Mainly the size of the cooling effect due to human aerosol pollution remains highly uncertain, and while the oceans have been warming rapidly, just how rapidly is another unsettled question.
One of the most insistent voices arguing against e-cigarettes has been the World Health Organisation, which has called for a ban on vaping indoors, citing evidence that "suggests exhaled e-cigarette aerosol increases the background air level of some toxicants, nicotine and particles".
Packing them inside a nanoparticle and unloading them in the form of a water-based aerosol spray is therefore tricky.
Wait too long and the lipid casing is digested by lysosomes, the cellular waste-disposal units.The drugs can be inhaled as an aerosol spray through a nebuliser, a device which turns liquid into fine mist.
In that year the Nepal Climate Observatory - Pyramid, in the Khumbu valley, began a full-time study of aerosol particles, soot among them.
Laboratory techniques such as photoacoustic measurements (a biomedical-imaging method used to investigate cancers) make it possible to look at how individual aerosol particles behave.
Clouds grow on aerosols: that is, water droplets or ice crystals form on aerosol particles.
But one particular aerosol is more influential than had previously been calculated.
And aerosol cooling is likely to be reined in by China's anti-pollution laws.
This is found in tap water, but remains harmless unless turned into an aerosol and inhaled precisely what happens when bug-laden water is forced at high pressure through a showerhead.
The red to green ratios of his pictures before and after the dust event (analysed as the Tate paintings were) matched well with measurements of aerosol optical depth collected on site, and with photographs taken there too.
