The authors examine various potential causes
of aerosol increases and identify a number of small volcanoes over the last decade as the most plausible source.
Expectations of decreases in large source regions such as China [195] may be counteracted
by aerosol increases other places as global population continues to increase.
Expectations of decreases in large source regions such as China [195] may be counteracted by
aerosol increases other places as global population continues to increase.
On a separate point, my understanding of the global dimming issue is that aerosols responsible for dimming were possibly masking a higher climate sensitivity to GHG increases than would have been inferred in the absence of this dimming, suggesting that further increases in GHGs without
compensating aerosol increases would result in more warming than would have been predicted prior to the acknowledgement of the global dimming phenomenon.
The political «solution» is: Unsupported claims of
large aerosol increases which allows the fiction of the a high climate sensitivity to be maintained, leading to alarming and false predictions of catastropic future warming.
We find that the increase in emissions of inorganic aerosol precursors is much larger than the
corresponding aerosol increase, reflecting a non-linear atmospheric response.
(See table 4, AP experiment, in the paper we turn the argument around and discuss the effect
of aerosol increase).
If the direct effect of
the aerosol increase is considered, surface temperatures will not get as warm because the aerosols reflect solar radiation.
This pattern of global temperature can be explained by a combination of different influencing factors over time (increasing solar activity plus moderatly rising greenhouse gases until 1940; cooling through strong increase of aerosols / fading of solar activity increase / still moderate GHG rise until 1970; strong increase of GHG emissions / reduction or inversion of
aerosol increase and the related cooling after 1970).
If the effect is real though, one would want to see whether it could be tied to anything else (such as forcing from greenhouse gas or
aerosol increases), and indeed, whether it had any implications for wind - generated electricity, water evaporation etc..