matches

While measurements of aerosol absorption in ultraviolet do not differentiate between the smoke, dust and ash aerosols, only volcanic clouds contain significant abundances of SO2, so satellite measurements of SO2 are especially valuable for unambiguous identification of volcanic clouds.

For instance, simulations were run that only used the changes in volcanic forcing, or in land use or in tropospheric aerosols.

Given the total irrelevance of volcanic aerosols during the period in question, the only very modest effect of fossil fuel emissions and the many inconsistencies governing the data pertaining to solar irradiance, it seems clear that climate science has no meaningful explanation for the considerable warming trend we see in the earlier part of the 20th century — and if that's the case, then there is no reason to assume that the warming we see in the latter part of that century could not also be due to either some as yet unknown natural force, or perhaps simply random drift.

The observed temperature evolution can of course only be the result of all forcing factors combined (including solar variability, volcanic eruptions, and man - made aerosols)-- not CO2 alone.

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.

Because such a struggle is the only reasonable explanation for why you fighting so hard against the idea that a dissipation of aerosols requires an absence of further volcanic activity.

There are multilple causes cited in the post above volcanics, aerosols, solar (which by the way the recent minima was only unusual by its longevity not its amplitude) but we can leave Hansen 2011 to rebute your point 1

We also use five - member ensembles of simulations with greenhouse gas changes only (GHG), volcanic and solar irradiance changes only (NAT), and aerosol changes only (AER) over the period 1850 — 2010.»

The only factors under natural forcing was solar irradiance, volcanic aerosols.

Since the last ~ 17 years is the only period with known low volcanic forcing and since aerosol forcing is one of the largest unknowns, that makes the last 17 years the longest useful period of that type.

Robock found that the forcing which most closely mirrored the actual temperature observations was volcanic aerosols: «volcanic dust is the only external forcing that produces a model response significantly like the observations».

««Climate model simulations that consider only natural solar variability and volcanic aerosols since 1750 — omitting observed increases in greenhouse gases — are able to fit the observations of global temperatures only up until about 1950.»

However, there is not compelling evidence that anthropogenic CO2 was sufficient to influence Earth's temperatures prior to 1950, i.e. «Climate model simulations that consider only natural solar variability and volcanic aerosols since 1750 — omitting observed increases in greenhouse gases — are able to fit the observations of global temperatures only up until about 1950.»

Aerosols emitted for only a short time would have minimal effects that subside very quickly.The industrial aerosols are rich in SO2, while apparently, the Chilean volcanic eruption did not (according the news item) spew enough SO2 into the atmosphere for discernible climate Aerosols emitted for only a short time would have minimal effects that subside very quickly.The industrial aerosols are rich in SO2, while apparently, the Chilean volcanic eruption did not (according the news item) spew enough SO2 into the atmosphere for discernible climate aerosols are rich in SO2, while apparently, the Chilean volcanic eruption did not (according the news item) spew enough SO2 into the atmosphere for discernible climate effects.

As for aerosols, you seem to be under the illusion that the only thing that matters is volcanic events, and even then only that they happen.

We have poor direct information on aerosols, but the fossil fuel consumption rate is low, and there is only one major volcanic episode, so we can assume aerosol cooling is not significant.

Instead of responding only to the cooler temperatures, the tree rings also included signals from reduced light availability (from the shading effect of volcanic aerosols) and the two effects together produced a signal greater than what would have been produced by cooler temperatures alone.

The only direct real - world inputs to these models, in a climate change simulation context, are changes in atmospheric chemistry and composition (such as increasing greenhouse gases, or changing volcanic aerosols) and changes in solar radiation.

Backing that up, NASA says that 1) sea surface temperature fluctuations (El Niño - La Niña) can cause global temperature deviation of about 0.2 °C; 2) solar maximums and minimums produce variations of only 0.1 °C, warmer or cooler; 3) aerosols from natural sources such as volcanic eruptions (Mount Pinatubo for example) have caused average cooling of 0.3 °C, but recent eruptions have had not had significant effect.

This is that if downwelling sunlight is reduced via aerosols, whether direct or indirect, the efficacy is ~ one... but if downwelling sunlight is reduced the exact same amount via volcanic aerosols, the efficacy is only 0.75... and I have never seen a modeler or anyone else even attempt to justify that gaping hole in the theory.

The basis for this statement is comparison of global climate model simulations with observations for the 20th century, for simulations conducted with natural forcing (solar and volcanic) only and natural plus anthropogenic forcing (greenhouse gases and anthropogenic aerosol).

Whereas all of the IPCC AR4 models agree that the warming observed since 1970 can only be reproduced using anthropogenic forcings, models disagree on the relative importance of solar, volcanic, and aerosol forcing in the earlier part of the 20th century (IPCC AR4 WGI Section 9.4.1).